Thank you. My 87 k10 has been fighting me for a couple of years, replaced the 02 sensor a few years ago and didn't think it was causing the problem that you just showed me
Currently running the o2 in the manifold on my 93, But unplugged, and it solved my surging idle and rpm drop when turning the wheels at a stop. Gonna replace it tomorrow more than likely, as well as plugs because it was running super rich, Probably fouled those.
This is pretty similar to what mine is doing. Same year, same engine. It runs okay-ish until operating temperature. Once it reaches operating temp, it really starts to struggle and dies pretty fast.
My 91 has been running this way shortly after I changed my starter it started has progressively gotten worse I've changed alot of parts on it and nothing found out how to read the OBD1 using a paperclip came up code 13 so I bought an O2 sensor today going to change it in the morning really hoping it solves the issue glad I came across this video as well it gives me a better feeling about going this route thanks for the info will let you know if it fixes it
I had similar problem on my first 92 Chevy it was fuel pump. they say electronic fuel pump's don't go on and off they do trust me. but every problem has about 20 different solution's lol
I've had the same problem with fuel pumps working then not working. Sometimes banging on the gas tank will get a none working fuel pump to start spinning.
+Wicked Spray you are correct wicked spray. but I have learned allot about these 90's rides like a rock truck.LoL. but im still learning more and more. after 15years of 5 different stiles they all have the same quarks low miles not nesaseraly a good thing. more miles means most crap has been taking care of lol
Two things I replaced that were causing similar issues in two separate instances. First time fuel pump was going out. 2nd time lots of surging and would kill at idle ended up being o2 sensor.... shit was seized on. Had to cut it off and weld a new piece on.
My truck is doing the same exact thing. Unplug the 02 and it runs fine. Got a new 02 put it in and still surges when it's plugged in. Runs fine unplugged.
Probably a ground problem. The o2 grounds through the exhaust which tends to get rusty. Loosen up the o2, strip the end off some wire, wrap it around the threads and tighten it back down. Now run that wire to a good ground. See if that fixes it.
I have a '93 C1500. It came with a 4.3. Now has a 5.7. I'm still using the old O2 sensor set up but the EGR system is bypassed. Everything else is stock. I have a surging idle after warm up at stop lights 550-700 rpm; idles at 1000 in neutral usually but will drop to 800 given enough time. PS: how did you get those readings from the OBDI connection?
James Bobo it's not hard to understand the O2 sensor ideally should read .500 volts anything above that means your rich so the ecu will pull back fuel below that your lean so the ecu will add fuel, if you had a scan tool you can see this as a percentage. That's just the simple jist of it there's more to it but you can find out if your O2 sensor is bad with just that info.
yes, the engine was running very lean due to having the wrong injectors in it. it had v6 injectors which flow less than v8 injectors..@@jaysonsmith3614
Wicked intent❤️❤️❤️😇🤝 ! I have a 1987 Chevy g20 van , when I stop and go at times it acts like it surges low and seems to ( want to cut off) but when I give it gas it operates normal. When cruising it vibrates smoothly like it’s trying to shut off. Everything’s new on it( did it myself) distributor, coil pack, distributor ( didn’t set timing yet) by ear, new tank fuel filter, alternator everything. What could be my problem? 🤝🤝🤝😇?
Hate to chime in so late. Check the Idle Control Adjustment Valve. Its another electronic piece of needless crap on the 90's trucks. I had a bad "Z" block in my 94 sport side Sierra. I swapped an "A" block into its place from a 91 S10. My truck did the same thing with the swapped motor. Idle Control Adjustment Valve was the problem and is on passenger side of throttle body. Again...its electronic...it is crap...and goes bad. It was intended to fine tune in real-time the idle of the engine at different temps and altitudes. It is completely separate from the actual idle adjustment screw on the driver side front end of throttle body. When this ICAV goes bad it either stays way open or way closed. This will cause fuel to run rich or lean. Procedure for replacement is online. You can't just plug and play. You have to install the valve then jump two pins at obd to "re learn" the valve. At the same time you must find actual idle screw on opposite side and adjust idle to 600 rpm. Unplug jumper at pins and the engine should then be running like a top.
I've replaced my IAC and still have this problem. But I also forgot to do that learning process. When it started it was at 2k rpms. I will try the relearn process
I noticed the rpm spike when the surge happened. Is it possible the crank sensor may be shorting or losing connection? Usually after warm up a faulty crank sensor will start malfunctioning. If it’s going bad the symptoms will get worse. The other place I would be looking is at the distributor, especially if it’s an HEI ignition. Keep up the good work Ivan
Good morning I've got a 93 Chevy 1500 with a sbc 5.7 and it will not run right at all I've changed everything in it including the the electrics in the distributor too no avail .what else is there to check . I've replaced the all the solenoids sencers pick up coil throttle body ECT...... I have no code's c poping up it runs great cold but once it's warmed up it run like do do like there's only 4 cilinders oh and I put a new o2 cencer in it also . HELP PLEASE I don't know what else to do........ Steve
94 Chevy gets code 13, changed 02 and check light came right back. idles good, runs good but hits high gear and power lose, have to gas it and it takes off. cruising speed is very week. any ideas?
my 92 astro check engine comes and and off all the time but runs great..check your fuel pressure ...could have dying pump and fuel filter clog. check the basics first.
So I took to O2 sensor out and it instantly sounded better. Drove it around and then sat in a parking lot waiting on a buddy to get off work for nearly 25 minutes and it had a perfect idle. Baught a new O2 sensor today and slapped it in there and it started loping like that about 30 seconds after I cranked it up for the first time after I put the new O2 sensor on. And it's still running super rich, I can smell it come out of the exhaust. Suggestions?
Hi My Nephew has a 1991 Chevy K1500 gasoline engine. It shakes at idle and the oil pressure drops when he makes any kind of turn. Struggles to make 40mph. I told him to check for plugs, points (if it has them?), engine oil level, engine mounts. I think they are giving up on it but I think it could be sorted out and it has huge sentimental value cause it belonged to his grandfather. Any ideas I dont really know too much just know what I dont know which is alot
Hey Joey, I got an obd1 to usb cable and plug it to my old laptop. You can use tuner pro rt or there are some other free programs you can get. Still troubleshooting my 89.
My 94 Chevy suburban surges when I’m at a red light and slowly take off, also when I turn into a street going slow it surges to but don’t turn off the rpm just goes back up by it self. Anyone know what’s wrong?
my temp sensor ohms at 5.4 on the 200 k scale cold, and 0.9 hot .. truck is idling badly. when it warms up it runs better, but like its stuck on high idle/
thanks for the comment. it ended up being a bad o2 sensor. I didn't explain it well in this video but i have a link in the description for a video showing the outcome.
I have 1997 silverado z71 i put a cheap code reader on it in it came up with po303 and 02 sensor bank 1 and 2 and its idles at 1000 rpms at start then slowly goes down to 600 rpms after running for awhile any advice? Its a vortec 350 btw aswell
P0303 is the code for a misfire on cylinder #3. Does the engine have a misfire? The Idle should be higher at start up and come down once warmed up, nothing wrong there. Check cylinder #3 spark plug and make sure it's sparking.
Wicked Spray there brand new spark plugs when i rev it really high sometimes it will i have fuel line leak btw aswell and sometimes itll tick but then when its warmed up it stops
I have a 94 suburban Silverado edition TBI 5.7 I have replaced every sensor you can think of full tune up complete with I still have a low idle surging shaking no check engine light to speak of put a new muffler on it seemed to get worse new battery alternator new belts pulleys fuel filter I'm at loss the only sensor I have not replaced the O2 sensor I unplugged the O2 sensor it seemed to run better but my idle still stayed at a 100 rpm?? I guess what I'm asking if I replace O2 sensor with my idle go up
Mine is idle surgeing like that and new iac is letting air out making a loud air sound. I bought new o2 sensor no chang. When I disconnect o2 it doesn't go into a loop check engine light doesn't come on in park. The only time it sort of straightens out is when I disconnect the map. I've thrown every sensor at this thing changed distributor, fuel puump its been a pain 😆
I have a 92 C1500 with 5.0 engine, and TBI, 5 Speed manual, 2wd, will start and stall when cold, once warmed up, its fine. New Coolant Temp sensor, complete tune up, new fuel pump and gas tank, new IAC valve, no codes and no service engine soon light. Also, I had to disconnect the EGR Valve vacuum line or the truck will constantly run and shut off. With this line disconnected, the truck runs good when warm. Any thoughts you can offer about this problem will be greatly appreciated! Thank you!
I have a problem with mine that it spit and sputter then once it get about 180 200 temp it runs fine I changed the spark plugs the distributor cap is new the wires are kinds new. I tested fuel pressure it's low but I wouldn't understand y it get better once it warms up if it was a fuel pump. I tried the o2 sensors thing and it still was the same so Idk
I'm kinda having the same problem..... I'm "running" from what I was told a 90 Camaro 5.7 TBI with cast heads with about 100k on motor. And a 90s ECU for management from aperently a 90s Chey truck!!..this is what I was told!!! But egr is deleted as well as heater core and all vacuum hoses. I'm Running a t56 transmission as well.....NOW THIS "SWAP" is in my 92 Nissan 240sx. Lol. So everything is okay I guess but power is garbage dyno at 184 hp and 270 ft lbs I'm running a walbro 255 fuel pump for fuel delivery. And my O2 sensor is garbage and just zip tied to the side of fire wall haven't made a bung in my down pipe yet.. but really shouldn't cause it to idle and die. None the less here's the problem. When starting the car/motor I have to constantly keep the revs/rpm at about 1000 rpm.. if not motor wants to "TRY" and run at 400 to 600 rpm and stall/die. Drove it at a DRIFT event a few weeks ago.. and was really honestly trying to blow motor so I can put another 350 in it. But NO GO. Full cast iron motor/heads aperently hard to blow up. Lol But motor/car would still runs fine after beating the ever Living shit out of it. But when coming back around to start line it would want to stall. Same as driving in the street I have to heal/toe= drive with heal on throttle and toe on brake..or vice versa depending on how you drive to keep revs/rpms up. Haven't really had time to track down the problem because I work a lot but this week I picked up a summit/ Holly 650cfm dubble pump carberator!! Probably too small for what I want to do. But I also picked up an elderbrock high performance intake for the carberator going to throw it on the motor with a HEI distributor to gain my damn HP back. but it's still cold here in GA and need a good daily driver so this is gonna be my daily for a bit. And don't want to install carberator/ intake/ HEI just yet because the TBI is more reliable as a daily driver..... But I need to figure out idle/stall issue on the motor before I start driving it about 500+ miles a week for the next few weeks... I know the IACV An TPS could cause these problems I'm having.. but everything it's all okay I've checked resistance and voltage on both and installed new just incase an still same issue. the only thing I might think it could be is that my alternator is only producing about 11 to 12 volts at a low idle "below1500 rpms" and then upon running above 1500 RPM it will do about 13 to 14 volts but that's just my voltmeter that I have inside on the dash so whether or not that's a hundred percent is I don't know... As I said will run.. an run fine but letting off throttle and trying to get it to idle on it's own it just wants to stall and die now I am running a smaller alternator off a John Deere diesel tractor from the 1950s but it's able to produce enough amperage and voltage be able to continue running the motor find the battery has been relocated to the rear of the car using 0 gauge wire... I am running a front plate Mount on the motor and a trans mount only no motor mounts but also having charging issues. Will post video later. Altenator is rewired as a single wire with internal regulator I have grounds from chassis to motor but it's a damn headache. I honestly do not know what stock/standard proper fuel pressure is susposed to be ran on 5.7tbi.
james wilson is the o2 wiring connected to the o2? If so try disconnecting it and see if it runs better. Also check for vacuum leaks and intake leaks. That will make it idle rough and stall but run better at higher rpms.
My 93 Silverado 5.7 tbi is doing the same thing. I have tried tracing another weird problem with the pump (buzzing) staying on even after turning off the truck by key.. unplugging the battery is a pain in the ass all the time. Anybody know what it could be? Bad pump is only thing I can think. Thanks.
So my 1994 Suburban does the same thing. The difference is it has a cat delete. No sensor even hooked up. What could be the problem for me? You say by disconnecting the O2sensor fixed your problem but without on at all what would cause these same symptoms?
Are you sure the front o2 isn't hooked up? If they didn't put a cat in I would think they would unhook the rear o2 but not the front. I'm asking because you say it runs good cold. The computer doesn't use data from the front o2 when cold, only after warm up. When starting cold the computer uses pre-set perimeters for fuel mixture until the coolant temp and the o2 heaters are warmed up.
I only have the one pigtail for the front O2 sensor, no rear sensor plug anywhere. if it matters its a 3 inch exhaust that both come to the passenger side and join prior to the first O2 sensor.
front O2 sensor is still hooked up and in place. even the dealers said no rear O2 sensor... why would you have an upstream but no down stream sensor..... doesn't make sense to me.
The truck is older so it doesn't monitor the cat efficiency, that would be why it has no rear o2. So I'm confused here, first you said the front o2 isn't hooked up but in your last reply you say it is hooked up and in place. Can you get access to a scanner to see what the computer is showing for o2 activity? If the front o2 is connected and in the exhaust try running a ground wire from the metal part of the o2 to a clean ground on the engine block (or negative cable on the battery). Those trucks use 3 wire o2 sensors and ground through the exhaust which gets rusty and not supplying a good ground.
Hi i need help I have a 1992 Chevy silverdo it runs good when the motor is cold but once it starts to heat up running temp it starts to drop the rpms low when I'm at a stop light or sign I have to put it in a neutral and press the gas a bit so it won't turn off
John Morales...my 94 does the exact same thing...have replaced every sensor....fuel pump...filter ..timed right...yet when it is warm....the rpms drop and surges along with the oil pressure...lmk if u figure yours out .
@@t.b.y.3350 I wish I would help but same here I changed Evey sensor new distributor fuel pump and filler timed it and nothing I still have the same problem and I took it to 4 mechanics and they all tell me it's fine I'm getting to the point where I wanna sell it already
Check coolant temp sensor, if its bad it shuts the fuel circuit off. this circuit also runs thru your oil pressure sensor. check these before replacing high dollar fuel parts.
I put a new fuel pump, and did the same thing, pulled it all apart changed the lil hose and clamps to metal hose clamps make Shurr all o rings are in place ,I was missing an o ring, now runs strong
My 92 chevy silverado kind of acts like this at idle... check engine come on only at the idle as well. Very strange and it was my daily driver now im scrambling to find something else
I’ve been tracking and driving that idle stumble for 50k at least I’ve done everything I know she runs fine just had a slight gas smell and stumble at idle. One day I’ll figure it out
hey Wicked Spray i have a 1993 cheyenne doing the same thing. ive replaced every sensor and electrical part under the hood with no luck. but my O2 sensor you mentioned isnt attached to my exhaust. its just hanging next to it(when i had exhaust repaired they used a straight pipe without the O2 port. could this be my problem? according to this video i can unplug it and remove it all together and my truck will run ok? thanks for the video and any info you can provide. been trying to get this truck running right for over a year. dont want to scrap it over something small i just cant figure out.
Is the 02 sensor still connected to the wiring or is the 02 sensor missing? If it's still connected that very well could be your problem. What happens is if the 02 sensor is disconnected from the wiring harness the computer can detect that and reverts back to factory settings for fuel delivery. This will usually keep the engine running and run half ass descent. If the o2 sensor is still connected this will cause the computer to get a false reading and seriously lean out the fuel trim, remove it and see if that makes a difference. Other problems could be a bad distributor cap/rotor, bad plugs/wires, fuel pump, bad vacuum leak(especially the brake booster), bad map sensor or timing off.
Wicked Spray thanks for the reply. Yes the O2 sensor is still connected. I’ve replaced the plugs. Wires. Map sensor. Cap rotor and that plug on the distributor. Checked the vacuum on the hoses. I feel like the only things left are the fuel pump and distributer. I’ve tested the fuel pressure tho and it seems to be fine. I’ll unhook the O2 sensor tomorrow and let you know if it helps. Thanks for the info.
Wicked Spray i have a 95 runs a little better than the one in the video. Its throwing a code 32 and 44 egr valve and lean mixture. Disconnected the egr and o2 sensor no change still stumbles and dies. Just started this yesterday a few hours into a 200 mile trip after filling up with high test gas. Any ideas would be greatly appreciated.
Wesley Cooper An Actron CP9690 code tester checks record, graphing, live, smog test readiness test, oil light reset, and MORE! It has OBDI cables for Ford, G.M., Chrysler, and 2 Toyota. The CP9680 only does OBDII.
@@randy1ization damnit dude I've replaced so many parts I'm ready to give up! I doubt it's my injectors I have spares and when I switched them out. It's still the same!
@@chastblind7606 u need to get an OBD1 tool to see whats going on. if u are sure u have no vacuum leaks, and are using high quality parts is important too.. lots of cheap junk that doersnt work right out of the box, what exactly is your truck doing? what year is it?
@@randy1ization i've replaced IAC, map, spark computer thing, EGR valve solenoid, TPS, fuel pump relay and rebuilt the TBI. I do have the EGR valve O2s and temp sensor on order. The truck will try to die sometimes after I put it in drive/reverse my idle is somewhat okay. It will die sometimes. Idk after all this I just might do fuel pump and screen last. I've replaced almost everything at this point
Yes you can run it without the O2"s hooked up but the performance will suffer, plus if you have cats installed it could melt/clog them if it's running rich.
What this truck needs is a trip to the junkyard LOL you got the computers hooked up trying to solve problems and figure out why it runs like shit I’ll tell you why it runs like shit because it’s 30 fucking years old and worn out anybody that spends more money than an air filter and a set of spark plugs on one of these is kidding them self
Wicked Spray: Yes, but if you watch the Scanner it's jumping in and out of, open and closed loop. Wasn't sure if that was normal? Sorry for not being more clear on my question.
Thank you. My 87 k10 has been fighting me for a couple of years, replaced the 02 sensor a few years ago and didn't think it was causing the problem that you just showed me
Just wanted to say thanks. I had the exact issues with my 91. Tried unplugging the O2. Runs fine. Bought a new O2 sensor and problem fixed.
Thanks for that info.
Where exactly is the 02 sensor located on these engines?
@@almaricky1driver side by the header
Currently running the o2 in the manifold on my 93, But unplugged, and it solved my surging idle and rpm drop when turning the wheels at a stop. Gonna replace it tomorrow more than likely, as well as plugs because it was running super rich, Probably fouled those.
Thanks Brother! That was the most beneficial help I’ve gotten from TH-cam and quite some time I appreciate you Posting this video. Sincerely Rob c
Please tell me you're being sarcastic.....
This is pretty similar to what mine is doing. Same year, same engine. It runs okay-ish until operating temperature. Once it reaches operating temp, it really starts to struggle and dies pretty fast.
What did you do to fix it
@@meawesomemax3947 I sold it
@@philconey11 lol damn I was hoping for a "mechanical fix" =)
Dang mine is in the same boat; but no live scan
@@meawesomemax3947 im having the same issue from a bad exhaust leak and the upstreem o2 sensor being in the wrong spot
My 91 has been running this way shortly after I changed my starter it started has progressively gotten worse I've changed alot of parts on it and nothing found out how to read the OBD1 using a paperclip came up code 13 so I bought an O2 sensor today going to change it in the morning really hoping it solves the issue glad I came across this video as well it gives me a better feeling about going this route thanks for the info will let you know if it fixes it
any update ?
@@HOTRODRICO I got rid of it a couple months ago
@@fiscalgoose7664 so it didn’t fix it?
Had similar issues on my '92 -350 Replaced o2 sensor,AIC sensor and Map sensor ,did great things and gained 4 mpg to boot.
it kinda sounds like a snowmobile lol miint two stroke dude!
I had similar problem on my first 92 Chevy it was fuel pump. they say electronic fuel pump's don't go on and off they do trust me. but every problem has about 20 different solution's lol
I've had the same problem with fuel pumps working then not working. Sometimes banging on the gas tank will get a none working fuel pump to start spinning.
+Wicked Spray you are correct wicked spray. but I have learned allot about these 90's rides like a rock truck.LoL. but im still learning more and more. after 15years of 5 different stiles they all have the same quarks low miles not nesaseraly a good thing. more miles means most crap has been taking care of lol
@@wickedspray7475 why o2 sensor did u happen to unplug by chance we have a 89 chevy 2500 and its cutting out and cant fig it out.
Two things I replaced that were causing similar issues in two separate instances. First time fuel pump was going out. 2nd time lots of surging and would kill at idle ended up being o2 sensor.... shit was seized on. Had to cut it off and weld a new piece on.
Idle control valve 9 out of 10. Do oxygen first cheeper.
My truck is doing the same exact thing. Unplug the 02 and it runs fine. Got a new 02 put it in and still surges when it's plugged in. Runs fine unplugged.
Probably a ground problem. The o2 grounds through the exhaust which tends to get rusty. Loosen up the o2, strip the end off some wire, wrap it around the threads and tighten it back down. Now run that wire to a good ground. See if that fixes it.
I have an isuzu rodeo 1992 3.1 tbi and mine idles good but at lower rpm start surging the rpm over 2k rpm works well
I have a '93 C1500. It came with a 4.3. Now has a 5.7. I'm still using the old O2 sensor set up but the EGR system is bypassed. Everything else is stock. I have a surging idle after warm up at stop lights 550-700 rpm; idles at 1000 in neutral usually but will drop to 800 given enough time. PS: how did you get those readings from the OBDI connection?
Any updates? I have the same issue
OMG I got to take some college classes to understand this guy
James Bobo it's not hard to understand the O2 sensor ideally should read .500 volts anything above that means your rich so the ecu will pull back fuel below that your lean so the ecu will add fuel, if you had a scan tool you can see this as a percentage. That's just the simple jist of it there's more to it but you can find out if your O2 sensor is bad with just that info.
what will make these trucks go into a looping surge on start up when cold, then go away when warm.
Did u ever figure it out
yes, the engine was running very lean due to having the wrong injectors in it. it had v6 injectors which flow less than v8 injectors..@@jaysonsmith3614
Wicked intent❤️❤️❤️😇🤝 ! I have a 1987 Chevy g20 van , when I stop and go at times it acts like it surges low and seems to ( want to cut off) but when I give it gas it operates normal. When cruising it vibrates smoothly like it’s trying to shut off. Everything’s new on it( did it myself) distributor, coil pack, distributor ( didn’t set timing yet) by ear, new tank fuel filter, alternator everything. What could be my problem? 🤝🤝🤝😇?
same shit here , revs dies revs dies ... nonpowes smells like shit ... replacing parts now and still pos idle 🤬🤬🤬
Hate to chime in so late. Check the Idle Control Adjustment Valve. Its another electronic piece of needless crap on the 90's trucks. I had a bad "Z" block in my 94 sport side Sierra. I swapped an "A" block into its place from a 91 S10. My truck did the same thing with the swapped motor. Idle Control Adjustment Valve was the problem and is on passenger side of throttle body. Again...its electronic...it is crap...and goes bad. It was intended to fine tune in real-time the idle of the engine at different temps and altitudes. It is completely separate from the actual idle adjustment screw on the driver side front end of throttle body. When this ICAV goes bad it either stays way open or way closed. This will cause fuel to run rich or lean. Procedure for replacement is online. You can't just plug and play. You have to install the valve then jump two pins at obd to "re learn" the valve. At the same time you must find actual idle screw on opposite side and adjust idle to 600 rpm. Unplug jumper at pins and the engine should then be running like a top.
I've replaced my IAC and still have this problem. But I also forgot to do that learning process. When it started it was at 2k rpms. I will try the relearn process
You ever check the EGR valve, the diaphragm might be most up and is putting to much oxygen in there
lol he's literally explaining what the exact problem is. it's not the egr.
Idc what anybody says I've had 3 truck with the egr thrown out, my current truck doesnt have an egr they run just fine without the egr system,
EGR does not inject oxygen it ,it injects exhaust into the cylinders -EGR-Exhaust Gas Reserculation
I noticed the rpm spike when the surge happened. Is it possible the crank sensor may be shorting or losing connection? Usually after warm up a faulty crank sensor will start malfunctioning. If it’s going bad the symptoms will get worse. The other place I would be looking is at the distributor, especially if it’s an HEI ignition. Keep up the good work Ivan
Tbi doesn't have a crank sensor.
@@jnotah It does, driver side
@@HOTRODRICO No. 1987-1995 GM tbi doesn't use a crank sensor. I have used this on other engines to convert to fuel injection.
@@jnotah I think you're right, I may have been thinking of the knock sensor...
Thank you for the help and great info !
unplug all of them??
Dang u just saved me so much $$$$$ I was wanting what it was now I fixed it thank and what kind of scan to u got ? Would love to get one like this
If I left the o2 in plugged but I have no cat. What would happen
Mice.
I've had a crazy fuel pump that was in and out do the same exact thing before! Then it finally died!
I can see that happening because it boils down to a lean fuel condition
@@randy1ization gm trucks are basically junk. ive got a 2009 now problems problems all the time i just dont get gm at all?? they use to be good.
Can this be the reason why my truck stalls out when coming to a stop ?
I have a 93 with the 5.7 it idles rough until warm then after about 1 min it runs smoothly any ideas i have changed temp and IAC as well as plugs.
Good morning I've got a 93 Chevy 1500 with a sbc 5.7 and it will not run right at all I've changed everything in it including the the electrics in the distributor too no avail .what else is there to check . I've replaced the all the solenoids sencers pick up coil throttle body ECT...... I have no code's c poping up it runs great cold but once it's warmed up it run like do do like there's only 4 cilinders oh and I put a new o2 cencer in it also .
HELP PLEASE I don't know what else to do........ Steve
94 Chevy gets code 13, changed 02 and check light came right back. idles good, runs good but hits high gear and power lose, have to gas it and it takes off. cruising speed is very week. any ideas?
my 92 astro check engine comes and and off all the time but runs great..check your fuel pressure ...could have dying pump and fuel filter clog. check the basics first.
What is the most likely cause of a 32 code in these? No other codes present and no noticeable difference in operation.
EGR valve
Mine ran fine without an o2 Sensor my problem was my temp sensor on the front of the intake, I replaced both temp and o2
The exhaust donut sounds like it's leaking, that causes a false reading to the 02, as too much of the exhaust is not making it to the sensor.
Is this true? I think mine is leaking and I’m having a low idle stumble then it’ll buck off I floor it
@@SirGuidemere91 that is the problem I'm having below 2k rpm is sluggish then smooths out..... any luck figuring out?
@@freemanfornow264 the pigtail connectors on mine were busted causing a throttle issue
@@SirGuidemere91 pigtail connectors on what? The 02 sensor?
@@freemanfornow264 idle air control valve and the map sensor. I did clean the throttle body when in replaced them as well
i got a 93 burban doing the exact same thing
So I took to O2 sensor out and it instantly sounded better. Drove it around and then sat in a parking lot waiting on a buddy to get off work for nearly 25 minutes and it had a perfect idle. Baught a new O2 sensor today and slapped it in there and it started loping like that about 30 seconds after I cranked it up for the first time after I put the new O2 sensor on. And it's still running super rich, I can smell it come out of the exhaust. Suggestions?
Bad wiring,ecm, or new sensor wrong or defective
Hi
My Nephew has a 1991 Chevy K1500 gasoline engine.
It shakes at idle and the oil pressure drops when he makes any kind of turn.
Struggles to make 40mph.
I told him to check for plugs, points (if it has them?), engine oil level, engine mounts.
I think they are giving up on it but I think it could be sorted out and it has huge sentimental value cause it belonged to his grandfather.
Any ideas I dont really know too much just know what I dont know which is alot
What are you using to read live data for the OBD1 style? I have a 92 Chevy G20 TBI and I would love to get live data from the engine
Hey Joey, I got an obd1 to usb cable and plug it to my old laptop. You can use tuner pro rt or there are some other free programs you can get. Still troubleshooting my 89.
I have a 99 silverado with the 5.3 that does the idleing issue, doesnt have the clancking noise tho, any idea
My 94 Chevy suburban surges when I’m at a red light and slowly take off, also when I turn into a street going slow it surges to but don’t turn off the rpm just goes back up by it self. Anyone know what’s wrong?
Did u figure it out mines doing the same thing
Have yall figured it out?
It's just got a big cam lol.
I appreciate it
my temp sensor ohms at 5.4 on the 200 k scale cold, and 0.9 hot .. truck is idling badly. when it warms up it runs better, but like its stuck on high idle/
Check the distributor cap and rotor button may be causing a misfire.
thanks for the comment. it ended up being a bad o2 sensor. I didn't explain it well in this video but i have a link in the description for a video showing the outcome.
I have 1997 silverado z71 i put a cheap code reader on it in it came up with po303 and 02 sensor bank 1 and 2 and its idles at 1000 rpms at start then slowly goes down to 600 rpms after running for awhile any advice? Its a vortec 350 btw aswell
P0303 is the code for a misfire on cylinder #3. Does the engine have a misfire? The Idle should be higher at start up and come down once warmed up, nothing wrong there. Check cylinder #3 spark plug and make sure it's sparking.
Wicked Spray there brand new spark plugs when i rev it really high sometimes it will i have fuel line leak btw aswell and sometimes itll tick but then when its warmed up it stops
Does it throw a xode for a o2 sensor and if so whats the code
I have a 94 suburban Silverado edition TBI 5.7 I have replaced every sensor you can think of full tune up complete with I still have a low idle surging shaking no check engine light to speak of put a new muffler on it seemed to get worse new battery alternator new belts pulleys fuel filter I'm at loss the only sensor I have not replaced the O2 sensor I unplugged the O2 sensor it seemed to run better but my idle still stayed at a 100 rpm?? I guess what I'm asking if I replace O2 sensor with my idle go up
Check for plugged cat or egr valve, also check fuel psi, 10psi minimum
@@Dave-lg5oz you know it was a failing brake booster
@@worstnightmare9772 brake booster caused low idle?
Mine inly does it at idle
Hey man I was just curious how we're you able to read diagnostics with modern scaner?
The snap on scanner will do obd1 with an adapter cable
Ok thank you
Mine is idle surgeing like that and new iac is letting air out making a loud air sound. I bought new o2 sensor no chang. When I disconnect o2 it doesn't go into a loop check engine light doesn't come on in park. The only time it sort of straightens out is when I disconnect the map. I've thrown every sensor at this thing changed distributor, fuel puump its been a pain 😆
I have a 92 C1500 with 5.0 engine, and TBI, 5
Speed manual, 2wd, will start and stall when cold, once warmed up, its fine. New Coolant Temp sensor, complete tune up, new fuel pump and gas tank, new IAC valve, no codes and no service engine soon light. Also, I had to disconnect the EGR Valve vacuum line or the truck will constantly run and shut off. With this line disconnected, the truck runs good when warm. Any thoughts you can offer about this problem will be greatly appreciated! Thank you!
D J Tanner check for a vacuum leak. check the egr valve, make sure it's not stuck open.
The knock sensor is bad.
Charles Matthews , knock sensor, really?
No. It is not a knock sensor. O2 needs replaced.
D J Tanner 0
I have a problem with mine that it spit and sputter then once it get about 180 200 temp it runs fine I changed the spark plugs the distributor cap is new the wires are kinds new. I tested fuel pressure it's low but I wouldn't understand y it get better once it warms up if it was a fuel pump. I tried the o2 sensors thing and it still was the same so Idk
Woolen Ominvore did you ever get it fixed?
Will this cause transmission to shift funny as well?
Yes
my 1998 Chevy Silverado 5.7 has the same problem all 02 sensors went bad so it idles rough but when i give it gas no problem
you have obd2 ..you can get live data from that..find someone with a good scan tool.
I'm kinda having the same problem..... I'm "running" from what I was told a 90 Camaro 5.7 TBI with cast heads with about 100k on motor. And a 90s ECU for management from aperently a 90s Chey truck!!..this is what I was told!!! But egr is deleted as well as heater core and all vacuum hoses. I'm Running a t56 transmission as well.....NOW THIS "SWAP" is in my 92 Nissan 240sx. Lol. So everything is okay I guess but power is garbage dyno at 184 hp and 270 ft lbs I'm running a walbro 255 fuel pump for fuel delivery. And my O2 sensor is garbage and just zip tied to the side of fire wall haven't made a bung in my down pipe yet.. but really shouldn't cause it to idle and die. None the less here's the problem. When starting the car/motor I have to constantly keep the revs/rpm at about 1000 rpm.. if not motor wants to "TRY" and run at 400 to 600 rpm and stall/die. Drove it at a DRIFT event a few weeks ago.. and was really honestly trying to blow motor so I can put another 350 in it. But NO GO. Full cast iron motor/heads aperently hard to blow up. Lol But motor/car would still runs fine after beating the ever Living shit out of it. But when coming back around to start line it would want to stall. Same as driving in the street I have to heal/toe= drive with heal on throttle and toe on brake..or vice versa depending on how you drive to keep revs/rpms up. Haven't really had time to track down the problem because I work a lot but this week I picked up a summit/ Holly 650cfm dubble pump carberator!! Probably too small for what I want to do. But I also picked up an elderbrock high performance intake for the carberator going to throw it on the motor with a HEI distributor to gain my damn HP back. but it's still cold here in GA and need a good daily driver so this is gonna be my daily for a bit. And don't want to install carberator/ intake/ HEI just yet because the TBI is more reliable as a daily driver..... But I need to figure out idle/stall issue on the motor before I start driving it about 500+ miles a week for the next few weeks... I know the IACV An TPS could cause these problems I'm having.. but everything it's all okay I've checked resistance and voltage on both and installed new just incase an still same issue. the only thing I might think it could be is that my alternator is only producing about 11 to 12 volts at a low idle "below1500 rpms" and then upon running above 1500 RPM it will do about 13 to 14 volts but that's just my voltmeter that I have inside on the dash so whether or not that's a hundred percent is I don't know... As I said will run.. an run fine but letting off throttle and trying to get it to idle on it's own it just wants to stall and die now I am running a smaller alternator off a John Deere diesel tractor from the 1950s but it's able to produce enough amperage and voltage be able to continue running the motor find the battery has been relocated to the rear of the car using 0 gauge wire... I am running a front plate Mount on the motor and a trans mount only no motor mounts but also having charging issues. Will post video later. Altenator is rewired as a single wire with internal regulator I have grounds from chassis to motor but it's a damn headache. I honestly do not know what stock/standard proper fuel pressure is susposed to be ran on 5.7tbi.
james wilson is the o2 wiring connected to the o2? If so try disconnecting it and see if it runs better. Also check for vacuum leaks and intake leaks. That will make it idle rough and stall but run better at higher rpms.
Wicked Spray yes O2 is connected will try unplugging it when I get home.
9-13 psi
My 93 Silverado 5.7 tbi is doing the same thing. I have tried tracing another weird problem with the pump (buzzing) staying on even after turning off the truck by key.. unplugging the battery is a pain in the ass all the time. Anybody know what it could be? Bad pump is only thing I can think. Thanks.
OIL PRESSURE SWITCH
Oil psi switch or stuck fuel pump relay, the are typed into the same power wire to fuel pump
So my 1994 Suburban does the same thing. The difference is it has a cat delete. No sensor even hooked up. What could be the problem for me? You say by disconnecting the O2sensor fixed your problem but without on at all what would cause these same symptoms?
Edit... it only happens when warmed up, when cold it runs great.
Are you sure the front o2 isn't hooked up? If they didn't put a cat in I would think they would unhook the rear o2 but not the front. I'm asking because you say it runs good cold. The computer doesn't use data from the front o2 when cold, only after warm up. When starting cold the computer uses pre-set perimeters for fuel mixture until the coolant temp and the o2 heaters are warmed up.
I only have the one pigtail for the front O2 sensor, no rear sensor plug anywhere. if it matters its a 3 inch exhaust that both come to the passenger side and join prior to the first O2 sensor.
front O2 sensor is still hooked up and in place. even the dealers said no rear O2 sensor... why would you have an upstream but no down stream sensor..... doesn't make sense to me.
The truck is older so it doesn't monitor the cat efficiency, that would be why it has no rear o2. So I'm confused here, first you said the front o2 isn't hooked up but in your last reply you say it is hooked up and in place. Can you get access to a scanner to see what the computer is showing for o2 activity? If the front o2 is connected and in the exhaust try running a ground wire from the metal part of the o2 to a clean ground on the engine block (or negative cable on the battery). Those trucks use 3 wire o2 sensors and ground through the exhaust which gets rusty and not supplying a good ground.
awesome video thank you very helpful
Hi i need help I have a 1992 Chevy silverdo it runs good when the motor is cold but once it starts to heat up running temp it starts to drop the rpms low when I'm at a stop light or sign I have to put it in a neutral and press the gas a bit so it won't turn off
John Morales...my 94 does the exact same thing...have replaced every sensor....fuel pump...filter ..timed right...yet when it is warm....the rpms drop and surges along with the oil pressure...lmk if u figure yours out .
@@t.b.y.3350 I wish I would help but same here I changed Evey sensor new distributor fuel pump and filler timed it and nothing I still have the same problem and I took it to 4 mechanics and they all tell me it's fine I'm getting to the point where I wanna sell it already
check for vacuum leaks. Try pinching off the big vacuum line to the brake booster and see if that helps.
@@wickedspray7475 i just disconnected it and it sounded much better do think it will be better to change the whole brake booster ? Thank you so much
@@wickedspray7475 update i just put a new brake booster and its doing the same thing as the other one when i take off the vacum line. Plz help
what happens if just leave o2 unplugged
texas tough it’ll probaly run very bad
@@TheUndertoe It will just jump to closed loop (based on chip.) Mine ran just fine with no O2 sensor plugged in.
i got a 98 chevy tahoe new fuel pump and filter starts but wont stay running please help
Aaron Kincaid problem is your egr
EGR
Check coolant temp sensor, if its bad it shuts the fuel circuit off. this circuit also runs thru your oil pressure sensor. check these before replacing high dollar fuel parts.
I put a new fuel pump, and did the same thing, pulled it all apart changed the lil hose and clamps to metal hose clamps make Shurr all o rings are in place ,I was missing an o ring, now runs strong
I have this same problem and it wasn't my O2 sensor. Another other ideas?
with out seeing the truck maybe fuel pressure, a spark problem, vacuum leak, timing, engine coolant temp problem, map sensor just to name a few.
Wicked Spray MAP sensor
Just leave the O2 sensor un-plugged,,,,,, job finished. Move on to next car
Mine does this and I've already changed the oxygen sensor I have a one wire 92 c1500 runs fine idols like crap
Check the throttle position sensor
Replaced O2 twice not O2 sensor
93 chevy is surging badly unplugged the o2 it didnt change anything any ideas
Iac
My 95 Chevy Tahoe 1500 does that it'll act like it's running outta gas
It also backfires
Brandon Yoder
Ignition coil
My 92 chevy silverado kind of acts like this at idle... check engine come on only at the idle as well. Very strange and it was my daily driver now im scrambling to find something else
Vanessa Centers did you find out what was wrong
I’ve been tracking and driving that idle stumble for 50k at least I’ve done everything I know she runs fine just had a slight gas smell and stumble at idle. One day I’ll figure it out
I would've appreciated if you would've showed the sensor & also where was located
+ggg's fan the front o2 sensor is located in the exhaust pipe under the truck just before the exhaust heads up into the engine compartment.
Wicked Spray thanks 👍
no problem. This was my first vid. I'll make sure to show locations better in future ones
I have this problem before I saw this video and replaced my O2 sensor and I still have this problem so this didn't fix my issue
Try looking at the throttle position sensor
@@johnwayne8178 I got one yesterday. Also I'm going to be replacing the fuel pump relay
@@brettbeez I was reading your post, so is your truck fixed?
@@robertoleeva985 my issue was a bad fuel pump. Once i replaced it the issues stopped. The old pump was running hot and inefficient
what is the scan tool you are using
john plushy Snap On Modus Ultra.
I have a 88 Chevrolet Silverado with 5.7 only cuts out after warmed up. Its not o2 sensors. Any ideas
Ignition control module
If it was ICM it wouldn’t even crank
hey Wicked Spray i have a 1993 cheyenne doing the same thing. ive replaced every sensor and electrical part under the hood with no luck. but my O2 sensor you mentioned isnt attached to my exhaust. its just hanging next to it(when i had exhaust repaired they used a straight pipe without the O2 port. could this be my problem? according to this video i can unplug it and remove it all together and my truck will run ok? thanks for the video and any info you can provide. been trying to get this truck running right for over a year. dont want to scrap it over something small i just cant figure out.
Is the 02 sensor still connected to the wiring or is the 02 sensor missing? If it's still connected that very well could be your problem. What happens is if the 02 sensor is disconnected from the wiring harness the computer can detect that and reverts back to factory settings for fuel delivery. This will usually keep the engine running and run half ass descent. If the o2 sensor is still connected this will cause the computer to get a false reading and seriously lean out the fuel trim, remove it and see if that makes a difference. Other problems could be a bad distributor cap/rotor, bad plugs/wires, fuel pump, bad vacuum leak(especially the brake booster), bad map sensor or timing off.
Wicked Spray thanks for the reply. Yes the O2 sensor is still connected. I’ve replaced the plugs. Wires. Map sensor. Cap rotor and that plug on the distributor. Checked the vacuum on the hoses. I feel like the only things left are the fuel pump and distributer. I’ve tested the fuel pressure tho and it seems to be fine. I’ll unhook the O2 sensor tomorrow and let you know if it helps. Thanks for the info.
so whY was wrong with it
vince flores bad o2 sensor.
The knock sensor $50-$80
Charles Matthews it wasn't a knock sensor.
Wicked Spray i have a 95 runs a little better than the one in the video. Its throwing a code 32 and 44 egr valve and lean mixture. Disconnected the egr and o2 sensor no change still stumbles and dies. Just started this yesterday a few hours into a 200 mile trip after filling up with high test gas. Any ideas would be greatly appreciated.
Wesley Cooper An Actron CP9690 code tester checks record, graphing, live, smog test readiness test, oil light reset, and MORE! It has OBDI cables for Ford, G.M., Chrysler, and 2 Toyota. The CP9680 only does OBDII.
is it the same on single wire pre exhaust chevys, if I unplug it and it stops surging its an o2 issue
Was it an o2?
@@chastblind7606 no it had the wrong size fuel injectors in it
@@randy1ization damnit dude I've replaced so many parts I'm ready to give up! I doubt it's my injectors I have spares and when I switched them out. It's still the same!
@@chastblind7606 u need to get an OBD1 tool to see whats going on. if u are sure u have no vacuum leaks, and are using high quality parts is important too.. lots of cheap junk that doersnt work right out of the box, what exactly is your truck doing? what year is it?
@@randy1ization i've replaced IAC, map, spark computer thing, EGR valve solenoid, TPS, fuel pump relay and rebuilt the TBI. I do have the EGR valve O2s and temp sensor on order. The truck will try to die sometimes after I put it in drive/reverse my idle is somewhat okay. It will die sometimes. Idk after all this I just might do fuel pump and screen last. I've replaced almost everything at this point
I unplugged the 02 sensor and it got worse, would hardly run
I finally figured it out. it had 4.3 liter injectors in it. . its a 5.7...
Can you run it without the O2 sensor?
Yes you can run it without the O2"s hooked up but the performance will suffer, plus if you have cats installed it could melt/clog them if it's running rich.
Nobody watch this video for any other information than where the sensor is all of that nonsense is for no reason and a waste of our time
Talks a lot.... Don't say much.
What this truck needs is a trip to the junkyard LOL you got the computers hooked up trying to solve problems and figure out why it runs like shit I’ll tell you why it runs like shit because it’s 30 fucking years old and worn out anybody that spends more money than an air filter and a set of spark plugs on one of these is kidding them self
Lmao just because you dont know your asshole from your elbow dont mean you deserve a trip to the junkyard
What a joke these things don’t quit age is just a plus least you know they’ll last 30 years
Any reason why it goes from open to closed loop?
It goes to closed loop when the engine temperature and the 02 sensor warm up.
Wicked Spray: Yes, but if you watch the Scanner it's jumping in and out of, open and closed loop. Wasn't sure if that was normal? Sorry for not being more clear on my question.