you probably dont give a damn but does anyone know a way to log back into an instagram account? I somehow lost the password. I appreciate any tricks you can give me!
@Bishop Jaiden thanks for your reply. I found the site thru google and I'm trying it out atm. Looks like it's gonna take a while so I will get back to you later with my results.
I'm glad I found your video's about this issue because now I can tell the difference between just a dirty throttle body and a failed IAC valve without a scan tool. I have the '03 4.6L Ford engine and usually once or twice a year, I'll spray clean the MAF sensor and throttle body assembly during the same service. My P74 Crown Vic has 122K miles and at some point I'd like to perform a mechanical inspection and service of both IAC and EGR valves to ensure both are doing their job and offset any future malfunctions. My last 5,000+ mile journey resulted in 23-26 mpg average which tells me engine is still within spec tolerance.
James Barrow, to continue further just an hour ago I decided to perform a mechanical inspection and clean of MAF sensor, throttle body, and a first time ever inspection and clean of IAC valve. My Crown Vic is 12-1/2 years old and 122K original miles and MAF sensor just slightly dirty, same for throttle body, and IAC valve still like new with light deposit. Cleaned all three and performed 10-mile drive for computer to relearn and set new adjustments and car idles and drives just like it did when brand new which it still looks and drives like. Next service is EGR system for inspection and clean which based on IAC valve, I expect no surprises.
I don't have that expensive scanner, but found that there's 2 screws in the back of the IAC valve on my pickup I took it apart and as soon as I did you could here the rod inside move, when I put it back together and back on the vehicle it would idle smoothly. I tested the ohms across the IAC Valve and its within spec of 10-14ohms, but that don't mean the valve itself isn't stuck, so in my case taking it apart got the valve unstuck...the truck sat for 4 years, so its within reason the valve would be stuck I guess, ordered a replacement valve, but I bet if I had your scan tool I'd have some pretty similar issues that your scan tool was showing us. This video was a great help. My truck wasn't doing the cold high idle either, it was probably down around 500rpm or so even cold, so that's most likely what got my attention at first was the weird low idle especially sense I have another truck with the same engine next to it that revs much higher when doing a cold startup. Vehicle is a 1987 Ford Ranger 2.9L V6, and the other truck sitting next to it is a 1988 Ford Bronco 2 2.9L V6. Ironically I have 2 vehicles with the same engine, helped out with some diagnostic stuff being able to look around both vehicles and see what's out of place, and test parts to see what ohm readings I was getting on the known good vehicle VS the one that decided to go on vacation for 4 years LOL.
You are correct about a TPS voltage issue. It should be around .98 to 1.0 volts on all Fords I've ever seen. You had an initial hang up that was really high. But after the fix it was still 1.12v. Either somebody adjusted the idle stop screw up a bit to try and fix this idle issue, or more likely you have a dirty throttle body. The IAC is designed to run in the middle of its range with the engine warm and AC off. Since its range is 20 to 60%, a 40% duty cycle would be about right. 35 to 40% with air off is good. This one is a little high despite a slightly high tps, possibly indicating a dirty IAC and/or throttle plate. I have had some luck with cleaning the mechanical half of the valve. It's worth a try since the valve is 80 bucks.
omg i have a 2006 Chrysler pacifica i thought it was the transmission it would self acelerate and stall especially when i would turn ac on then i would turn on and it would shut down right after .tommorrow im gonna change the idle air controller your a life saver.
I was having this exact same problem on my 2002 Mercury Grand Maquis. I used my daughters cell phone to tap on the idle air conrol valve and this did the trick. Going to have a friend who is mechanically savvy clean it out for me. Thanks for this video!
Excellent information that explained on a higher technical level the I.A.C.V. operation. My Ford has hard cold starting, needs the throttle cracked open slightly, yet runs and idles perfectly off idle. I'm thinking sluggish solenoid when cold. Now I know how it all works. Thanks for posting.
This video is going to be referenced a lot for the Mazda community as well. I see a lot of people that complain of no-start unless the gas pedal is down. I always told people to start with a fuel pressure regulator diagnostic first. Didn't know the IAC would fail like this. Just learned an important lesson thank you!
Had this issue at 80K took iac out cleaned it problem is back now....at 130K. I was afraid it might accelerate suddenly and potentially cause an accident but it's never done that (except once or twice which was my fault as the pedals are too far apart and not designed for tiny little feet like mine). I'm just grateful that mine didn't need to be included in the headlight recall. That's one thing I don't have to worry about going bad. I leave the heat off and I like it just fine. I also love how the electrics are super watertight unlike my Pontiac. I can just dump S100 on that motor and rinse it down with a pressure wand and get all that grime off so I don't have crud everywhere in my engine bay. Like a motorcycle or a semi truck just AWESOME!! I recommend you try it! Your brand loyalty will be insane and you'll buy another Ford.
Man, I am so sick of my crown vic not idling. it is always on the worst day. Its a guarantee that on a 0F day, when you want to let the car warm up outside, the car will not idle without my foot being there holding down the throttle. Well, its gotten worse in the past week.. You sir, have solved my problem with this video. a new ICV is on the way. Thanx for the hard work to make this great vid!
Thanks so much I've been working on my own car all my life 😊 However shit like the iac and other sensors irritates the shit outta me. I kinda figured this, but needed to know for sure the reason for my stalling. You're awesome very knowledgeable and I appreciate YOU!! Always looking to save money. Widower our here taking care of my business 💯😊
Sir your videos are awesome! your very talented in what you do. thank you for the information you provide, it helps me very much in learning how different components work. keep up the good work!
I might also add that it is educational to view the PIDs for TPS voltage, IAC duty cycle, Desired RPM, Engine RPM, and Mass Airflow while experimenting with adjusting the minimum airflow (idle speed) screw. This will teach you a lot about idle airflow. Idle airflow is made up of airflow that leaks by the throttle plate, and IAC airflow together. An increase in one results in a decrease in the other.
Based on a few videos of yours on this subject, my impression is that one of these 2 pin Ford / Mazda IAC valves can be defective, yet not cause a code, not fail a resistance test or show any issue on an oscilloscope, like the stuck closed valve in this video. Since the problem can't be directly detected, I'm assuming one has to go through a process eliminating every other possibility until nothing is left but the IAC? What is it exactly that causes these valves to get stuck like that? Carbon buildup or some other mechanical issue? I've read on a few Mazda forums of a problem in which these types of valves partially fail, i.e. the car starts, you get flair and extra air until the engine warms up, but once warm the idle is low, and if you put loads on the engine like the AC, high beams, or hold the break down in gear, the rpms will fall and the idle will get very rough, yet there won't be any codes and the IAC passes the WSM prescribed tests. Have you ever encountered this problem? What might be the underlying cause of such a problem. Sorry if this is too much for a youtube comment!
very interesting i have a 99 mazda v6 198,000 miles when ever i get to a red light. after 40 seconds my engine feels like a stallout but hangs... but with the foot on the gas its feel good. i will take the throttle body apart and clean the IAC and see what happens .....thank you for the informative video.
Hi, scannerDanner, I have a 97 legacy outback with 2.5. I am getting the same code P1507 as you discussed in one of your videos. I cleaned out the IAC and checked for air leaks with carb cleaner. Car idles well, however, check engine light is triggered after 5-10 minutes of driving. The car cuts out and restarts immediately. the resistance on the control valve connectors are 1-2 and 2-3 are 9.3 ohms off the car. I have tried to clean the throttle body but no change. Any suggestions? thx in advance
Great video I learned a lot. My nephew has 1994 Thunderbird a 3.8 V6 that he just bought from a friend of mine with 153K and he`s having the exact problem with the Idle.
I have an 87 Ford econoline 302 and replaced the IAC but problem still exists. It starts fine and idles great till warmed up. Warmed up it idles fine in gear but as soon as it is placed in park/neutral it dies. I would bring it in to you but I am in Yuma Arizona. Any ideas?
Thanks, good video ! Having a huge problem with my Mustang 2004/ 3.8 litre ?? After changing fuel pump bigger, 255 lph, and throttle body to 70 mm, idle has been sky high?? I know there has to be vacuum leak somewhere, since AC works, and when blowing to face, suddenly changing to windshield, like defrost??, without touching anything??Codes are : P0507, and P0405?? Did change DPFE sensor ( tested it, fine!), TPS, IAC sensor, and EGR valve! Can't find any leaks under hood, sprayed all vacuum hoses?? Did check canister solenoid in rear, 12 V coming in, closes after applied 12 V??, did not change that?? No leaks around tank?/Did check canister purge valve in a front?? Could not test that?/, cleaned out, 12 V coming in?? Could that be open all the time, making idle that high??Did have " check engine light " on even before changing fuel pump and throttle body, every now and then, telling large vacuum leak, and " check fuel cap", did change fuel cap, no help?? Do I need smoke test next??? What could be reason for this leak/ high idle??? Going crazy here, thanks =) Ps. could there be a leak above fuel tank???
Dave, great video ! I watched the whole thing. Any suggestions would be greatly appreciated... I have a 2004 Grand Marquis. Engine light came on last Sunday after I got gas. This week I had my mechanic check the car. He replaced the #5 coil and all plugs, even though previous plugs and coils had less than 11,000 miles. He cleaned and flushed out the throttle body and ran a computer electronic balance test. I drive the car about 60 miles one week later (today) and stop at the same gas station, and when I start the car up, the engine light came on again. I reinstalled the gas cap, but no luck shutting the engine light off. Also checked the fuel send switch in the trunk, and it was not tripped. The symptoms I'm having are occasional rough acceleration from a dead stop, and occasional random momentary de-acceleration. The other symptom is that when I come to a red light, and the car has sat idling for about 45 seconds or more, the engine idle speed slows down and is noticeably rough. I plan to tell my mechanic what you did with the idle air control valve / motor. Could that be my problem? Also, another video showed a "throttle position sensor" which some guy replaced on his C. Vic police interceptor. Should I replace that? The mileage on my car is 224,500. I am the original owner of this Marquis, and have changed oil religiously since purchasing the car. I also have changed the transmission fluid about every 40,000 miles. Thanks and hope to hear from you. Tom in Miami, FL
I have a 1989 5.8 . the engine starts and runs nice till it warms up. then the idle gets rough and will continue to run while more air gets drawn thru the iac valve then it idles up for a while and smooths out but will drop again. it just kinda plays that game. is their ever a time that the iac valve holes in the throttle body ever stop sucking air? like does the vale supposed to shut off that air flow or just restrict it?
My 96 Lincoln Town Car idles fine at startup; however, tends to stall at times when I put it on drive or when I stop at an intersection. Is that an IAC issue as well?
Sure sounds like it my friend. Does it ever stall while your foot is on the gas pedal? If no, and it only stalls when your foot is off the pedal, then we definitely want to focus on the IAC
@@ScannerDanner The last time I drove I took off after stopping at an intersection and with my foot on the pedal it felt like no fuel was going thru as I stepped on it more and then it stalled. Put it on neutral as car was rolling and started the engine back up.
@@Daluch3 focus on your throttle position sensor, these were common failures on your model and your symptoms sound more like this is where we need to focus
@@ScannerDanner Forgot to mention I checked the Check Engine light with a code reader and it shows the current fault as P0174 Powertrain System too Lean (Bank 2) and a Pending Fault P0171 Powertrain System too Lean (Bank 1). The PCV valve is brand new so I know that's not it.
I'm having problems with my 1999 Dodge Durango 5.2. My problem is that the vehicle has a hard time starting once warm than sits for a bit, I have to give it some throttle than fires up, runs fine. Fuel pressure seems to hold fine once turned off. Going to check out the IAC counts but not sure if it could be related. Maybe stays closed? but first start of the day etc.. starts right up no problem.
hey, its Rich, a former student of yours not too long ago. I have a mazda 6 at work. feels like it wants to stall at idle only. runs great while driving. never stalled on me. I think iac could be bad. m not sure where to check next. no codes
enjoyed the video, like always and thanks. you stressed concerns about TP voltage that someone may have adjusted the idle stop. did you address that issue? do you think the voltage was a bit high? are you thinking buildup in the throttle body may be the reason? thanks.
I have problem with my 2000 Ford Focus. Just replaced the TPS and now the car revs up so high on idle and the engine light came back on. You think smacking the IAC will help?
You Guy's are awesome i have a 98 crown vic mine has the issue when its cold outside keeps stalling unless i hold throttle a little for about 5-10 mins then runs great will these act up more when its cold outside thanks from Joe!
Hello, I have a 2003 Ford Expedition 4.6 v8. The vehicle idles at around 1200 rpm in park and neutral. When i put it in reverse or drive it idles fine. The main problem i am having is that the lights will go bright then dim and the vehicle will die and i will lose power steering and brakes. It starts back up in park immediately, I dont know if it is relevant to the probem but it seems like after it rains it always has electrical issues, all the dash lights come on and pulsate and still drives fine. Any information would be appreciated ScannerDanner!
How do you differentiate between a bad IAC and a dirty throttle body? Won’t in both cases they have high IAC counts that doesn’t allow vehicle to idle?
I've got an 01 expedition that hasn't idled right since I replaced the intake gasket. It does the flare up that you speak of, then drops pretty low, then planes out just a little lower than what I think it should be. It stalls every now and then but not always. There is a code, I forget what the number is but it basically says that it's idling to low to properly run all the accessories. Any input would be great.
I have a 97 Ford F-250 5.8L that does this same thing. However, whenever I unplugged one of the vacuum lines, it starts right up (doesn’t idle perfectly) and still tries to stall whenever I try driving it above 30mph. It ran fine before and just started this recently.
Hi, I wanted to ask a question regarding the operation of IACV. I know that at start up, IACV is fully opened by ECU to help in starting and that it is opened during decelaration with throttle closed to ensure smooth running of engine. Should the IACV (stepper motor type) be open when the throttle is open (partially or fully)? With engine cold and hot. I noticed that my IACV (stepper type) does not fully close even when throttle is opened at least with cold engine. Its not for a specific vehicle but I have a pre-OBD-2 vehicle (European) of Renault.
scannerDanner....i have a 2003 mach 1 that's giving hinging idle issues..the revesre of what thus video concludes I guess. have u encountered this issue, any help would be appreciated. tps is non adjustable on this year but when I disconnect it the idle is normal
When they run rough, then die, will I see the duty-cycle % drop? Because the valve has carbon deposits in it and cannot maintain correct duty-cycle? It is hot weather here so on mine I find that with AC on, it increases duty-cycle enough to prevent stalling : )
Great video I have a '93 Grand marquis 4.6, it will stall and hesitate and surge, usually stall if you give it too much gas. Feels like a miss going down the road you can feel it bucking slightly. Can't figure it out! New MAF and intermittent check engine light. Please help!
Not enough info to help you, sorry. What code is setting? When did the problem start? Have you tested fuel pressure? Your problem could be withing the fuel system, ignition system, or even engine mechanical.
What if the flare up upon cold start, starts off too high like 2200-2500 and then drops to about 1500 when engine is cold. Is the IAC bad? What does this say about the IAC? What causes it to cold start too high? Drops down fine after to 800 RPM when warm.
wow!!, i couldnt believe that this actually worked. i got my wife to hold the gas while i taped the housing with vice grips and the engine reved up and the car idled on its own.
I sure wish I could bring my dead 95 Mark VIII to have you diagnose it! It's been dead since January 2018. 😭 I just can't bear to part with it though, keep thinking I'm going to fix it one of these days. 😒😔
2005 pt cruiser gt stalls and then starts after setting iac code 508 O2 codes 32,38. It wont run when i unplug the IAC it stall. I bleave that the curcit is good. If it runs with the sensor plug in. And the AIC must be sticking. Or cant keep up with the PCM. And its giving the O2 sensors the high voltage.
Hi , I have an 86 f150 and have added a Innovate MTX-L wideband , mine is doing the same thing , whats happening is the mixture starts off ok for a cold engine then it gets richer and richer as the motor warms up , it does the rolling surge and dies when it hits 10.9:1 , as someone mentioned maybe the CTS sensor maybe telling the computer its a cold engine ? or the IAC is doing weird things and giving engine less air . Read more 15 minutes ago
My 03 f150 stalls out but ONLY when in park and after it warms up, which definitely leads me to believe it’s the IAC. Starts and drives just fine, and doesn’t idle rough when in gear (every once in a while at a stop light it acts up but has never stalled). Think it’s getting pretty dirty especially given it has probably never been replaced in the last 16 years. Guess I’ll give it a go. Didn’t throw a code
Hi Paul, A query please. I just fixed a stuck Idle Speed Actuator Control on a Hyundai Accent 2004, with open-close bi-solenoid PWM control (not a stepper) and MAP engine. It was stuck partly open with a 1500rpm idle speed. Sounds simple. What threw was the code p0121 TPS/APP range performance not p0507 idle too high. I also had a Desired Idle Speed on 1500rpm, oddly, rather than normal 750rpm. I suspected the ISA but the odd code and DESRPM made me spend time eliminating the TPS/APP before attacking the ISA. It cleaned up and works fine. But here's my question: why a DESRPM of 1500?? After the fix the DESRPM is normal. My explanation: MAP engine detects low Man Pressure, ECU desires higher idle RPM as a result, like a cold engine?? Maybe it desires the higher RPM, but senses a range performance from a closed RPM/throttle plate and APP at normal idle??
I don't have answer for you on the desired idle number. A TPS problem would definitely cause what you are describing. MAP signal wouldn't be the answer as manifold vacuum at 1500 is typically identical to idle speed. I've never seen a sticking IAC valve (open) cause a desired idle command to increase
I have a 2009 Altima. It will start just fine but will stall out when placed in gear. If I give it yes immediately after placing it in gear it will drive fine but will stall again at stops unless I put it in neutral. Amy ideas?
In all honesty, If I was a gambling man, this vehicle probably has ignition coil issues but we do not 'change parts purely on speculation' Awesome job yet again Paul, there always has to be a plan B if plan A fails. Ah, and do not worrying about the camera work, it is the content that matters.
2;/17/2021 I did not get a reply from Scanner Dave. However this video is as good as you will find on Marquis & Crown Vic idle and acceleration problems. Here's what I suggest anyone should do who has a Crown Vic or Marquis from the late 1990s to 2011 models with idle & acceleration problems. IF changing coils and plugs did not solve the problem, then do not hesitate to change both the throttle position sensor and the air intake control valve. (I have a 2004 Marquis). The throttle position sensor is $36.00 at Auto Zone, part #TPS245. The air intake control valve (also called a Throttle Air Bypass Valve), part #TV2004, cost is $75.00. Replace these two parts, BEFORE spending a lot more on a new fuel pump and installation. These two parts may solve your problem entirely if your plugs and coils are working correctly. Also check the connections to all 8 coils to make sure the coils are properly connected. One loose coil connection can trigger the engine light, and create idle and acceleration problems. Ebay has the same parts mentioned above, but made by different manufacturers for less money if you don't have much to spend. The other things you may need to have done is to have the throttle body assembly cleaned out, and the air intake sensor cleaned. There are youtube videos that show how to clean the air intake sensor. I tried cleaning my own air intake sensor, which is close to the air filter. Cleaning it did not work. The air intake sensor is a different part than the two parts mentioned above, located inside the air duct tube by the air filter. You should see an electrical connection for this part on top of the air duct tube. 2/20/2021 update. Unfortunately, I drove the car this weekend after replacing the parts mentioned above. I noticed the same thing started happening after I drove about 20 miles. One thing I noticed under the hood is that (standing in front of the car, the coil closest to me on the right) the front right coil is loose, very sloppy. I will have the mechanic check it and update this post. I tried pushing in down onto the spark plug, but it's still very loose.
I personally don't know of any IAC devices that incorporate a position sensor other than electronic throttle control systems. Stepper motor IAC don't have position sensors, but the PCM knows the position of it because it counts steps to get to the desired RPM. Some vehicles have software that will set idle speed low codes and some don't. This Merc doesn't, but it will set an idle air control system malfunction code (P0505) if you run the KOER test.
IAC's, and all types of solenoids, are feed-forward devices. Meaning the computer tells the solenoid what to do, and expects that it did it. There is no feedback directly from the device. In this case, it isn't necessary, as the computer knows what RPM it is commanding, and via the crank sensor it knows what RPM it achieved. Typically, a code can be set if the engine RPM is not able to be controlled.
I have a 1996 Lincoln Town Car: What if I have this exact problem but with an error code of P0125? Notice that the car won't start unless foot is on the gas pedal. Happens only during the winter; would have to wait till car warms up a bit before it will stay on. The other day no matter how long I let the car warm up with my foot on the pedal it didn't stay on (happen on a 20F day with snow), had to adjust the idle speed. Is it the same cause?
ProfounDisputes According to what I'm seeing, it's "insufficient coolant temperature for closed loop fuel control". My first thought is that the thermostat is stuck open, so the engine never comes up to full operating temp. The plus is that it's a quick, cheap fix, but there are people on here who know far more than I do.
I have a 1999 Ford explorer it idles then shortly after of I'm backing up it'll stall then I noticed the oils gauge jumps as well o did some research but Idk what it is any help
What if your problem is when it's cold out it won't idle and run have to keep giving it gas and keeps starting and keep starting it and after that at idle and run fine when the temperatures are warm like 55 or something and to start out with no problem and run but when it gets cold I have a hard time getting it to start to have to crank it 20 30 times and then finally she'll start and run you think that's the idle control valve?
If it is an idle control valve issue, it will run perfectly fine with a slight throttle opening. If you are having trouble keeping it running with a steady light throttle opening, it is NOT an idle control valve issue
My 2008 crown vic seems to run ok but randomly will die at idle. It always starts right up afterwards. It was happening about once a month but seems to be happening more frequently. Could it be the IAC?
my vx commodore 2001 in Australia it has rough idle or it seems to idle low to me, it does not stall but sometimes at trafic lights it will idle perfect, I am thinking the iac is not opening enough to let enough air in, when the car is going it is very good it is just idling low, what would be your say on this, when it idles good that tells me there are no air leaks and the injectors are good, I dont have any DTC and no engine light
My car is a 09 Chrysler 300 3.5 getting code fuel to leqn bank 1&2 or something like that. A light comes on 2 lines and a red lighting bolt when I drive it drives fine but when I go to stop or completely stop light comes on along with my slide control warning light and it shakes a bit and dies or stalls bad thinking it's a bad egr but sprayed it didn't look dirty u think it's my iac?
No, you don't have one, it's an electronic throttle body. Sounds like a vacuum leak. Do a keyword search "water test" on my channel where I teach you how to locate them.
So I changed my IAC and TPS on my bronco. when it starts up it flares up then idles down to normal. But after I drive it or tap the throttle and let off it stays idling high in park and neutral. What could it be? I have also changed my vacuum lines and air filter.
@@ScannerDanner It doesn't. I have changed it with a new part and it does the same thing. Changed the IACV also. I am starting to think it could be my throttle body. I am going to try to pick a used one up at a salvage yard and see if that fixes my issue.
Edmonton, Alberta, CanadaHave a 2003 Taurus 3.0 OHV....been having stalling and fast idle issues.speed will increase on it own. when stopped or in park If i turn on the air or the heater on DEF setting the RPM will fluctuate up and down then car will stall out.have checked for vacuum leaks and it seems ok
ok. im dealing with a 2003 ford taurus vín number 2 so itsthe ses model 3.0. iac throws i code to the obd 2 intermitantly. iac. pissed a voltmetter test and visual test. it dirty. but not bad. my problém is if u snad the thottle the engine will die out. and it will surge under a normal dříve. ideas?
hi i have a 2005 mercury mariner, the vehicle will sometimes run great then if im just in park it will die.had it scanned mechanic said was the fuel pump i replaced it and still acts up. watched your video on returnless systems so replaced fpdm. still acted up. well sometimes run 20 min or so fine and just idles down tell it dies and no help putting foot on gas pedal. starts right back up then does the same thing. if left for awhile it will crank and run fine then might act up never know. im in need of help scannerdanner.
@@ScannerDanner yes starts again but dies. Yesterday cleaned the grounds at pcm and fpdm after running half hour it died and sit the lean codes and for the fuel rail pressure sensor. This was replaced when I first got it back in August. Can I check the wires at fpdm with a multimeter and if so what should it read
yeah i thought so thanks i have a gmc 1500 slt big muffler 2 pipes gion in one coming out can i cut the muffler of and run staight pipe out would it make a diffence besides being louder
Would I be able to read this data with a global scan tool? My ford will drop the idle almost stalling the car when I'm slowing down or stopping for red lights in neutral/with the clutch in, the revs usually drop and rise 2-3 times before sitting stable. I suspect the IAC needs a replace but checking the data over like this would make me alot less anxious dropping money on a new part.
@@ScannerDanner Thanks man, it wasn't very dirty but it definitely improved after cleaning. I still do get an idle drop sometimes but its only significant when I've got a bunch accessories on (heater/fan + headlights but not AC(AC seems to fix it). Any idea where I can look next? IAC does work properly from what I've tested unless its just reacting slow for some reason. Turning the wheels while braking also makes the idle drop worse (only in neutral/clutch in again)
If you had an improvement with cleaning the throttle body, you may have a sluggish IAC valve. I hate to tell you to change it based on that alone. What is your idle speed with the IAC valve unplugged? It should just barely idle 400 rpm roughly
What year, make, model and engine? Have you adjusted the minimum idle speed? In other words, does it look like anyone has ever messed with the base idle set screw? th-cam.com/video/ayjhL9jpFH8/w-d-xo.html
I have an 02 sable that is doing this. I have already changed the IAC as well as the egr pressure sensor and solenoid. They were melted. Car still will not run without your foot on the pedal. Any suggestions. Also the iac is getting power.
David Pritchard catalytic converter is plugged up. Had the same issue on my ranger. Melted egr pressure sensor and hoses. I actually blew my air tube going to the egr too.
Arthur Metcalfe don't bother. these "cold air intakes" are nothing but a gimmick . your factory air box is NOT a restriction. In fact most of them draw underhood "hot air" after installing them. Completely defeating the whole purpose.
Are the duty cycle to percentage open numbers on Mazda's similar to those on Fords? As in 20% is closed, 30% no load idle and 50-60% fully open? When I read IAC% in a scan tool like ForScan, is that telling me duty cycle or actual percentage open?
Hello. I know its an old video but I want to ask if bad idle control valve does effect engine while driving? I have no codes and I know valve has to be changed and Im waiting for one to come very soon but when Im driving I feel hits from the engine. Spark plugs are new. Ignition coils checked.
Mine 2004 Town Car IAC went bad. Instead of putting the foot on the pedal it actually accelerate without the foot on the pedal. It can actually drive on its own by just steering and braking tho it would burn the brakes and stress out the transmission. Mechanic simply replace the IAC valve and runs back to normal. No problem since than. But is weird how IAC valve works
So refreshing to see a repair video where the mechanic knows WTF He is doing. Thank you .
you probably dont give a damn but does anyone know a way to log back into an instagram account?
I somehow lost the password. I appreciate any tricks you can give me!
@Kayson Terrance instablaster =)
@Bishop Jaiden thanks for your reply. I found the site thru google and I'm trying it out atm.
Looks like it's gonna take a while so I will get back to you later with my results.
I'm glad I found your video's about this issue because now I can tell the difference between just a dirty throttle body and a failed IAC valve without a scan tool. I have the '03 4.6L Ford engine and usually once or twice a year, I'll spray clean the MAF sensor and throttle body assembly during the same service. My P74 Crown Vic has 122K miles and at some point I'd like to perform a mechanical inspection and service of both IAC and EGR valves to ensure both are doing their job and offset any future malfunctions. My last 5,000+ mile journey resulted in 23-26 mpg average which tells me engine is still within spec tolerance.
James Barrow, to continue further just an hour ago I decided to perform a mechanical inspection and clean of MAF sensor, throttle body, and a first time ever inspection and clean of IAC valve. My Crown Vic is 12-1/2 years old and 122K original miles and MAF sensor just slightly dirty, same for throttle body, and IAC valve still like new with light deposit. Cleaned all three and performed 10-mile drive for computer to relearn and set new adjustments and car idles and drives just like it did when brand new which it still looks and drives like. Next service is EGR system for inspection and clean which based on IAC valve, I expect no surprises.
This is like being in a classroom at a technical college . Very informative.
great video! as a woman I'm so happy to say I fixed my car myself by watching this video!!
that's awesome! Thank you for watching and nice job on the fix
I don't have that expensive scanner, but found that there's 2 screws in the back of the IAC valve on my pickup I took it apart and as soon as I did you could here the rod inside move, when I put it back together and back on the vehicle it would idle smoothly. I tested the ohms across the IAC Valve and its within spec of 10-14ohms, but that don't mean the valve itself isn't stuck, so in my case taking it apart got the valve unstuck...the truck sat for 4 years, so its within reason the valve would be stuck I guess, ordered a replacement valve, but I bet if I had your scan tool I'd have some pretty similar issues that your scan tool was showing us.
This video was a great help. My truck wasn't doing the cold high idle either, it was probably down around 500rpm or so even cold, so that's most likely what got my attention at first was the weird low idle especially sense I have another truck with the same engine next to it that revs much higher when doing a cold startup.
Vehicle is a 1987 Ford Ranger 2.9L V6, and the other truck sitting next to it is a 1988 Ford Bronco 2 2.9L V6. Ironically I have 2 vehicles with the same engine, helped out with some diagnostic stuff being able to look around both vehicles and see what's out of place, and test parts to see what ohm readings I was getting on the known good vehicle VS the one that decided to go on vacation for 4 years LOL.
You are correct about a TPS voltage issue. It should be around .98 to 1.0 volts on all Fords I've ever seen. You had an initial hang up that was really high. But after the fix it was still 1.12v. Either somebody adjusted the idle stop screw up a bit to try and fix this idle issue, or more likely you have a dirty throttle body.
The IAC is designed to run in the middle of its range with the engine warm and AC off. Since its range is 20 to 60%, a 40% duty cycle would be about right. 35 to 40% with air off is good. This one is a little high despite a slightly high tps, possibly indicating a dirty IAC and/or throttle plate.
I have had some luck with cleaning the mechanical half of the valve. It's worth a try since the valve is 80 bucks.
omg i have a 2006 Chrysler pacifica i thought it was the transmission it would self acelerate and stall especially when i would turn ac on then i would turn on and it would shut down right after .tommorrow im gonna change the idle air controller your a life saver.
I was having this exact same problem on my 2002 Mercury Grand Maquis. I used my daughters cell phone to tap on the idle air conrol valve and this did the trick. Going to have a friend who is mechanically savvy clean it out for me. Thanks for this video!
Excellent information that explained on a higher technical level the I.A.C.V. operation. My Ford has hard cold starting, needs the throttle cracked open slightly, yet runs and idles perfectly off idle. I'm thinking sluggish solenoid when cold. Now I know how it all works. Thanks for posting.
This video is going to be referenced a lot for the Mazda community as well. I see a lot of people that complain of no-start unless the gas pedal is down. I always told people to start with a fuel pressure regulator diagnostic first. Didn't know the IAC would fail like this. Just learned an important lesson thank you!
Great video. Very informative for a novice / home mechanic like myself.
Thanks man. I'm from Brazil and here we don't have someone that explains abaut electric parts so good like you. Good job!
Thank you ! Very informative video, this helped me out with my 96 Lincoln town car 🚗
This video helped me fix my 2000 Mercury Grand Marquis with out throwing any extra parts at the car.Thanks ScannerDanner
when ya car got up to 10 mph did it bog down during the shift?
@@youngjj757 thats what mine is doin now
Had this issue at 80K took iac out cleaned it problem is back now....at 130K. I was afraid it might accelerate suddenly and potentially cause an accident but it's never done that (except once or twice which was my fault as the pedals are too far apart and not designed for tiny little feet like mine). I'm just grateful that mine didn't need to be included in the headlight recall. That's one thing I don't have to worry about going bad. I leave the heat off and I like it just fine. I also love how the electrics are super watertight unlike my Pontiac. I can just dump S100 on that motor and rinse it down with a pressure wand and get all that grime off so I don't have crud everywhere in my engine bay. Like a motorcycle or a semi truck just AWESOME!! I recommend you try it! Your brand loyalty will be insane and you'll buy another Ford.
Man, I am so sick of my crown vic not idling. it is always on the worst day. Its a guarantee that on a 0F day, when you want to let the car warm up outside, the car will not idle without my foot being there holding down the throttle. Well, its gotten worse in the past week.. You sir, have solved my problem with this video. a new ICV is on the way. Thanx for the hard work to make this great vid!
Thanks so much I've been working on my own car all my life 😊 However shit like the iac and other sensors irritates the shit outta me. I kinda figured this, but needed to know for sure the reason for my stalling. You're awesome very knowledgeable and I appreciate YOU!! Always looking to save money. Widower our here taking care of my business 💯😊
Sir your videos are awesome! your very talented in what you do. thank you for the information you provide, it helps me very much in learning how different components work. keep up the good work!
Thank you, this video literally saved my 2001 expedition. I just went with a replacement over the wrench tap though.
Great video; thank for the learning curve; just beating on things doesn't teach us anything; you are correct !!!
I might also add that it is educational to view the PIDs for TPS voltage, IAC duty cycle, Desired RPM, Engine RPM, and Mass Airflow while experimenting with adjusting the minimum airflow (idle speed) screw. This will teach you a lot about idle airflow. Idle airflow is made up of airflow that leaks by the throttle plate, and IAC airflow together. An increase in one results in a decrease in the other.
ScannerDanner knows wth he's doing 👍💪
Scanner Danner thank you for your time and help .
Based on a few videos of yours on this subject, my impression is that one of these 2 pin Ford / Mazda IAC valves can be defective, yet not cause a code, not fail a resistance test or show any issue on an oscilloscope, like the stuck closed valve in this video. Since the problem can't be directly detected, I'm assuming one has to go through a process eliminating every other possibility until nothing is left but the IAC? What is it exactly that causes these valves to get stuck like that? Carbon buildup or some other mechanical issue? I've read on a few Mazda forums of a problem in which these types of valves partially fail, i.e. the car starts, you get flair and extra air until the engine warms up, but once warm the idle is low, and if you put loads on the engine like the AC, high beams, or hold the break down in gear, the rpms will fall and the idle will get very rough, yet there won't be any codes and the IAC passes the WSM prescribed tests. Have you ever encountered this problem? What might be the underlying cause of such a problem. Sorry if this is too much for a youtube comment!
Carbon build up and a spring on the inside of it that fails. You can actually clean them and they will work
very interesting i have a 99 mazda v6 198,000 miles when ever i get to a red light. after 40 seconds my engine feels like a stallout but hangs... but with the foot on the gas its feel good. i will take the throttle body apart and clean the IAC and see what happens .....thank you for the informative video.
Good video my car would start when cold but really rough, replaced the IAC and problem solved thanks.
Hi, scannerDanner, I have a 97 legacy outback with 2.5. I am getting the same code P1507 as you discussed in one of your videos. I cleaned out the IAC and checked for air leaks with carb cleaner. Car idles well, however, check engine light is triggered after 5-10 minutes of driving. The car cuts out and restarts immediately. the resistance on the control valve connectors are 1-2 and 2-3 are 9.3 ohms off the car. I have tried to clean the throttle body but no change. Any suggestions? thx in advance
Great video I learned a lot. My nephew has 1994 Thunderbird a 3.8 V6 that he just bought from a friend of mine with 153K and he`s having the exact problem with the Idle.
+Mark Narretto thank you!
I have an 87 Ford econoline 302 and replaced the IAC but problem still exists. It starts fine and idles great till warmed up. Warmed up it idles fine in gear but as soon as it is placed in park/neutral it dies. I would bring it in to you but I am in Yuma Arizona. Any ideas?
OUTSTANDING Job Going through the process of Diagnosis on this matter.
Thanks, good video ! Having a huge problem with my Mustang 2004/ 3.8 litre ?? After changing fuel pump bigger, 255 lph, and throttle body to 70 mm, idle has been sky high?? I know there has to be vacuum leak somewhere, since AC works, and when blowing to face, suddenly changing to windshield, like defrost??, without touching anything??Codes are : P0507, and P0405?? Did change DPFE sensor ( tested it, fine!), TPS, IAC sensor, and EGR valve! Can't find any leaks under hood, sprayed all vacuum hoses?? Did check canister solenoid in rear, 12 V coming in, closes after applied 12 V??, did not change that?? No leaks around tank?/Did check canister purge valve in a front?? Could not test that?/, cleaned out, 12 V coming in?? Could that be open all the time, making idle that high??Did have " check engine light " on even before changing fuel pump and throttle body, every now and then, telling large vacuum leak, and " check fuel cap", did change fuel cap, no help?? Do I need smoke test next??? What could be reason for this leak/ high idle??? Going crazy here, thanks =) Ps. could there be a leak above fuel tank???
Dave, great video ! I watched the whole thing. Any suggestions would be greatly appreciated...
I have a 2004 Grand Marquis. Engine light came on last Sunday after I got gas. This week I had my mechanic check the car. He replaced the #5 coil and all plugs, even though previous plugs and coils had less than 11,000 miles. He cleaned and flushed out the throttle body and ran a computer electronic balance test.
I drive the car about 60 miles one week later (today) and stop at the same gas station, and when I start the car up, the engine light came on again. I reinstalled the gas cap, but no luck shutting the engine light off. Also checked the fuel send switch in the trunk, and it was not tripped. The symptoms I'm having are occasional rough acceleration from a dead stop, and occasional random momentary de-acceleration. The other symptom is that when I come to a red light, and the car has sat idling for about 45 seconds or more, the engine idle speed slows down and is noticeably rough. I plan to tell my mechanic what you did with the idle air control valve / motor.
Could that be my problem? Also, another video showed a "throttle position sensor" which some guy replaced on his C. Vic police interceptor. Should I replace that? The mileage on my car is 224,500. I am the original owner of this Marquis, and have changed oil religiously since purchasing the car. I also have changed the transmission fluid about every 40,000 miles. Thanks and hope to hear from you. Tom in Miami, FL
I have a 1989 5.8 . the engine starts and runs nice till it warms up. then the idle gets rough and will continue to run while more air gets drawn thru the iac valve then it idles up for a while and smooths out but will drop again. it just kinda plays that game. is their ever a time that the iac valve holes in the throttle body ever stop sucking air? like does the vale supposed to shut off that air flow or just restrict it?
My 96 Lincoln Town Car idles fine at startup; however, tends to stall at times when I put it on drive or when I stop at an intersection. Is that an IAC issue as well?
Sure sounds like it my friend. Does it ever stall while your foot is on the gas pedal? If no, and it only stalls when your foot is off the pedal, then we definitely want to focus on the IAC
@@ScannerDanner The last time I drove I took off after stopping at an intersection and with my foot on the pedal it felt like no fuel was going thru as I stepped on it more and then it stalled. Put it on neutral as car was rolling and started the engine back up.
@@Daluch3 focus on your throttle position sensor, these were common failures on your model and your symptoms sound more like this is where we need to focus
@@ScannerDanner I will certainly do that to start off and hopefully that's all it needs. Thank you!!
@@ScannerDanner Forgot to mention I checked the Check Engine light with a code reader and it shows the current fault as P0174 Powertrain System too Lean (Bank 2) and a Pending Fault P0171 Powertrain System too Lean (Bank 1). The PCV valve is brand new so I know that's not it.
I'm having problems with my 1999 Dodge Durango 5.2. My problem is that the vehicle has a hard time starting once warm than sits for a bit, I have to give it some throttle than fires up, runs fine. Fuel pressure seems to hold fine once turned off. Going to check out the IAC counts but not sure if it could be related. Maybe stays closed? but first start of the day etc.. starts right up no problem.
hey, its Rich, a former student of yours not too long ago. I have a mazda 6 at work. feels like it wants to stall at idle only. runs great while driving. never stalled on me. I think iac could be bad. m not sure where to check next. no codes
enjoyed the video, like always and thanks. you stressed concerns about TP voltage that someone may have adjusted the idle stop. did you address that issue? do you think the voltage was a bit high? are you thinking buildup in the throttle body may be the reason? thanks.
I have problem with my 2000 Ford Focus. Just replaced the TPS and now the car revs up so high on idle and the engine light came back on. You think smacking the IAC will help?
Interesting- does simply giving it a love tap have good long term success?
You Guy's are awesome i have a 98 crown vic mine has the issue when its cold outside keeps stalling unless i hold throttle a little for about 5-10 mins then runs great will these act up more when its cold outside thanks from Joe!
yes, very possible
Hello, I have a 2003 Ford Expedition 4.6 v8. The vehicle idles at around 1200 rpm in park and neutral. When i put it in reverse or drive it idles fine. The main problem i am having is that the lights will go bright then dim and the vehicle will die and i will lose power steering and brakes. It starts back up in park immediately, I dont know if it is relevant to the probem but it seems like after it rains it always has electrical issues, all the dash lights come on and pulsate and still drives fine. Any information would be appreciated ScannerDanner!
How do you differentiate between a bad IAC and a dirty throttle body? Won’t in both cases they have high IAC counts that doesn’t allow vehicle to idle?
I've got an 01 expedition that hasn't idled right since I replaced the intake gasket. It does the flare up that you speak of, then drops pretty low, then planes out just a little lower than what I think it should be. It stalls every now and then but not always. There is a code, I forget what the number is but it basically says that it's idling to low to properly run all the accessories. Any input would be great.
I installed a new IAC on my ford truck because the old one was stuck shut now the new one stays open all the time could it be coolant temp.
YOU ARE THE GREATEST OF ALL TIME😃
I have a 97 Ford F-250 5.8L that does this same thing. However, whenever I unplugged one of the vacuum lines, it starts right up (doesn’t idle perfectly) and still tries to stall whenever I try driving it above 30mph. It ran fine before and just started this recently.
Can the IAC be cleaned with an appropriate aerosol and if yes what product would applied? Thank you
Never had luck cleaning the Ford IAC valves
Sir could you make a video dealing with the 2001 grand marquis MAP sensor test. Thanks in advance
I have some Ford MAP sensor videos. They have digital output unlike every other manufacturer lol
good day sir
what scanner/diagnostic tool did you use with a oscilloscope...
I have a 2006 Mazda 6 and it does that but when you press on the gas the whole car shakes and it stalls, do you know what the problem is?
Hi, I wanted to ask a question regarding the operation of IACV. I know that at start up, IACV is fully opened by ECU to help in starting and that it is opened during decelaration with throttle closed to ensure smooth running of engine. Should the IACV (stepper motor type) be open when the throttle is open (partially or fully)? With engine cold and hot. I noticed that my IACV (stepper type) does not fully close even when throttle is opened at least with cold engine. Its not for a specific vehicle but I have a pre-OBD-2 vehicle (European) of Renault.
scannerDanner....i have a 2003 mach 1 that's giving hinging idle issues..the revesre of what thus video concludes I guess. have u encountered this issue, any help would be appreciated. tps is non adjustable on this year but when I disconnect it the idle is normal
This reminds me of your Lexus RX300 video :) Great video!
Love your videos, it makes me a better tech everyday
Nice ! I've got a 94 3vzfe that won't start cold with out pedal. Idles at 4 to 500 hot.
You can actually clean a sticking IAC with carburetor cleaner if you don't want to replace it.
When they run rough, then die, will I see the duty-cycle % drop? Because the valve has carbon deposits in it and cannot maintain correct duty-cycle? It is hot weather here so on mine I find that with AC on, it increases duty-cycle enough to prevent stalling : )
You see how hard this is for me to follow? It really helps me to stay in the same thread. You have some really good questions here
Great video I have a '93 Grand marquis 4.6, it will stall and hesitate and surge, usually stall if you give it too much gas. Feels like a miss going down the road you can feel it bucking slightly. Can't figure it out! New MAF and intermittent check engine light. Please help!
Not enough info to help you, sorry. What code is setting? When did the problem start? Have you tested fuel pressure?
Your problem could be withing the fuel system, ignition system, or even engine mechanical.
ScannerDanner hey I just checked fuel pressure it's barely 20PSI supposed to be 35-40 I think I found my problem
Yes you did my friend. Nice job
What if the flare up upon cold start, starts off too high like 2200-2500 and then drops to about 1500 when engine is cold. Is the IAC bad? What does this say about the IAC? What causes it to cold start too high? Drops down fine after to 800 RPM when warm.
Once they get stuck cleaning may be a bandaid fix. Worn out will come back later just replace it. Good fix to tap if stranded.
wow!!, i couldnt believe that this actually worked. i got my wife to hold the gas
while i taped the housing with vice grips and the engine reved up and the
car idled on its own.
Nice!
@@ScannerDanner That is exactly what I did to my starter before I replace it.I suggest to just replace that dar n thing.
I sure wish I could bring my dead 95 Mark VIII to have you diagnose it! It's been dead since January 2018. 😭 I just can't bear to part with it though, keep thinking I'm going to fix it one of these days. 😒😔
Can the idle air control valve become stuck open and cause a vacuum leak?
yes
2005 pt cruiser gt stalls and then starts after setting iac code 508 O2 codes 32,38. It wont run when i unplug the IAC it stall. I bleave that the curcit is good. If it runs with the sensor plug in. And the AIC must be sticking. Or cant keep up with the PCM. And its giving the O2 sensors the high voltage.
Hi , I have an 86 f150 and have added a Innovate MTX-L wideband , mine is doing the same thing , whats happening is the mixture starts off ok for a cold engine then it gets richer and richer as the motor warms up , it does the rolling surge and dies when it hits 10.9:1 , as someone mentioned maybe the CTS sensor maybe telling the computer its a cold engine ? or the IAC is doing weird things and giving engine less air .
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15 minutes ago
My 03 f150 stalls out but ONLY when in park and after it warms up, which definitely leads me to believe it’s the IAC. Starts and drives just fine, and doesn’t idle rough when in gear (every once in a while at a stop light it acts up but has never stalled). Think it’s getting pretty dirty especially given it has probably never been replaced in the last 16 years. Guess I’ll give it a go. Didn’t throw a code
Hi Paul, A query please. I just fixed a stuck Idle Speed Actuator Control on a Hyundai Accent 2004, with open-close bi-solenoid PWM control (not a stepper) and MAP engine. It was stuck partly open with a 1500rpm idle speed. Sounds simple. What threw was the code p0121 TPS/APP range performance not p0507 idle too high. I also had a Desired Idle Speed on 1500rpm, oddly, rather than normal 750rpm. I suspected the ISA but the odd code and DESRPM made me spend time eliminating the TPS/APP before attacking the ISA. It cleaned up and works fine. But here's my question: why a DESRPM of 1500?? After the fix the DESRPM is normal. My explanation: MAP engine detects low Man Pressure, ECU desires higher idle RPM as a result, like a cold engine?? Maybe it desires the higher RPM, but senses a range performance from a closed RPM/throttle plate and APP at normal idle??
I don't have answer for you on the desired idle number. A TPS problem would definitely cause what you are describing.
MAP signal wouldn't be the answer as manifold vacuum at 1500 is typically identical to idle speed.
I've never seen a sticking IAC valve (open) cause a desired idle command to increase
I have a 2009 Altima. It will start just fine but will stall out when placed in gear. If I give it yes immediately after placing it in gear it will drive fine but will stall again at stops unless I put it in neutral. Amy ideas?
Gas immediately*
In all honesty, If I was a gambling man, this vehicle probably has ignition coil issues but we do not 'change parts purely on speculation' Awesome job yet again Paul, there always has to be a plan B if plan A fails. Ah, and do not worrying about the camera work, it is the content that matters.
2;/17/2021 I did not get a reply from Scanner Dave. However this video is as good as you will find on Marquis & Crown Vic idle and acceleration problems. Here's what I suggest anyone should do who has a Crown Vic or Marquis from the late 1990s to 2011 models with idle & acceleration problems. IF changing coils and plugs did not solve the problem, then do not hesitate to change both the throttle position sensor and the air intake control valve. (I have a 2004 Marquis). The throttle position sensor is $36.00 at Auto Zone, part #TPS245. The air intake control valve (also called a Throttle Air Bypass Valve), part #TV2004, cost is $75.00. Replace these two parts, BEFORE spending a lot more on a new fuel pump and installation. These two parts may solve your problem entirely if your plugs and coils are working correctly.
Also check the connections to all 8 coils to make sure the coils are properly connected. One loose coil connection can trigger the engine light, and create idle and acceleration problems. Ebay has the same parts mentioned above, but made by different manufacturers for less money if you don't have much to spend. The other things you may need to have done is to have the throttle body assembly cleaned out, and the air intake sensor cleaned. There are youtube videos that show how to clean the air intake sensor. I tried cleaning my own air intake sensor, which is close to the air filter. Cleaning it did not work. The air intake sensor is a different part than the two parts mentioned above, located inside the air duct tube by the air filter. You should see an electrical connection for this part on top of the air duct tube.
2/20/2021 update. Unfortunately, I drove the car this weekend after replacing the parts mentioned above.
I noticed the same thing started happening after I drove about 20 miles. One thing I noticed under the hood is that (standing in front of the car, the coil closest to me on the right) the front right coil is loose, very sloppy. I will have the mechanic check it and update this post. I tried pushing in down onto the spark plug, but it's still very loose.
I'm still interested in seeing what % the iac valve would of had if u simply cleaned it??????
Ikr seeing how the part almost predominately works on airflow I would have just cleaned it first
Any idea why the PCM does not monitor the iac to trigger a check eng. light. For a novice a MIL would have helped .
Because, this type of IAC does not incorporate a position sensor.
I personally don't know of any IAC devices that incorporate a position sensor other than electronic throttle control systems. Stepper motor IAC don't have position sensors, but the PCM knows the position of it because it counts steps to get to the desired RPM. Some vehicles have software that will set idle speed low codes and some don't. This Merc doesn't, but it will set an idle air control system malfunction code (P0505) if you run the KOER test.
IAC's, and all types of solenoids, are feed-forward devices. Meaning the computer tells the solenoid what to do, and expects that it did it. There is no feedback directly from the device. In this case, it isn't necessary, as the computer knows what RPM it is commanding, and via the crank sensor it knows what RPM it achieved. Typically, a code can be set if the engine RPM is not able to be controlled.
Thank u keep doing it the long way I'm learning
Anyway i can send you a video of my 4.6 and how it idles. Havent found a video that sounds like it .
cool video i will try this my iac is stuck all the way out,but ill replace it.thanks
I have a 1996 Lincoln Town Car:
What if I have this exact problem but with an error code of P0125? Notice that the car won't start unless foot is on the gas pedal. Happens only during the winter; would have to wait till car warms up a bit before it will stay on. The other day no matter how long I let the car warm up with my foot on the pedal it didn't stay on (happen on a 20F day with snow), had to adjust the idle speed. Is it the same cause?
ProfounDisputes According to what I'm seeing, it's "insufficient coolant temperature for closed loop fuel control". My first thought is that the thermostat is stuck open, so the engine never comes up to full operating temp. The plus is that it's a quick, cheap fix, but there are people on here who know far more than I do.
I have a 1999 Ford explorer it idles then shortly after of I'm backing up it'll stall then I noticed the oils gauge jumps as well o did some research but Idk what it is any help
What if your problem is when it's cold out it won't idle and run have to keep giving it gas and keeps starting and keep starting it and after that at idle and run fine when the temperatures are warm like 55 or something and to start out with no problem and run but when it gets cold I have a hard time getting it to start to have to crank it 20 30 times and then finally she'll start and run you think that's the idle control valve?
If it is an idle control valve issue, it will run perfectly fine with a slight throttle opening. If you are having trouble keeping it running with a steady light throttle opening, it is NOT an idle control valve issue
My 2008 crown vic seems to run ok but randomly will die at idle. It always starts right up afterwards. It was happening about once a month but seems to be happening more frequently. Could it be the IAC?
Your 2008 is probably an electronic throttle control system and there is no IAC valve. I would perform a throttle cleaning procedure first.
love it how he explains detail
I have ford expedition 2003 i make smoke test with ciggarret and i see leak smoke in iac cup part is normal or is broke the part
Normal. That is a bleed port open to the atmosphere.
my vx commodore 2001 in Australia it has rough idle or it seems to idle low to me, it does not stall but sometimes at trafic lights it will idle perfect, I am thinking the iac is not opening enough to let enough air in, when the car is going it is very good it is just idling low, what would be your say on this, when it idles good that tells me there are no air leaks and the injectors are good, I dont have any DTC and no engine light
Clean the throttle body before you do anything else
Mine won’t idle in cold weather. Soon as it’s warm it idles fine. Is this the same issue?
Absolutely can be, yes
My car is a 09 Chrysler 300 3.5 getting code fuel to leqn bank 1&2 or something like that. A light comes on 2 lines and a red lighting bolt when I drive it drives fine but when I go to stop or completely stop light comes on along with my slide control warning light and it shakes a bit and dies or stalls bad thinking it's a bad egr but sprayed it didn't look dirty u think it's my iac?
No, you don't have one, it's an electronic throttle body. Sounds like a vacuum leak. Do a keyword search "water test" on my channel where I teach you how to locate them.
So I changed my IAC and TPS on my bronco. when it starts up it flares up then idles down to normal. But after I drive it or tap the throttle and let off it stays idling high in park and neutral. What could it be? I have also changed my vacuum lines and air filter.
Monitor TPS voltage and make sure it is returning to the closed throttle value
@@ScannerDanner It doesn't. I have changed it with a new part and it does the same thing. Changed the IACV also. I am starting to think it could be my throttle body. I am going to try to pick a used one up at a salvage yard and see if that fixes my issue.
Edmonton, Alberta, CanadaHave a 2003 Taurus 3.0 OHV....been having stalling and fast idle issues.speed will increase on it own. when stopped or in park If i turn on the air or the heater on DEF setting the RPM will fluctuate up and down then car will stall out.have checked for vacuum leaks and it seems ok
ok. im dealing with a 2003 ford taurus vín number 2 so itsthe ses model 3.0. iac throws i code to the obd 2 intermitantly. iac. pissed a voltmetter test and visual test. it dirty. but not bad. my problém is if u snad the thottle the engine will die out. and it will surge under a normal dříve. ideas?
hi i have a 2005 mercury mariner, the vehicle will sometimes run great then if im just in park it will die.had it scanned mechanic said was the fuel pump i replaced it and still acts up. watched your video on returnless systems so replaced fpdm. still acted up. well sometimes run 20 min or so fine and just idles down tell it dies and no help putting foot on gas pedal. starts right back up then does the same thing. if left for awhile it will crank and run fine then might act up never know. im in need of help scannerdanner.
When it dies are you losing fuel pressure? If so, you need to do some voltage measurements at the FPDM when it is NOT starting
@@ScannerDanner yes starts again but dies. Yesterday cleaned the grounds at pcm and fpdm after running half hour it died and sit the lean codes and for the fuel rail pressure sensor. This was replaced when I first got it back in August. Can I check the wires at fpdm with a multimeter and if so what should it read
In a previous video you said that the TP(V) should be below or around 1.0V. Here it is 1.14V . Is that normal?
It is a little high but is a non issue in this case. Ford TPS idle readings are higher than most cars.
yeah i thought so thanks i have a gmc 1500 slt big muffler 2 pipes gion in one coming out can i cut the muffler of and run staight pipe out would it make a diffence besides being louder
I would like to see a sample of what is a good waveform instead of looking at just voltages. I would like to see a bad and a good waveform sample.
GOLD STANDARD, GREAT STUFF.
Would I be able to read this data with a global scan tool?
My ford will drop the idle almost stalling the car when I'm slowing down or stopping for red lights in neutral/with the clutch in, the revs usually drop and rise 2-3 times before sitting stable.
I suspect the IAC needs a replace but checking the data over like this would make me alot less anxious dropping money on a new part.
Clean your throttle body first!
@@ScannerDanner Thanks man, it wasn't very dirty but it definitely improved after cleaning.
I still do get an idle drop sometimes but its only significant when I've got a bunch accessories on (heater/fan + headlights but not AC(AC seems to fix it).
Any idea where I can look next?
IAC does work properly from what I've tested unless its just reacting slow for some reason.
Turning the wheels while braking also makes the idle drop worse (only in neutral/clutch in again)
If you had an improvement with cleaning the throttle body, you may have a sluggish IAC valve. I hate to tell you to change it based on that alone.
What is your idle speed with the IAC valve unplugged? It should just barely idle 400 rpm roughly
@@ScannerDanner it just stalls right away, with IAC plugged in it sits around 700
What year, make, model and engine?
Have you adjusted the minimum idle speed? In other words, does it look like anyone has ever messed with the base idle set screw?
th-cam.com/video/ayjhL9jpFH8/w-d-xo.html
I have an 02 sable that is doing this. I have already changed the IAC as well as the egr pressure sensor and solenoid. They were melted. Car still will not run without your foot on the pedal. Any suggestions. Also the iac is getting power.
Vacuum leak
use my water test
David Pritchard catalytic converter is plugged up. Had the same issue on my ranger. Melted egr pressure sensor and hoses. I actually blew my air tube going to the egr too.
great i have 03 cv great advice also can you tell me will it make a differnce if i put cold air intake after i put a new iac thanks great advice
Arthur Metcalfe don't bother. these "cold air intakes" are nothing but a gimmick . your factory air box is NOT a restriction. In fact most of them draw underhood "hot air" after installing them. Completely defeating the whole purpose.
Are the duty cycle to percentage open numbers on Mazda's similar to those on Fords? As in 20% is closed, 30% no load idle and 50-60% fully open? When I read IAC% in a scan tool like ForScan, is that telling me duty cycle or actual percentage open?
I think they are similar.
You are looking at the duty cycle NOT percentage of valve opening. Great question!
Hello. I know its an old video but I want to ask if bad idle control valve does effect engine while driving? I have no codes and I know valve has to be changed and Im waiting for one to come very soon but when Im driving I feel hits from the engine. Spark plugs are new. Ignition coils checked.
No, if your foot is on the gas pedal and you are having running issues it will NOT be from the IAC valve
@@ScannerDanner Thanks. Then I have to search more. May be mass air flow then.
Haha you said doodie!! J/k nice video. Should help a lot of people considering how many IAC valve issues on Fords you see in the field!
Mine 2004 Town Car IAC went bad. Instead of putting the foot on the pedal it actually accelerate without the foot on the pedal. It can actually drive on its own by just steering and braking tho it would burn the brakes and stress out the transmission. Mechanic simply replace the IAC valve and runs back to normal. No problem since than. But is weird how IAC valve works
Counts are the older steeper motor set ups if I'm not mistaken.