Need some help please!
11-27-2017, 04:38 AM
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Need some help please!
ok this truck could end up being the death of me, lol. It’s a 89 with the 3.0 V6 4WD. I did a complete top end rebuild this past August and after getting it all back together it ran great for a while, well after sitting up for about a month cause I had to change the seal in the rear end it’s like it had no power. It would do ok till I got about 50mph I could have my foot to the floor and it would not hold speed. Timing was good and everything and I changed the fuel filter cause I don’t know the last time it was changed, well after changing it all the sudden it got better and I could drive it again. So I thought I had it figured out, fast forward to now the truck sat up for about 2-3 weeks cause I had to change my rotors and calibers. After that I finally thought I could drive this truck to work finally. Well now it’s dokng the same thing, no power once you get to about 50-55 mph. Also when it’s idling sometimes it almost sounds like it’s maybe backfiring a little bit or something I’m not sure. Other times it idles perfect. Do y’all have any idea what I should try next? I did seafoam the tank a while back so could it have maybe knocked a bunch of trash in my tank loose and plugged up my fuel filter again? Also no check engine light is on. I appreciate any help or advice, I have dumped a lot of money in this truck and just want to be able to drive it.
11-27-2017, 04:58 AM
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The stuttering idle and low power at higher speeds are pretty common signs of a dying fuel pump. My gut says start there. Also, as obvious as it sounds, make sure your intake and vacuum lines are clean, tight and correct. My old 3.0 had low power for a long time too, figured out the ECU was compensating for a vacuum leak, and was killing power as a result.
Last edited by Toyota345; 11-27-2017 at 05:03 AM.
11-27-2017, 11:27 AM
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The stuttering idle and low power at higher speeds are pretty common signs of a dying fuel pump. My gut says start there. Also, as obvious as it sounds, make sure your intake and vacuum lines are clean, tight and correct. My old 3.0 had low power for a long time too, figured out the ECU was compensating for a vacuum leak, and was killing power as a result.
11-27-2017, 01:31 PM
#4
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It is entirely possible that your fuel filter is plugged up again, pull it out and shake out anything that might be on the inlet side, blow through it backward and catch whatever comes out either in a white rag or a mason jar (better because you can see water in the gas), see if you have chunks in there. If you do, you'll want to pull the tank and clean it out. You may as well put a new pump in it while it's out if you have the cash.
11-27-2017, 03:17 PM
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Ill check that out as soon as I can find a pressure tool. Do you think its possible that some junk could have got in and plugged the new filter? I did put a bottle of seafoam in there a while back and I use it alot on my lease so maybe bouncing around and stuff stirred more up.
11-27-2017, 03:47 PM
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Just able to get back online. Changed the fuel filter and it’s back running good again except for a little backfire and idle surge so the fuel filter is the biggest issue right now. I’ll be dropping the tank and cleaning it this weekend then I’ll start working on the other issues
11-27-2017, 04:16 PM
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Just able to get back online. Changed the fuel filter and it’s back running good again except for a little backfire and idle surge so the fuel filter is the biggest issue right now. I’ll be dropping the tank and cleaning it this weekend then I’ll start working on the other issues
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11-27-2017, 04:51 PM
#8
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Did you get a sample out of the fuel filter? what did it look like? Are you planning to replace the fuel pump? It may fail on you soon if it had to pass a bunch of rust scale from your tank. And don't forget to blow out the line from the tank to the filter after you clean out the tank.
11-27-2017, 07:10 PM
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Did you get a sample out of the fuel filter? what did it look like? Are you planning to replace the fuel pump? It may fail on you soon if it had to pass a bunch of rust scale from your tank. And don't forget to blow out the line from the tank to the filter after you clean out the tank.
11-28-2017, 02:10 AM
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can i recommend in future giving us all a slightly more sensible thread title. "Help me", is not very descriptive haha. maybe u are just going batty insane with this issue so i forgive you.
i looked at ur post history to find out what model "truck" you have.
u had a 94 pickup at some stage yea? and now its defi ately an 89?
anyway, u should never run seafoam through a fueltank. the crud that the strainer (attached to in tank fuel pump) stops at the atrainer, but if u disolve it, in something like seafoam, it gets through the strainer very quickly.
You will need to replace the entire fuel pump assembly most likely, as the gunk entering the fuel pump is likely to sit around on the magnetic areas and cause tightness and overheating.
Going forwards, never try fuel additives, in any vehicle. any maintenance on the fuel system should be done via the intake manifold or with the injectors removed and bench cleaned.
it would be wise to have the injectors cleaned after all these problems.
i looked at ur post history to find out what model "truck" you have.
u had a 94 pickup at some stage yea? and now its defi ately an 89?
anyway, u should never run seafoam through a fueltank. the crud that the strainer (attached to in tank fuel pump) stops at the atrainer, but if u disolve it, in something like seafoam, it gets through the strainer very quickly.
You will need to replace the entire fuel pump assembly most likely, as the gunk entering the fuel pump is likely to sit around on the magnetic areas and cause tightness and overheating.
Going forwards, never try fuel additives, in any vehicle. any maintenance on the fuel system should be done via the intake manifold or with the injectors removed and bench cleaned.
it would be wise to have the injectors cleaned after all these problems.
Last edited by Thommo Thompson; 11-28-2017 at 02:11 AM.
11-28-2017, 06:07 AM
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can i recommend in future giving us all a slightly more sensible thread title. "Help me", is not very descriptive haha. maybe u are just going batty insane with this issue so i forgive you.
i looked at ur post history to find out what model "truck" you have.
u had a 94 pickup at some stage yea? and now its defi ately an 89?
anyway, u should never run seafoam through a fueltank. the crud that the strainer (attached to in tank fuel pump) stops at the atrainer, but if u disolve it, in something like seafoam, it gets through the strainer very quickly.
You will need to replace the entire fuel pump assembly most likely, as the gunk entering the fuel pump is likely to sit around on the magnetic areas and cause tightness and overheating.
Going forwards, never try fuel additives, in any vehicle. any maintenance on the fuel system should be done via the intake manifold or with the injectors removed and bench cleaned.
it would be wise to have the injectors cleaned after all these problems.
i looked at ur post history to find out what model "truck" you have.
u had a 94 pickup at some stage yea? and now its defi ately an 89?
anyway, u should never run seafoam through a fueltank. the crud that the strainer (attached to in tank fuel pump) stops at the atrainer, but if u disolve it, in something like seafoam, it gets through the strainer very quickly.
You will need to replace the entire fuel pump assembly most likely, as the gunk entering the fuel pump is likely to sit around on the magnetic areas and cause tightness and overheating.
Going forwards, never try fuel additives, in any vehicle. any maintenance on the fuel system should be done via the intake manifold or with the injectors removed and bench cleaned.
it would be wise to have the injectors cleaned after all these problems.
11-28-2017, 02:34 PM
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surging idle? this is the first time uve mentioned that. is it surging, or stuttering.
surging is when it climbs above normal idle and falls back down to below idle and repeats. stuttering is a miss or poor combustion leading to an erratic rough idle.
surging is when it climbs above normal idle and falls back down to below idle and repeats. stuttering is a miss or poor combustion leading to an erratic rough idle.
11-28-2017, 02:51 PM
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it was surging but now it ain’t doing it no more after some fresh gas. Now I just have random misfires but it only misfires when it warms up. I don’t get it, this truck will be the death of me. Lol
11-28-2017, 03:41 PM
#14
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can i recommend in future giving us all a slightly more sensible thread title. "Help me", is not very descriptive haha. maybe u are just going batty insane with this issue so i forgive you.
i looked at ur post history to find out what model "truck" you have.
u had a 94 pickup at some stage yea? and now its defi ately an 89?
anyway, u should never run seafoam through a fueltank. the crud that the strainer (attached to in tank fuel pump) stops at the atrainer, but if u disolve it, in something like seafoam, it gets through the strainer very quickly.
You will need to replace the entire fuel pump assembly most likely, as the gunk entering the fuel pump is likely to sit around on the magnetic areas and cause tightness and overheating.
Going forwards, never try fuel additives, in any vehicle. any maintenance on the fuel system should be done via the intake manifold or with the injectors removed and bench cleaned.
it would be wise to have the injectors cleaned after all these problems.
i looked at ur post history to find out what model "truck" you have.
u had a 94 pickup at some stage yea? and now its defi ately an 89?
anyway, u should never run seafoam through a fueltank. the crud that the strainer (attached to in tank fuel pump) stops at the atrainer, but if u disolve it, in something like seafoam, it gets through the strainer very quickly.
You will need to replace the entire fuel pump assembly most likely, as the gunk entering the fuel pump is likely to sit around on the magnetic areas and cause tightness and overheating.
Going forwards, never try fuel additives, in any vehicle. any maintenance on the fuel system should be done via the intake manifold or with the injectors removed and bench cleaned.
it would be wise to have the injectors cleaned after all these problems.
11-28-2017, 10:33 PM
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the reason its happening only when hot is because when its at operating temp it starts to run leaner because thats how the engineers designed it. Once it gets hot, it starts taking readings from the O2 sensor and maps the fuel to make the O2 readings in the exhaust minimal, for a stoichetric mix (most efficient mix). before that time it runs in what is called "open loop mode" where the fuel metering is fixed at a rich preprogrammed setting. so ur problem is when the fuel metering starts using the leaner more correct mixture.
99% of the armchair experts on the internet will tell u that a hot missfire problem is a fault of the O2 sensor. this is garbage.
most often the fault is elsewhere and is caused by the change down to this lower fuel mixture which makes ignition faults and vacuum leaks more prominent or pronounced.
To summarize, due to the poor atomization of cold fuel, an engine needs to run richer than an O2 sensor can monitor when it is cold. therefor the o2 sensor is ignored until operating temperature is reached and mixtures become readable by the O2 sensor.
99% of the armchair experts on the internet will tell u that a hot missfire problem is a fault of the O2 sensor. this is garbage.
most often the fault is elsewhere and is caused by the change down to this lower fuel mixture which makes ignition faults and vacuum leaks more prominent or pronounced.
To summarize, due to the poor atomization of cold fuel, an engine needs to run richer than an O2 sensor can monitor when it is cold. therefor the o2 sensor is ignored until operating temperature is reached and mixtures become readable by the O2 sensor.
Last edited by Thommo Thompson; 11-28-2017 at 10:38 PM.
11-29-2017, 04:48 AM
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the reason its happening only when hot is because when its at operating temp it starts to run leaner because thats how the engineers designed it. Once it gets hot, it starts taking readings from the O2 sensor and maps the fuel to make the O2 readings in the exhaust minimal, for a stoichetric mix (most efficient mix). before that time it runs in what is called "open loop mode" where the fuel metering is fixed at a rich preprogrammed setting. so ur problem is when the fuel metering starts using the leaner more correct mixture.
99% of the armchair experts on the internet will tell u that a hot missfire problem is a fault of the O2 sensor. this is garbage.
most often the fault is elsewhere and is caused by the change down to this lower fuel mixture which makes ignition faults and vacuum leaks more prominent or pronounced.
To summarize, due to the poor atomization of cold fuel, an engine needs to run richer than an O2 sensor can monitor when it is cold. therefor the o2 sensor is ignored until operating temperature is reached and mixtures become readable by the O2 sensor.
99% of the armchair experts on the internet will tell u that a hot missfire problem is a fault of the O2 sensor. this is garbage.
most often the fault is elsewhere and is caused by the change down to this lower fuel mixture which makes ignition faults and vacuum leaks more prominent or pronounced.
To summarize, due to the poor atomization of cold fuel, an engine needs to run richer than an O2 sensor can monitor when it is cold. therefor the o2 sensor is ignored until operating temperature is reached and mixtures become readable by the O2 sensor.
11-29-2017, 06:38 AM
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wow that is an awesome explanation. Well until I can get time to drop the tank to clean it and change the pump I decided to do a couple of other checks. Tested Cold start injector, ohms are good and it passed the leak test the fsm tells you to do. Checked the O2 sensor and I think it was 5-6 ohms which is within spec according to the fsm. I think I checked the right sensor for ECT but need to confirm. If I was on the right one it was at 450 ohms which is out of spec.
