strange problem, need help

[NintendoKD]

Does your truck have an egr?If it does pull the vacume line off of it and plug the line with your finger, not sure if you tried that yet. Also if you do you could have a large vac leak where it enters the plenum.

I did this, egr works, and does not get stuck. I sprayed carb cleaner all around this area, no change in idle. There is a change in the idle when I apply a vacuum to the EGR actuator, and plug the vacuum line.

 

[NintendoKD]

injector

I have the Same year truck same engine had the same problems you have a bad mass air flow sensor,no cleaning it won't fix it.Replace it then it will probably pop a code for lean bank one trim replace the fuel injector and you will be good to go.

Why would you have to replace the injector? All of the ones I got from the scrap yard have good spray patterns, and all have good resistance across the pins. Maybe the MAF is the problem, despite having the backprobe test done and it turned out good. The diagnostic test with the solus, and codis turned out good as well. I performed an maf only test on the maf and it turned up good. I understand the principle of operation, however, the thing could be bad or the PCM could be misinterpreting the information received. Or maybe I am reading too far into it because I have been looking at this problem so long.

 

[mikeg216]

Why would you have to replace the injector? All of the ones I got from the scrap yard have good spray patterns, and all have good resistance across the pins. Maybe the MAF is the problem, despite having the backprobe test done and it turned out good. The diagnostic test with the solus, and codis turned out good as well. I performed an maf only test on the maf and it turned up good. I understand the principle of operation, however, the thing could be bad or the PCM could be misinterpreting the information received. Or maybe I am reading too far into it because I have been looking at this problem so long.

i know the feeling just back up and take look at it from a more simple point of view,just try the maf i tested mine a bunch of times cleaned it and all that good stuff showed no issues then i replaced it on a whim and bam! its running lots better now it set off a new code which is 0171 bank 1 lean and as far as i know thats a fuel injector related issue

 

[NintendoKD]

I am going to try that, I have to wait till my buddy can give me a ride.

 

[NintendoKD]

picture time

Got some pictures for ya, finally got everything worked out.
adding a new ground

my new injector connectors, don't hate

new "well new to me anyhow" injectors

painted my front grille, now doesn't look like a leper

interior was filthy when I got it, soon was remedied

ghetto fabulous fuel line repair work

my hood stand before I replaced the pistons

I have more, just see my album:
here

 

[AuroraZero]

Is it actually running right now?

 

[NintendoKD]

maf

So I installed the new maf from autozone, which is a re-manufactured unit, and the initial outcome was a little scary. I thought, holy crap, this thing runs worse now, waaaay worse. I revved it, and it evened out, MAP relearn process, and still runs the same, if not, worse, by a very small amount. I hooked up the inductive timing light, and it still misfires, the same way on all cyl. I scanned or codes, and no codes. ??????????

 

[mikeg216]

So I installed the new maf from autozone, which is a re-manufactured unit, and the initial outcome was a little scary. I thought, holy crap, this thing runs worse now, waaaay worse. I revved it, and it evened out, MAP relearn process, and still runs the same, if not, worse, by a very small amount. I hooked up the inductive timing light, and it still misfires, the same way on all cyl. I scanned or codes, and no codes. ??????????

Disconnect the battery hook it back up drive around for about 20 mins if you have any codes they should pop up its not an instantaneous process

 

[NintendoKD]

Gonna try that, have to go to the commissary to buy a plunger and some liquid plumber.

 

[mikeg216]

Gonna try that, have to go to the commissary to buy a plunger and some liquid plumber.

oh and just an fyi the p0135 code could mean you have your o2 wires crossed or ya have a bad connection

 

[NintendoKD]

intermittent, hasn't come back up yet, after a good cleaning with maf cleaner *knock on wood* the connectors were crossed before, this happened after I corrected them.

 

[NintendoKD]

still no codes, no improvement though, runs worse than before, with "old" MAF

 

[96exp5.0]

I feel your pain just bought a 96 ex 5.0 runs perfect for about 3 second when you start it then it starts missing backfires and barely drives has no power, turn of key and runs superb for three seconds does this all day. things i tryed replaced cats replaced 02 sensors wires plugs coils check fuel pressure tryed differnt maf vac selnoid replaced thing on egr valve replaced crank angle sensor and cam position sensor. when it starts to run rogh you run the rpms up but you have to do it very carefully if you do it fast forget it it breaks up if you try to do it in drive nothing changes. Why does it start up and rev great until you hit the like 3 second mark? PCM?

 

[NintendoKD]

I am going to post a diagnostic as I do it tomorrow. I drove 107 miles from the gas station to Amboy, and back. I used a total of 5.7 gallons of gas. that is ~ 18.77 mpg, this is with it running rich, and I haven't a good alignment, and without proper tire inflation. I am almost certain that the PCM is bad. The trip was mostly open road, with a few stops in between, a mean travel speed of 55.2 MPH. The rpm's stayed mostly under 2000, personally this is pretty good and I think that this is better than most people get out of their 4.0 SOHC 2wd sploders. I plan to make that much better. The 4gas told me my HC ppm count was a mean average of 45ppm so I can pass smog fine. I have a very special modification that brings down my HC count, and aids in fuel economy, to be revealed at a later date. I also did not drive like a granny, drove the speed limit and accelerated as a warm blooded 27 year old would. wish me luck tomorrow at the smoggers. I also stopped by the Autozone on my way back, and I picked up a new AIT sensor, made little or no difference.

 

[NintendoKD]

I feel your pain just bought a 96 ex 5.0 runs perfect for about 3 second when you start it then it starts missing backfires and barely drives has no power, turn of key and runs superb for three seconds does this all day. things i tryed replaced cats replaced 02 sensors wires plugs coils check fuel pressure tryed differnt maf vac selnoid replaced thing on egr valve replaced crank angle sensor and cam position sensor. when it starts to run rogh you run the rpms up but you have to do it very carefully if you do it fast forget it it breaks up if you try to do it in drive nothing changes. Why does it start up and rev great until you hit the like 3 second mark? PCM?

I have a no crap test for that, I will detail it for you tomorrow, I take it that you have no codes?

 

[96exp5.0]

I have a no crap test for that, I will detail it for you tomorrow, I take it that you have no codes?

Nope no codes except 4 transmisson codes I have to figure out because I put a 98 trans. in it and I repinned the plug but some reason it didn't work. Ill tackle that next.

 

[mikeg216]

I am going to post a diagnostic as I do it tomorrow. I drove 107 miles from the gas station to Amboy, and back. I used a total of 5.7 gallons of gas. that is ~ 18.77 mpg, this is with it running rich, and I haven't a good alignment, and without proper tire inflation. I am almost certain that the PCM is bad. The trip was mostly open road, with a few stops in between, a mean travel speed of 55.2 MPH. The rpm's stayed mostly under 2000, personally this is pretty good and I think that this is better than most people get out of their 4.0 SOHC 2wd sploders. I plan to make that much better. The 4gas told me my HC ppm count was a mean average of 45ppm so I can pass smog fine. I have a very special modification that brings down my HC count, and aids in fuel economy, to be revealed at a later date. I also did not drive like a granny, drove the speed limit and accelerated as a warm blooded 27 year old would. wish me luck tomorrow at the smoggers. I also stopped by the Autozone on my way back, and I picked up a new AIT sensor, made little or no difference.

If you are getting 18mpg then you are good to go

 

[96exp5.0]

No crap test? Never heard of it. Thank you I really appreciate any help you can spare.

 

[96exp5.0]

Nintendokd can you take a closeup picture of your coil it looks like it has a grey powderish residue all around it i cant tell for sure from the pic you have posted.

 

[joe doe]

man nintendo kd my ex runs good and i dont get more than 15mpg...lol.....but i dont baby it ,most my driving is mixed small town and highway but i average 15mpg .but i dont drive 55 to often either .

you have been thru alot with this suv .i commend your commitment ,i may have given up by now .
good luck man ,and as always thanks for your service .my brother from another mother was a marine and was in desert storm .