This is a 1991 GM TBI system. I know it is old and we don't see many of these systems anymore, but the fundamentals still apply to ALL fuel pump and fuel delivery designs. From the mechanical return type, to mechanical return-less (regulator in the tank), to electronic return-less (no regulator) systems. Even the low pressure, delivery side, of today's GDI systems! Fundamentals my friends, they do not change and this video will be valuable information for troubleshooting all of these systems. Sure there are some minor differences in testing, depending on the fuel delivery design, but the core of this is the same! What is covered in this video: 1. How to identify a lean condition 2. Visual spray pattern test of a TBI injector 3. Using the oxygen sensor to ID a fuel delivery problem 4. Measuring fuel psi on a return type system 5. How to check fuel pump max psi (dead-head test) 6. Fuel pump power and ground testing 7. Fuel pump current and RPM measurements 8. How to ID a good ground on your meter 9. Fuel pump motor disassembly to show brushes and commutators 10. Discussion of testing for bleed down issues
I’ve been waiting on this video for 2 years. I’ve had troubles ever since my filter was clogged. Many thanks for the video. You provided details that others glossed over or didn’t show. 1995 K1500 TBI here. Your doing some good in this world in many ways.
Hey scannerdanner! Last week our van broke down and we just so happened to breakdown next to you and you ended up saving our church van from a rats nest in a part of the engine, we got down safely and had an incredible time and I wanted to say thank you once again for helping us!
This meeting was ordained by God, no doubt in my mind. I can't stop smiling every time I think about it. I got to see some of the worship on some FB posts and I would have loved to have been there with you guys for that! This entire thing felt like I got to meet part of an extended family that I didn't even know that I had. Pray for me to be a light in the darkness as I will do the same for you.
I couldn’t believe it when I seen it! I just removed my neighbor’s fuel pump in his 1991 GMC Sierra TBI. I watched your video and did my testing the best I could with just my multi meter. I determined it was the fuel pump since I do have voltage with a load and a solid ground at the pump and no fuel pressure at all. My filter was restricted but not blocked but figured the pump went out because of the restriction (old age). I tilted the bed and removed the pump and took a look at it afterwards and I couldn’t believe that mines had a crack (tear) in the exact spot as the one in your video! The exact same truck, make and model. I watch videos to get myself familiarized before I start and see what I might run into since my mechanic days are over for me because of my age (70). The symptoms I had are exactly like yours in the beginning of this video. Engine starts but won’t stay running and can’t increase RPM’s, falls flat on its face in a second or two. Would run if spray carb cleaner into the throttle body. As soon as I seen the tear in my pump, I remembered this video and had a good laugh that is had the exact same problem. I’m lucky here in Hawaii as our vehicles aren’t rusty underneath, all of my fasteners were easy to remove with minimal rust. Thanks for the video and tips which made my experience in fixing my fuel problem easier to resolve.
Such a coincidence) I just replaced weak old 17 years old Fuel Pump on my Nissan Titan. All troubleshooting was done according to your book! God Bless You!
What a thorough breakdown. This diagnostic process eliminates variables one by one and helps to ensure the correct course of action is the final decision. An hour of diag time is worth three hours of needless parts shotgunning. Well done Danner as always. Watching you and your brother cut up is a bonus.
Good find! Shout out to the owner that keeps the truck in such a nice shape! Also, Ivan had something similar on "Eurotrash" last episode where a plastic line got disconnected internally. But first he had to undo all the other stuff people had doing beforehand to even be able to diagnose it, was quite a case.
My dad owned a 90 chevy van that had that same TBI setup. It was the first fuel injection setup I ever worked on. It is real easy to work on and fixed compared to todays F.I. setups.
Okay now that I watched this and slacked off enough this morning it's back to your lectures on the Verus scan tool. The one I bought came with the board and I can follow your class along. Lecture 12 here I come.
That "hose" isn't really a hose. It's thicker and called a pulsator. It's supposed to smooth out any pulses in the fuel delivery. A new one is supposed to come in the box with the new fuel pump. Can't ignore changing that part. Great video with lots of useful information.
@@joe1273 I know the part you are speaking of, however some were just a piece of hose about twice as thick as fuel hose only without braiding. It served the same purpose as the metal one. Nonetheless my point was a new one comes in the box for a reason, and should not be ignored when changing the fuel pump. If the pump had been recently changed, as Paul suspected, the changer screwed up by leaving the old one in. I've been ASE certified since it started in 1975 and know what I'm talking about.
I have ran into this problem before. The deadhead test showing zero pressure increase was your clue that the coupler hose at the pump was leaking. Even a weak pump would have shown some increase in pressure if that coupler hose was good. Thank you for another awesome video.
The deadhead test did not reveal anything to us beyond a weak pump. If a pump cannot reach fuel psi regulated psi (13 in this case), it is essentially running under a deadhead condition already. The regulator remained completely closed, no different than my pliers did. Make sense?
@@ScannerDanner OK So in this system had you only replaced the hose the pressure may have increased but until it surpassed the regulated pressure there would be no pressure increase with a deadhead test. And of course if it did get up to specified pressure there would be no issue. Got it and thanks again for everything you and your son do for this industry.
I’m in Texas. My Family has 3 TBI Trucks. & I get a Lot of OBS customers. I just put the adapter in place of the Filter. Plus I have a working Red Brick. They also blow out the fuel hose between the pump & strainer that can throw you for a loop. My truck is a 88 C3500 tbi 454
You guys really earn your money. Explanations very thorough so even a newbie can almost keep up. Would love to drive to you but I can't even drive in my drive let alone to the US. My car (2006 Opel Tigra Twintop) starts fine but cuts out after 10 secs. Fuel tank 1/4 full -- so at least the sender in the new pump I fitted is working. Under advice of those who know more than me, I changed the fuel filter, the fuel pump (nightmare); no difference. As for the regulator, mine is within the fuel pump assembly, fitted to and part of the whole fuel pump assembly and not sold as a separate item. I have a Schrader valve on the fuel rail to take a pressure tester but 99% of kits don't have the appropriate fitting... go figure. One is arriving Monday that is supposed to have such a fitting. If I hear the click from the rear when turning key to position 2 (1 being just pushing it in) that means electrics are fine, right? ... Or having seen your vid I'd better see if I can check the wiring plug going into the pump. Have a cheap Obd2 tool but that's not showing any codes; would buy even up to 200 dollar one if it would find the fault but have spent much time reading up on them and they all have a considerable number of detractors -- 10% of 45,000 ratings puts me off. Any advice please anyone. I see you have a vid on that so will look at it... Thanks again for your work. I don't want to be a mechanic, just be my mechanic.
You only need to ask this question once. 3rd time I'm seeing it on various videos this morning. It gets confusing for me to follow. Reply only to my last question. Not here
Mechanics even ask me: "Why do you buy expensive scanners?" and then answer the question themselves saying because "it tells you everything". I wonder how are they mechanics when they don't understand a tool that is so important in this industry. A lot of mechanics only think that a mechanical tool to replace parts is all they need.
Haha these videos with ur brother in the back ground either eaten or singing is hilarious always good to see videos like this and especially on older vehicles . But i had a 88 S10 2.5 5speed an it did this issue an worse on turns an so i had a idea to fill the tank up or put more gas in it an sure enough that's exactly what was wrong the hose inside the tank for the fuel pump had a hole in it and when I had a full tank it would run good . An then I started to hear the fuel pump spraying inside the tank from that hose being bad so I knew for sure that's what had happend .
My 89 c2500 fuel pump did the same thing. It had a split in the rubber hose. It had a full tank of gas so I did not want to drop the tank. I removed bolts that hold the bed on except the last two on the back and left them real loose. I tilted the bed up and changed the pump.
Hi Paul I am a retired mechanic in Dover England,in 1990 i had a fuel problem that only happened when I road test the car up a steep hill,it turned out to be a split pipe like the one in your video.it was on a Vauxhall cavalier the only time in 50 years of working on cars.look up jubilee way Dover England to see the White Cliffs of Dover bridge that helped find the fault cheers
Thank you for another perfect video!!! It is very fun to watch you and your brother together. I'm disapointed you don't have more likes but I hope you enjoy making video with your brother. Caleb shoud be showing more in the video too. Watching your videos is a job for me but it's also fun. Everyone watching yours and suchlike videos must be in love with this job.
20 years ago, one of those TBI systems kicked my butt. Rubber hose inside tank was split like that one. Special rubber hose is required for submersed fuel line. If you don't use that, it degrades and blow a hole in it.
been there done that, replaced many of them that dry-rotted and split. a tell tale sign is listening to the fuel filler with cap off and tank less than 1/4 filled, it sounds like a waterfall inside when running or key turning to prime the system or powered with test connector. make sure it's submersible rated fuel hose/section and it's always a great idea to replace the pump and strainer screen while at it! I got bit by that a few times.
Now we have learned why not to be a parts changer. Paul learned the hard way just like most live decisions as we all have,hopefully that is lol. Ending was awesome! I just did a fuel pump well just the hose..owner said he just replaced it with a oem. All symptoms just like this one lead to fuel pump, turned out he replaced the pump but didn't use the proper line ( external rubber fuel line) not knowing about fuel line for internal use. Always great content danners. Be well guys!
love your videos...been reading your book...but I had the same problem with my mom 98 chevy tahoe 5.7 vortec...i usually change it out myself but my mom needed it change out since it was boggy so she took it to shop...ran good for a week or so then same thing...bought new pump and drop tank...same thing cut in hose and clamps fell off...those cheap plastic ones...install some spring clamps replaced hose...didnt even replace pump and returned after a month...been running perfect for 3 years...now im working on my 95 tbi this what brought me here...trying to figure out my problem
Love these trucks! I just bought a 93 K2500 and learning about TBI through doing! Thought at first it was carbureted and I was like "Uhhh are those injectors in the throttle body?!"
Always a great video Paul. Thanks for your time. Now wouldn’t checking pump rpm show how the hose is split and causing the “overrunning” speed of the pump, like being out of gas? The ones I’ve had the current is low, rpm is high is usually a good clue of out of gas or split hose in tank.
it wasn't much lower, not enough for me to even think along these lines my friend. 3 amps before, 4 amps after the fix, and only about 600 rpm difference too
Hey Paul it's Bruce again thanks for showing me that 91 I have a 1992 Chevrolet c1500 with a TBI on it my friend had that same problem but he didn't let me get to the fuel system before he started changing a whole bunch of stuff and by that point it was screwed so thanks for showing me that as soon as I get some money I go back to work I'm going to be getting on your your scanner dinner premium web page website with TH-cam and I'll be ordering your your books I want to take your class so I'll see you in a few weeks
Nice find. I had a 1997 miata recently that had a brand new pump fitted less than a year before it came to me on a hook with no fuel pressure. I'm scratching my head at my fuel pressure gauge and had to go straight to the pump outlet at the tank. No pressure. Pull the pump. Split hose. BUT. I discovered that the previous dude used a new piece of hose to connect the pump to the outlet pipe in the tank - except that it was heater hose:-O
SD, you are so right. If the fuel filter is puffy-cheeks plugged on a return system, try to sell a fuel pump too. I've seen so many FP fail shortly after clogged filter, and it's annoying for customer. Not as critical on RETURNLESS system, i suppose due to system always dead headed.
I’m 25 and I have a 91 gmc sierra r3500 with the original 350tbi 70k miles that I’ve had for about 8months. One day the truck started going into limp mode and started doing it anytime it warmed up. It’s worse now to the point where it’s running lean almost all the time. I tested the fuel pressure and was getting 9psi. The tank was old and rusty so i decided to swap in a new tank/sending unit and it still only had 9psi of fuel pressure. Rebuilt the throttle body and fuel pressure regulator and no change in pressure or running conditions. Cylinder 8 did start to develop a slight tick from the valves maybe 2weeks before this, adjusted them and they’re good now. My oil pressure has always been low since I’ve had it about 15 psi. I do notice when in limp mode in park at idle the oil pressure fluctuates from 0-60psi. I’m in the middle of replacing the oil pressure sensor/fitting now since it was leaking badly just waiting on shipping but really hope to figure this out. It’s been down 4months of the 8months I’ve owned it and really miss driving it. Any advice is appreciated as I feel like I’m getting nowhere with it.
@@ScannerDanner The truck falls flat on its face going up hill or under any load, also won’t shift into the next gear unless I get off the gas. You can feel the power drop like it’s running on half the cylinders. It has obd1, code 44 comes up which says it’s lean condition. Also code 81-82 which is QDM solenoid A and B monitored voltage differs from command which im not familiar with.
So I just installed a new 3 pin oil pressure sensor and I have a steady 30psi of oil pressure, code 44 lean condition went away. Now only have codes 81-82 still showing up, truck is still running rough/loud and feels low on power. Code 59 for the trans is the only other code and not sure if it relates to 81-82 but the original trans isn’t bolted up and the harness is disconnected but never had an issue with that.
@Dirtbiker4life man you're on it, and I can help you, it's just too much typing for me right now. I'll reply again tomorrow. I believe your lean condition is still there and code 44 is coming back. I think 9 psi is low and I want to know what fuel psi does under load or at least at wide open throttle to redline in park
@@ScannerDanner appreciate the response! I think your right about the lean condition still being there, I’ll have to test the fuel pressure later when I get home from work today. I’ll keep you posted on what I find
believe it or not i use to pull the injector/injectors out on T.B.I on gm and grind the spot weld ( carefully ) on top of the regulator screw and put it back on. Then use a 90 degree tool i made that i could "shoe horn " in to the bottom side of the throttle body unit to adjust pressure with vehicle running, 9lbs was ideal running pressure i found. Of course pump pressure had to be in range.
I had a Mk1 Ford focus that had a fuel pump issue that I diagnosed. I changed the pump and Still had a no start. I could here the pump priming but no start. I ended up deopping the tank and pulling the pump again and checking all the work and to make sure I had not leaks or the pick up had a good seal. All was fine and good so reassembled it and installed the tank. It had me going for abit as I still had no fuel to the engine. Then I realised the new pump was wired backwards compared to the car. I lifted the rear seat and switched the wires leading to the fuel pump. The vehicle came to life and ran fine for a couple years. Funny that car came back as the cheap pump that the customer had me put in died 😅. I advised him to replace it with a much better OEM quality pump and then I had to switch the fuel pump wires back to original as the new pump was wired correctly 😂. The car has not had a problem since with the fuel pump. Haha that had me going for a bit though, stupid cheap crap parts. Thank for the video Paul I always enjoy them and often re-watch them. You have helped me develop new skills and test methods as well as help me be more confident with the oscilloscope and electrical diagnostics. This channel is one of the best automotive diagnostic and repair sources around.
Thanks my friend! Nice job and the find. I've had one of those too, and believe it or not we caught it with the amp probe and scope. It had very high rpm and very low amperage (2 amps maybe on a 8-10 amp pump). It was a good clue 😀
Excellent work, terrific some up at the end of the video. There's a chance I might join your virtual class someday. But right now finishing up my second degree.
I've been hired by an old boss just to do drivability work but he doesn't maybe understand why I check things the way you do so I'm going to show him this and explain why but with that said I get to use all of my tools and the knowledge continues thanks homie or should I say GRANDPA 😂
Gates has submersible hose for this application. Had pump problem on 87 Camaro found hose connecting pump to sending unit was laying in bottom disintegrated.
Hello, and thank you for all your time and information you share. So when you deadhead test the pump. If the pressure would have gone up to 20psi. Would that have ment you have a fuel pressure regulator problem?
Purchased a 91 s10 with a 4.3. Dude unloaded a parts cannon at it because it would idle up and down, and die when given any throttle. Fuel was dripping out of the injectors trying to run so I questioned injectors but didnt want to just fire injectors at it. Guy had already replaced the entire throttle body but that still doesnt mean it was good. Infact I think the throttle body came from either a 5.0 or 5.7 because it ran fairly rich after replacing the pump. Found on a forum that with a fresh pump if you unhook the filter itll shoot fuel like 6 feet. I unbolted my filter, keyed it on and barely got a dribble. Put a pump in and tried the same thing and ended up with the gas version of a super soaker under the truck lol bolted everything back and it ran very well after that just rich.
awesome video. question: In your opinion, in the case of a bad check valve with a slow bleed-off, would you still recommend replacing the fuel pump, or would you just leave it in? I've got a '98 tacoma with the original fuel pump & a slow bleed off (drops from 40psi to 30psi in about an hour, and slowly goes to zero psi hours after that). Other than that, the pump seems to work fine; it's definitely the check valve though.
Can you recommend a good scan tool for the home mech?.. I have 35 yrs of exp. on high tech diagnostics for million dollar equipment.. but never got my own home diag. tool.. I have a no code condition of rough acceleration and don't want to start throwing parts at it.
Superb, Thanks for sharing SD Love it👍 Great video on testing properly a faulty fuel pump👍 Love the math part😉 Special thanks to James Danner & Caleb👍 Stay Safe Guy's❤
I agree James Danner seems like a pretty cool dude. It's good to watch a family atmosphere, especially this day and age...... You know I really think Paul and his brother could have a small radio show on NPR --------- they used to have an automotive show called clicking clack, I believe.
If you plugged the return line and dead head test it would it show a leak at the pump ? On a pressure test. Never mind I watched till the end . Just one question left . What are the symptoms with the bleed back with the check valve . ?
That might have been the original equipment pump, seeing as how the truck has less than 30,000 miles. The main reason I suspect that is because of the black strainer sock; I haven't seen a black sock on any modern pump recently (they're usually white, yellow or green). The old rubber hoses also didn't hold up well to the newer gasoline blends and tend to swell or crack.
I've had a fuel pump on a 2.0fsi vw golf 2006 which would run great for nearly 2hrs and then misfires into limp mode not allowing over 3k rpm. Turns out if I had low fuel level it would do it sooner than 2hrs, especially if I stayed in a layby after a hard drive and let it heat soak. The reason was a weak pump which when the return fuel comes back to the tank its hot and then warms the whole fuel tanks fuel, this caused the pump to become weaker to the point it would reduce flow under load. Was a very hard one to diagnose. Live data on vcds logs just caught it once so I could see the tps go to 0, even though my foot was planted, the rpm bounce at 3k in limp mode and then I could see the low side pressure had dropped from 5.5bar to less than 3bar. The new pump held 6bar dead irrespective of load and its is pwm system so it should hold a fixed value. The hpfp is also a big failure item on these cars but the live date log showed the hpfp pressure were excellent. Is there any way to fault find this any type of issue any quicker guys?
That pump looks like one that was not designed for ethanal fuel causing the rubber to "rot The use of an adjustable timing light is what I used to watch fuel injector pulse to the TBI's to check fuel delivery or a clogged/dirty injector.
you can check them at the TBI, but it's a pain and requires two custom bent lines with ends for the TBI/gauge fitting, high pressure rubber hose and you'll have to remove the nut and bracket holding lines at rear of passenger side, probably have to bend the line some. or maybe get some couplings or 90 fittings or a tee. you'll easily spend $100+ on fittings and ends lol there is a steel power steering return line end that will fit in place of the bought repair line end (change o-ring for fuel rated ones) I forget the part numbers offhand, but I think it was just gm/other standard return line ends. beats me, as I bought them 20+ years ago LOL
2:00 This would be where different misfires do different things. Fuel delivery issue causes total lean misfire. Ignition misfire would read rich on that bank due to unburned miss ignited mixture?
Will a fuel pump DC motor burn or short , if it has lower supplied voltage for a continuous period of time ( like a voltage drop because of corrosion on fuel pump connector ) ? I've been told, that a dc motor pumping at lower voltage than the voltage it's design to work for, would make the motor work harder. Just like a motor that has excellent supply and ground , BUT has to work more due to restriction(clogged filter or line)
i'm asking this, because i have vehicle that i changed the fuel pump motor 4-5 times.And everytime the motor shorted in a couple of months. Finally i installed Bosch pump motor and this time the fuel pump connector melted. Soldered new connector, put whole new pump this time , and no problems 2 years after the repair..to this day i think the problem was voltage drop at the connector.
I still own a truck just like that one , there so easy to work on , I will never buy a new truck again , I still have the propane system and gasoline system ,and every thing still works .
Dan can I ask you what would cause my fuel pressure to increase from 55 running and apon shutdown it jumps to 61 and holds for what seems like way to long? I've been having a no start issues on my 1996 5.7 suburban but "only when hot"? It starts fine in the mornings and winter. No codes at all either. Distributer modual? Pressure regulator not relieving pressure? I'm stumped so far! Thanks man!🤙
this is normal, when you shut it down, you lose intake vacuum. When there is no intake vacuum, you will have higher psi (same as wide open throttle). Also, you absolutely want pressure to hold on shut-down! There is no such thing as it being held too long. The important thing to do for your situation is to check the fuel psi DURING the no start. If you are sitting at 61 (or anything above 55) while you are cranking and it is still not starting, you are barking up the wrong tree. Check it for spark and injection pulse too during the no start.
one daud... Is fuel pump always be PRIME momentarily whenever key is at ON position?? In my i20, sometimes I heard fuel prime when key at ON, other times there is no fuel prime. Is this normal???
Best video out for the Tbi system. I’m having a huge problem. My 90 c1500 305. I replaced the injectors in the throttle body and now the truck won’t go over and sputters at 50mph. I’m getting 13 psi. Has new fuel regulator,new fuel filter, new injectors, new air filter, new o2 sensors. Can anyone help?
It won't go over 50mph? Let's check it for a restricted exhaust next. The quick and dirty way is to remove the upstream O2 sensor and drive it briefly. If power is significantly different with that extra hole to breath from, your cat is plugged.
The deadhead pressure test will show check valve failure in the tank but since the hose failure is up stream of the check valve ur pressure would just remain at 3.5 pounds pointing to a bad pump or failed hose - either way the tank comes down...
For the bleed down test, you are correct. Psi still bleeds down with the psi line pinched off, equals a leaking pump check valve BUT on this one, you would have also had to have had the return line blocked off as there is a bleed there too. What I'm saying is the bleed down tests would have been complicated on this one and it would have only revealed a pump check valve issue. No way to differentiate between that and the split psi line in the tank. Make sense?
Hello paul. Integrity testing . Using 5 k ohm resistor. Just in case . Signal shorted to ground. .i didnt understand that . Because . If signal is shorted to ground. Sensing current . It still read 0 volt all the time.so why jumping signal to 5 v reference. Using 5k ohm resistor?
Dan, good vid. Love your channel. Quick question though. You said there is a check valve in the pump. the split hose is hooked up before the check valve. so if the check valve is good it would still hold pressure in an assembly that is designed to hold pressure instead of has a bleed in the regulator? "even with the split hose" is what i am saying. no way to really test that on those systems like you said. so while its on the ground, may as well throw the new assembly in there.
Correct on the first question, but you could have still done the bleed down test, with the knowledge of the intentional bleed on the reg. When you pinch the return line off and psi still bleeds down, then you know there is something going on with the pump check valve or this internal leak. But you would still NOT know which of the two it was, and the internal leak is so rare in comparison to a faulty pump check valve. Then there is the aspect in that the pump check valves leak all the time, and do NOT effect RUNNING fuel pressure. So all of the bleed down testing just didn't need to be done with the low psi situation we had. It just wouldn't have told us much. Hope that makes sense.
I had a 89 Chevy I had issues with the wire to the fuel pump. Up on the firewall. There is a fused link. The link was bad. I noticed that the first day. But was told that's not the problem. I changed every part on the fuel system. A new computer and chip. After 3 weeks and $3000.00 I told the mechanic to jump the fused link. And the truck ran fine. Put in a new link. And the truck ran with no problem. I seen a 1991 2500 Chevy do the same thing. Both was the fuse like under hood. Passenger side of fire wall.
@@ScannerDanner it's all good. It's why I got my first ob's scan and wanted to know about fuel trim. And found your TH-cam channel!!! Best teacher for automotive information!
LoL, Paul I heard you condemning Danner for eating in camera. There's nothing wrong about that. And this makes your videos to be like live. I feel like I am also there with you live. Again it doesn't change the importance of the video
![New Fuel Pump - Still No Fuel Pressure - Now What? [2012 Ford E350]](http://i.ytimg.com/vi/GJ9O8pTkK4w/mqdefault.jpg)
![New Fuel Pump - Still No Fuel Pressure - Now What? [2012 Ford E350]](/img/tr.png)
This is a 1991 GM TBI system. I know it is old and we don't see many of these systems anymore, but the fundamentals still apply to ALL fuel pump and fuel delivery designs. From the mechanical return type, to mechanical return-less (regulator in the tank), to electronic return-less (no regulator) systems. Even the low pressure, delivery side, of today's GDI systems! Fundamentals my friends, they do not change and this video will be valuable information for troubleshooting all of these systems. Sure there are some minor differences in testing, depending on the fuel delivery design, but the core of this is the same!
What is covered in this video:
1. How to identify a lean condition
2. Visual spray pattern test of a TBI injector
3. Using the oxygen sensor to ID a fuel delivery problem
4. Measuring fuel psi on a return type system
5. How to check fuel pump max psi (dead-head test)
6. Fuel pump power and ground testing
7. Fuel pump current and RPM measurements
8. How to ID a good ground on your meter
9. Fuel pump motor disassembly to show brushes and commutators
10. Discussion of testing for bleed down issues
How do you reset the TPMS on a 2017 GMC Sierra? The letting air out trick didn’t work on mine.
Scanner danner, can I email you please? I've run into a no comm problem on a 11 ram 1500 5.7
Thanks Paul you stay safe talk to you later
I’ve been waiting on this video for 2 years. I’ve had troubles ever since my filter was clogged. Many thanks for the video. You provided details that others glossed over or didn’t show. 1995 K1500 TBI here. Your doing some good in this world in many ways.
@@rickyboyd2919 thank you for these words tonight, felt divinely influenced because I needed to hear this
Hey scannerdanner!
Last week our van broke down and we just so happened to breakdown next to you and you ended up saving our church van from a rats nest in a part of the engine, we got down safely and had an incredible time and I wanted to say thank you once again for helping us!
This meeting was ordained by God, no doubt in my mind. I can't stop smiling every time I think about it. I got to see some of the worship on some FB posts and I would have loved to have been there with you guys for that!
This entire thing felt like I got to meet part of an extended family that I didn't even know that I had. Pray for me to be a light in the darkness as I will do the same for you.
Awesome! Good stuff!
So, it was rodent damage?!
I couldn’t believe it when I seen it! I just removed my neighbor’s fuel pump in his 1991 GMC Sierra TBI. I watched your video and did my testing the best I could with just my multi meter. I determined it was the fuel pump since I do have voltage with a load and a solid ground at the pump and no fuel pressure at all. My filter was restricted but not blocked but figured the pump went out because of the restriction (old age). I tilted the bed and removed the pump and took a look at it afterwards and I couldn’t believe that mines had a crack (tear) in the exact spot as the one in your video! The exact same truck, make and model.
I watch videos to get myself familiarized before I start and see what I might run into since my mechanic days are over for me because of my age (70). The symptoms I had are exactly like yours in the beginning of this video. Engine starts but won’t stay running and can’t increase RPM’s, falls flat on its face in a second or two. Would run if spray carb cleaner into the throttle body. As soon as I seen the tear in my pump, I remembered this video and had a good laugh that is had the exact same problem. I’m lucky here in Hawaii as our vehicles aren’t rusty underneath, all of my fasteners were easy to remove with minimal rust. Thanks for the video and tips which made my experience in fixing my fuel problem easier to resolve.
Such a coincidence) I just replaced weak old 17 years old Fuel Pump on my Nissan Titan. All troubleshooting was done according to your book! God Bless You!
heck yeah! awesome, thank you
What a thorough breakdown. This diagnostic process eliminates variables one by one and helps to ensure the correct course of action is the final decision. An hour of diag time is worth three hours of needless parts shotgunning. Well done Danner as always. Watching you and your brother cut up is a bonus.
thanks so much! And yeah, working with my brother with my son filming is a pretty cool dynamic :-)
I appreciate you going one step further and showing where the fault in the pump portion was.
Thank you!
Good find! Shout out to the owner that keeps the truck in such a nice shape! Also, Ivan had something similar on "Eurotrash" last episode where a plastic line got disconnected internally. But first he had to undo all the other stuff people had doing beforehand to even be able to diagnose it, was quite a case.
My dad owned a 90 chevy van that had that same TBI setup. It was the first fuel injection setup I ever worked on. It is real easy to work on and fixed compared to todays F.I. setups.
easy, except for it being a van and requiring half the interior removed to get at it. lol
Okay now that I watched this and slacked off enough this morning it's back to your lectures on the Verus scan tool. The one I bought came with the board and I can follow your class along. Lecture 12 here I come.
Nice! Thanks Cullen
That "hose" isn't really a hose. It's thicker and called a pulsator. It's supposed to smooth out any pulses in the fuel delivery. A new one is supposed to come in the box with the new fuel pump. Can't ignore changing that part. Great video with lots of useful information.
No thats just a hose, pulsators are metal and look like a small old school master cylinder cap.
this model did not have a pulse dampener, some did, some did not, as @VashthStampeede said, this was just a hose. Thanks! Good info for others
@@joe1273 I know the part you are speaking of, however some were just a piece of hose about twice as thick as fuel hose only without braiding. It served the same purpose as the metal one. Nonetheless my point was a new one comes in the box for a reason, and should not be ignored when changing the fuel pump. If the pump had been recently changed, as Paul suspected, the changer screwed up by leaving the old one in. I've been ASE certified since it started in 1975 and know what I'm talking about.
I have ran into this problem before. The deadhead test showing zero pressure increase was your clue that the coupler hose at the pump was leaking. Even a weak pump would have shown some increase in pressure if that coupler hose was good. Thank you for another awesome video.
The deadhead test did not reveal anything to us beyond a weak pump. If a pump cannot reach fuel psi regulated psi (13 in this case), it is essentially running under a deadhead condition already. The regulator remained completely closed, no different than my pliers did. Make sense?
@@ScannerDanner OK So in this system had you only replaced the hose the pressure may have increased but until it surpassed the regulated pressure there would be no pressure increase with a deadhead test. And of course if it did get up to specified pressure there would be no issue. Got it and thanks again for everything you and your son do for this industry.
yes sir, exactly! Thanks so much too
31:43 - I think he forgot that was a piece of hose and trying to operate the carb. By far my most fav channel.
I’m in Texas. My Family has 3 TBI Trucks. & I get a Lot of OBS customers. I just put the adapter in place of the Filter. Plus I have a working Red Brick. They also blow out the fuel hose between the pump & strainer that can throw you for a loop. My truck is a 88 C3500 tbi 454
You guys really earn your money. Explanations very thorough so even a newbie can almost keep up.
Would love to drive to you but I can't even drive in my drive let alone to the US.
My car (2006 Opel Tigra Twintop) starts fine but cuts out after 10 secs. Fuel tank 1/4 full -- so at least the sender in the new pump I fitted is working.
Under advice of those who know more than me, I changed the fuel filter, the fuel pump (nightmare); no difference. As for the regulator, mine is within the fuel pump assembly, fitted to and part of the whole fuel pump assembly and not sold as a separate item. I have a Schrader valve on the fuel rail to take a pressure tester but 99% of kits don't have the appropriate fitting... go figure. One is arriving Monday that is supposed to have such a fitting. If I hear the click from the rear when turning key to position 2 (1 being just pushing it in) that means electrics are fine, right? ... Or having seen your vid I'd better see if I can check the wiring plug going into the pump.
Have a cheap Obd2 tool but that's not showing any codes; would buy even up to 200 dollar one if it would find the fault but have spent much time reading up on them and they all have a considerable number of detractors -- 10% of 45,000 ratings puts me off. Any advice please anyone. I see you have a vid on that so will look at it...
Thanks again for your work. I don't want to be a mechanic, just be my mechanic.
You only need to ask this question once. 3rd time I'm seeing it on various videos this morning. It gets confusing for me to follow. Reply only to my last question. Not here
@@ScannerDanner Apologies.
Mechanics even ask me: "Why do you buy expensive scanners?" and then answer the question themselves saying because "it tells you everything". I wonder how are they mechanics when they don't understand a tool that is so important in this industry. A lot of mechanics only think that a mechanical tool to replace parts is all they need.
Just started whith fuel system ..SD Book....thank you Sir !
Nice! Thanks so much! Don't let the age of the example here in this video make you tune out (some do). Fundamentals my friend, right? It still applies
Hands on is everything no matter what year it is love the vids bubba
Haha these videos with ur brother in the back ground either eaten or singing is hilarious always good to see videos like this and especially on older vehicles .
But i had a 88 S10 2.5 5speed an it did this issue an worse on turns an so i had a idea to fill the tank up or put more gas in it an sure enough that's exactly what was wrong the hose inside the tank for the fuel pump had a hole in it and when I had a full tank it would run good . An then I started to hear the fuel pump spraying inside the tank from that hose being bad so I knew for sure that's what had happend .
10 Psi per amp seem to hold true here…. 10 psi gain and 1 amp gain. Awesome work again Paul, thanks for sharing.👍🏾😎
Thanks Danner.These older systems are still relevant today
Yes they absolutely are
My 89 c2500 fuel pump did the same thing. It had a split in the rubber hose. It had a full tank of gas so I did not want to drop the tank. I removed bolts that hold the bed on except the last two on the back and left them real loose. I tilted the bed up and changed the pump.
Hi Paul I am a retired mechanic in Dover England,in 1990 i had a fuel problem that only happened when I road test the car up a steep hill,it turned out to be a split pipe like the one in your video.it was on a Vauxhall cavalier the only time in 50 years of working on cars.look up jubilee way Dover England to see the White Cliffs of Dover bridge that helped find the fault cheers
Thank you for another perfect video!!!
It is very fun to watch you and your brother together. I'm disapointed you don't have more likes but I hope you enjoy making video with your brother. Caleb shoud be showing more in the video too. Watching your videos is a job for me but it's also fun. Everyone watching yours and suchlike videos must be in love with this job.
Thank you my friend
20 years ago, one of those TBI systems kicked my butt. Rubber hose inside tank was split like that one.
Special rubber hose is required for submersed fuel line. If you don't use that, it degrades and blow a hole in it.
been there done that, replaced many of them that dry-rotted and split. a tell tale sign is listening to the fuel filler with cap off and tank less than 1/4 filled, it sounds like a waterfall inside when running or key turning to prime the system or powered with test connector.
make sure it's submersible rated fuel hose/section and it's always a great idea to replace the pump and strainer screen while at it! I got bit by that a few times.
Now we have learned why not to be a parts changer. Paul learned the hard way just like most live decisions as we all have,hopefully that is lol. Ending was awesome! I just did a fuel pump well just the hose..owner said he just replaced it with a oem. All symptoms just like this one lead to fuel pump, turned out he replaced the pump but didn't use the proper line ( external rubber fuel line) not knowing about fuel line for internal use. Always great content danners. Be well guys!
love your videos...been reading your book...but I had the same problem with my mom 98 chevy tahoe 5.7 vortec...i usually change it out myself but my mom needed it change out since it was boggy so she took it to shop...ran good for a week or so then same thing...bought new pump and drop tank...same thing cut in hose and clamps fell off...those cheap plastic ones...install some spring clamps replaced hose...didnt even replace pump and returned after a month...been running perfect for 3 years...now im working on my 95 tbi this what brought me here...trying to figure out my problem
I can help for sure! Let me know if you have questions. Just reply here whenever. I get all notifications
Love these trucks! I just bought a 93 K2500 and learning about TBI through doing! Thought at first it was carbureted and I was like "Uhhh are those injectors in the throttle body?!"
Great video helped me with my 94 suburban with TBI. Turned out I had bad ground wire, replace and truck runs Great 👍
sweet! props to you for watching through this entire video for that particular ground test
Don't knock the bacon maple bar till you try it. I had the same hesitation, now it's one of my favorite's.
Always a great video Paul. Thanks for your time.
Now wouldn’t checking pump rpm show how the hose is split and causing the “overrunning” speed of the pump, like being out of gas? The ones I’ve had the current is low, rpm is high is usually a good clue of out of gas or split hose in tank.
it wasn't much lower, not enough for me to even think along these lines my friend. 3 amps before, 4 amps after the fix, and only about 600 rpm difference too
Hey Paul it's Bruce again thanks for showing me that 91 I have a 1992 Chevrolet c1500 with a TBI on it my friend had that same problem but he didn't let me get to the fuel system before he started changing a whole bunch of stuff and by that point it was screwed so thanks for showing me that as soon as I get some money I go back to work I'm going to be getting on your your scanner dinner premium web page website with TH-cam and I'll be ordering your your books I want to take your class so I'll see you in a few weeks
thank you Bruce! Look forward to hearing from you in the comments on the premium channel
Nice find. I had a 1997 miata recently that had a brand new pump fitted less than a year before it came to me on a hook with no fuel pressure. I'm scratching my head at my fuel pressure gauge and had to go straight to the pump outlet at the tank. No pressure. Pull the pump. Split hose. BUT. I discovered that the previous dude used a new piece of hose to connect the pump to the outlet pipe in the tank - except that it was heater hose:-O
sounds like Job Security :))
SD, you are so right. If the fuel filter is puffy-cheeks plugged on a return system, try to sell a fuel pump too. I've seen so many FP fail shortly after clogged filter, and it's annoying for customer. Not as critical on RETURNLESS system, i suppose due to system always dead headed.
Love it, old school testing, Fundamentals.
This brings back memories, just goes to show how old i am LOL.Great video guys as always.
I’ve seen deteriorated hoses inside many pumps used on marine outboard engines caused by ethanol.
I’m 25 and I have a 91 gmc sierra r3500 with the original 350tbi 70k miles that I’ve had for about 8months. One day the truck started going into limp mode and started doing it anytime it warmed up. It’s worse now to the point where it’s running lean almost all the time. I tested the fuel pressure and was getting 9psi. The tank was old and rusty so i decided to swap in a new tank/sending unit and it still only had 9psi of fuel pressure. Rebuilt the throttle body and fuel pressure regulator and no change in pressure or running conditions. Cylinder 8 did start to develop a slight tick from the valves maybe 2weeks before this, adjusted them and they’re good now. My oil pressure has always been low since I’ve had it about 15 psi. I do notice when in limp mode in park at idle the oil pressure fluctuates from 0-60psi. I’m in the middle of replacing the oil pressure sensor/fitting now since it was leaking badly just waiting on shipping but really hope to figure this out. It’s been down 4months of the 8months I’ve owned it and really miss driving it. Any advice is appreciated as I feel like I’m getting nowhere with it.
There really is no limp mode on these. And how do you know it's running lean?
@@ScannerDanner The truck falls flat on its face going up hill or under any load, also won’t shift into the next gear unless I get off the gas. You can feel the power drop like it’s running on half the cylinders. It has obd1, code 44 comes up which says it’s lean condition. Also code 81-82 which is QDM solenoid A and B monitored voltage differs from command which im not familiar with.
So I just installed a new 3 pin oil pressure sensor and I have a steady 30psi of oil pressure, code 44 lean condition went away. Now only have codes 81-82 still showing up, truck is still running rough/loud and feels low on power. Code 59 for the trans is the only other code and not sure if it relates to 81-82 but the original trans isn’t bolted up and the harness is disconnected but never had an issue with that.
@Dirtbiker4life man you're on it, and I can help you, it's just too much typing for me right now.
I'll reply again tomorrow. I believe your lean condition is still there and code 44 is coming back. I think 9 psi is low and I want to know what fuel psi does under load or at least at wide open throttle to redline in park
@@ScannerDanner appreciate the response! I think your right about the lean condition still being there, I’ll have to test the fuel pressure later when I get home from work today. I’ll keep you posted on what I find
believe it or not i use to pull the injector/injectors out on T.B.I on gm and grind the spot weld ( carefully ) on top of the regulator screw and put it back on. Then use a 90 degree tool i made
that i could "shoe horn " in to the bottom side of the throttle body unit to adjust pressure with vehicle running, 9lbs was ideal running pressure i found. Of course pump pressure had to be in range.
Love all your videos, I wish I could have seen you use the old snap on brick 😜
Love the ending. Hoping for a duet...
nice to see you back on Dan tell us more about wot o2 test
:-) my name is Paul, check this video out, it will give you a good idea on how to use this test th-cam.com/video/1-2lqdDE0PQ/w-d-xo.html
I always try to watch these videos great information . Thanks for all you do .
Hello Mr. Danner thank you for sharing this video i learned lot of things from your videos.
Dead right cobba
@@grantbellinger7403 what the hell is a cobba.
Hehehehe,it’s australia n for mate,cobba
@@grantbellinger7403 OK.. WHAT EVER
I had a Mk1 Ford focus that had a fuel pump issue that I diagnosed. I changed the pump and Still had a no start. I could here the pump priming but no start. I ended up deopping the tank and pulling the pump again and checking all the work and to make sure I had not leaks or the pick up had a good seal. All was fine and good so reassembled it and installed the tank. It had me going for abit as I still had no fuel to the engine. Then I realised the new pump was wired backwards compared to the car. I lifted the rear seat and switched the wires leading to the fuel pump. The vehicle came to life and ran fine for a couple years. Funny that car came back as the cheap pump that the customer had me put in died 😅. I advised him to replace it with a much better OEM quality pump and then I had to switch the fuel pump wires back to original as the new pump was wired correctly 😂. The car has not had a problem since with the fuel pump.
Haha that had me going for a bit though, stupid cheap crap parts.
Thank for the video Paul I always enjoy them and often re-watch them. You have helped me develop new skills and test methods as well as help me be more confident with the oscilloscope and electrical diagnostics. This channel is one of the best automotive diagnostic and repair sources around.
Thanks my friend! Nice job and the find. I've had one of those too, and believe it or not we caught it with the amp probe and scope. It had very high rpm and very low amperage (2 amps maybe on a 8-10 amp pump). It was a good clue 😀
Excellent work, terrific some up at the end of the video. There's a chance I might join your virtual class someday. But right now finishing up my second degree.
Thank you! When you're ready, you can sign up here. I offer a 14 day free trial as well.
www.scannerdanner.com/join-scannerdanner-premium.html
Thanks! I feel a little smarter now... Let's get this camaro back on the road
Yay I'm not the only one to use a Solus Legend...actually it's quite a nice scan tool, had mine for about a year now and loving it.
The thumbnail, it absolutely cracks me up and the video is great 😄
Yeah, my son (editor) has fun some of these 😆
Glad you liked it!
I've been hired by an old boss just to do drivability work but he doesn't maybe understand why I check things the way you do so I'm going to show him this and explain why but with that said I get to use all of my tools and the knowledge continues thanks homie or should I say GRANDPA 😂
You have to show him one with a bad ground th-cam.com/video/rQ7tvIxQSt0/w-d-xo.html
And why we do these "extra checks"
Gates has submersible hose for this application.
Had pump problem on 87 Camaro found hose connecting pump to sending unit was laying in bottom disintegrated.
Great information. The diagnosis process was spot on.
Thank you
Thank you very much always i learn from you now i will not be late to refill my tank of fuel to prevent pump of heat and loose brushes right?
Question...what if you have to check pressure on a TBI system that has the plastic type fuel lines at the filter. How would you tap into that?
Hello, and thank you for all your time and information you share.
So when you deadhead test the pump. If the pressure would have gone up to 20psi. Would that have ment you have a fuel pressure regulator problem?
Yes!
What i like about TBI is it's so exposed, just like a carb, only better because you can actually see the spray pattern.
Purchased a 91 s10 with a 4.3. Dude unloaded a parts cannon at it because it would idle up and down, and die when given any throttle. Fuel was dripping out of the injectors trying to run so I questioned injectors but didnt want to just fire injectors at it. Guy had already replaced the entire throttle body but that still doesnt mean it was good. Infact I think the throttle body came from either a 5.0 or 5.7 because it ran fairly rich after replacing the pump. Found on a forum that with a fresh pump if you unhook the filter itll shoot fuel like 6 feet. I unbolted my filter, keyed it on and barely got a dribble. Put a pump in and tried the same thing and ended up with the gas version of a super soaker under the truck lol bolted everything back and it ran very well after that just rich.
awesome video. question: In your opinion, in the case of a bad check valve with a slow bleed-off, would you still recommend replacing the fuel pump, or would you just leave it in? I've got a '98 tacoma with the original fuel pump & a slow bleed off (drops from 40psi to 30psi in about an hour, and slowly goes to zero psi hours after that). Other than that, the pump seems to work fine; it's definitely the check valve though.
100% not a problem. They all bleed down over time. As long as you don't have a long crank time, I wouldn't worry about it!
Can you recommend a good scan tool for the home mech?.. I have 35 yrs of exp. on high tech diagnostics for million dollar equipment.. but never got my own home diag. tool.. I have a no code condition of rough acceleration and don't want to start throwing parts at it.
Superb, Thanks for sharing SD Love it👍
Great video on testing properly a faulty fuel pump👍
Love the math part😉
Special thanks to James Danner & Caleb👍
Stay Safe Guy's❤
I agree James Danner seems like a pretty cool dude. It's good to watch a family atmosphere, especially this day and age...... You know I really think Paul and his brother could have a small radio show on NPR --------- they used to have an automotive show called clicking clack, I believe.
If you plugged the return line and dead head test it would it show a leak at the pump ? On a pressure test. Never mind I watched till the end . Just one question left . What are the symptoms with the bleed back with the check valve . ?
ONLY a long crank time
That might have been the original equipment pump, seeing as how the truck has less than 30,000 miles. The main reason I suspect that is because of the black strainer sock; I haven't seen a black sock on any modern pump recently (they're usually white, yellow or green). The old rubber hoses also didn't hold up well to the newer gasoline blends and tend to swell or crack.
You may be right! 25k on that pump, which wasn't much
ethanol gas
Great job SD. truck brings back memories code 44
yes!
good job , great content, and as always great camera work Caleb .....
Beautiful, completely thorough really enjoyed watching,very good matey
That pico amp clamp automatically zeros every time you cycle the power on them. I love my pico clamps. Saves me a lot of money on 9 volt batteries 😂
So much good info here. Invaluable
Caleb/Danner/Paul
Great video - thank you!
Paul (in MA)
I've had a fuel pump on a 2.0fsi vw golf 2006 which would run great for nearly 2hrs and then misfires into limp mode not allowing over 3k rpm. Turns out if I had low fuel level it would do it sooner than 2hrs, especially if I stayed in a layby after a hard drive and let it heat soak. The reason was a weak pump which when the return fuel comes back to the tank its hot and then warms the whole fuel tanks fuel, this caused the pump to become weaker to the point it would reduce flow under load. Was a very hard one to diagnose. Live data on vcds logs just caught it once so I could see the tps go to 0, even though my foot was planted, the rpm bounce at 3k in limp mode and then I could see the low side pressure had dropped from 5.5bar to less than 3bar.
The new pump held 6bar dead irrespective of load and its is pwm system so it should hold a fixed value. The hpfp is also a big failure item on these cars but the live date log showed the hpfp pressure were excellent.
Is there any way to fault find this any type of issue any quicker guys?
That pump looks like one that was not designed for ethanal fuel causing the rubber to "rot
The use of an adjustable timing light is what I used to watch fuel injector pulse to the TBI's to check fuel delivery or a clogged/dirty injector.
you can check them at the TBI, but it's a pain and requires two custom bent lines with ends for the TBI/gauge fitting, high pressure rubber hose and you'll have to remove the nut and bracket holding lines at rear of passenger side, probably have to bend the line some. or maybe get some couplings or 90 fittings or a tee.
you'll easily spend $100+ on fittings and ends lol
there is a steel power steering return line end that will fit in place of the bought repair line end (change o-ring for fuel rated ones) I forget the part numbers offhand, but I think it was just gm/other standard return line ends. beats me, as I bought them 20+ years ago LOL
whoops, the nut and fuel line bracket is on drivers side of trucks and passenger side on vans.
At 19:55 you said not to stack the grounds, why is that? Does it effect the measurement?
It does not. The dangers would be if you dropped it with all of those stacked grounds. Make sense?
Thanks for the video! Nice to learn something new.
Love they Video's at Danner's Shop. Best Wishes Mrs. Danner!
Hay bro. Great video. Can you tell me. Would a blocked injector cause high fuel pressure.
great job teacher
i like the way you find the issues
thank you!
Thank you Captain Longwind.
🤣😉
2:00 This would be where different misfires do different things. Fuel delivery issue causes total lean misfire. Ignition misfire would read rich on that bank due to unburned miss ignited mixture?
believe it or not, the ignition misfire will still be lean
th-cam.com/video/G_89r12vZFw/w-d-xo.html
Will a fuel pump DC motor burn or short , if it has lower supplied voltage for a continuous period of time ( like a voltage drop because of corrosion on fuel pump connector ) ? I've been told, that a dc motor pumping at lower voltage than the voltage it's design to work for, would make the motor work harder. Just like a motor that has excellent supply and ground , BUT has to work more due to restriction(clogged filter or line)
i'm asking this, because i have vehicle that i changed the fuel pump motor 4-5 times.And everytime the motor shorted in a couple of months. Finally i installed Bosch pump motor and this time the fuel pump connector melted. Soldered new connector, put whole new pump this time , and no problems 2 years after the repair..to this day i think the problem was voltage drop at the connector.
I still own a truck just like that one , there so easy to work on , I will never buy a new truck again , I still have the propane system and gasoline system ,and every thing still works .
Can you determine how old the pump is by a visual inspection? As I type, you opened up the pump. 🙂
Okay but DANG that is a clean 91
Dan can I ask you what would cause my fuel pressure to increase from 55 running and apon shutdown it jumps to 61 and holds for what seems like way to long? I've been having a no start issues on my 1996 5.7 suburban but "only when hot"? It starts fine in the mornings and winter. No codes at all either. Distributer modual? Pressure regulator not relieving pressure? I'm stumped so far! Thanks man!🤙
this is normal, when you shut it down, you lose intake vacuum. When there is no intake vacuum, you will have higher psi (same as wide open throttle). Also, you absolutely want pressure to hold on shut-down! There is no such thing as it being held too long. The important thing to do for your situation is to check the fuel psi DURING the no start. If you are sitting at 61 (or anything above 55) while you are cranking and it is still not starting, you are barking up the wrong tree. Check it for spark and injection pulse too during the no start.
@@ScannerDanner Exsactly what I've been thinking recently! Your awesome thanks for the reply and advice!👍👍
Cam shaft position sensor i believe!🤙
New math formula… Count the bacon bits in Danner’s beard, divide by 3, gives you how many donuts he ate! Thanks guys.
🤣🤣
When measuring the RPM , is it always 8 humps ?! Or it depends on the fuel pump design ?!!
Most are 8, some are more
You guys are really cool and right to the point
one daud... Is fuel pump always be PRIME momentarily whenever key is at ON position?? In my i20, sometimes I heard fuel prime when key at ON, other times there is no fuel prime. Is this normal???
Some systems will not have a prime. Toyota was good for that. Other systems need the key to remain off for at least 5 seconds to get a second prime
@@ScannerDanner its hyundai i20 India in my case.
Would that truck happen to be for sale? i may be interested if the miles are as low as Stated in the beginning? Thanks!
No sir 😔
Bacon and phlegm donuts, lol.
I gotta say thank goodness for spellcheck on that sentence.
🤣🤣
On my 88 the fuel line to the tbi is braided so I'm able to tee in right behind the tbi.
Best video out for the Tbi system. I’m having a huge problem. My 90 c1500 305. I replaced the injectors in the throttle body and now the truck won’t go over and sputters at 50mph. I’m getting 13 psi. Has new fuel regulator,new fuel filter, new injectors, new air filter, new o2 sensors. Can anyone help?
It won't go over 50mph? Let's check it for a restricted exhaust next. The quick and dirty way is to remove the upstream O2 sensor and drive it briefly. If power is significantly different with that extra hole to breath from, your cat is plugged.
The deadhead pressure test will show check valve failure in the tank but since the hose failure is up stream of the check valve ur pressure would just remain at 3.5 pounds pointing to a bad pump or failed hose - either way the tank comes down...
For the bleed down test, you are correct. Psi still bleeds down with the psi line pinched off, equals a leaking pump check valve BUT on this one, you would have also had to have had the return line blocked off as there is a bleed there too. What I'm saying is the bleed down tests would have been complicated on this one and it would have only revealed a pump check valve issue. No way to differentiate between that and the split psi line in the tank. Make sense?
God bless you guys!! I love these test methods! Keep the videos coming!
Good job
Hello paul. Integrity testing . Using 5 k ohm resistor. Just in case . Signal shorted to ground. .i didnt understand that . Because . If signal is shorted to ground. Sensing current . It still read 0 volt all the time.so why jumping signal to 5 v reference. Using 5k ohm resistor?
Sorry paul . I ve found that hhhh. I have seen the ford 4 wire maf sensor tests. Is to protect the 5 v reference. . Now i do understand . Sorry again
Nice! No problem at all my friend. Thank you
Dan, good vid. Love your channel. Quick question though. You said there is a check valve in the pump. the split hose is hooked up before the check valve. so if the check valve is good it would still hold pressure in an assembly that is designed to hold pressure instead of has a bleed in the regulator? "even with the split hose" is what i am saying. no way to really test that on those systems like you said. so while its on the ground, may as well throw the new assembly in there.
Correct on the first question, but you could have still done the bleed down test, with the knowledge of the intentional bleed on the reg. When you pinch the return line off and psi still bleeds down, then you know there is something going on with the pump check valve or this internal leak. But you would still NOT know which of the two it was, and the internal leak is so rare in comparison to a faulty pump check valve. Then there is the aspect in that the pump check valves leak all the time, and do NOT effect RUNNING fuel pressure. So all of the bleed down testing just didn't need to be done with the low psi situation we had. It just wouldn't have told us much. Hope that makes sense.
@@ScannerDanner thank u for getting back with me. Believe you even mention that in your video sorry I overlooked it have a good one
I wish you and your brother lived next door to me. OMG I'd be in so much trouble with my wife! I love you guys.
🤣
Thank you Paul and Caleb great video !!
I had a 89 Chevy I had issues with the wire to the fuel pump. Up on the firewall. There is a fused link. The link was bad. I noticed that the first day. But was told that's not the problem. I changed every part on the fuel system. A new computer and chip. After 3 weeks and $3000.00 I told the mechanic to jump the fused link. And the truck ran fine. Put in a new link. And the truck ran with no problem. I seen a 1991 2500 Chevy do the same thing. Both was the fuse like under hood. Passenger side of fire wall.
$3000!! Damn, that is a big shotgun they were using
@@ScannerDanner it's all good. It's why I got my first ob's scan and wanted to know about fuel trim. And found your TH-cam channel!!! Best teacher for automotive information!
@@stevenpellegrino997 thanks so much!
Thanks for sharing Paul... Cheers.
LoL, Paul I heard you condemning Danner for eating in camera. There's nothing wrong about that. And this makes your videos to be like live. I feel like I am also there with you live.
Again it doesn't change the importance of the video
🤣 I just didn't want you guys to have to deal with eating noises lol, as I hate to even hear myself eat.
Thanks my friend