I am so done with this sh*t, I think time for new PCM

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unity

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Hi all,

Not posting much lately, too dang busy. Anyway I need some help. I tune my car, its fine then something like what happened today happens. The car has a hard time starting, burns gas bad and today the timing is totally retarded. I can hit 3.5K RPM and a geo Metro could still pass me. Its bad under load. Under partial load not so bad.

I could get a log, but it never reads right. (I have SCT Pro Racer, ect.)

Anyway. At this point I think the PCM is bad. Its a 96 so no EDIS. Or the VRCM. Whichever controls spark output.

I think I will start with the computer. I think the code is EPB2 or something like that. A code match would be great! Then I will move onto the harder relay module.

On another note - my blower fan went out today. Probably the connection AGAIN. That happened later in the day though, not at the same time.

So anyone have a computer for a 96?
 
I just pulled codes.

P0174: SYS TO LEAN
P1131: Lack of H0252 SWT LEAN
P1151: Lack of H02S21 SWT LEAN

Did an O2 sensor blow?
 
Odd codes...

Hmmm... there is a 96 in a Local junkyard I'm going by tomorrow... I can try and grab it for you.
 
Stupid ? but have you disconnected the negative of the battery and tried to reset it? I may have that coded ecm in my basement at Home. If I find it Ill send you a PM.
 
I would undo the main engine harness connector, clean it and expand the connectors out tp tighten them up.
 
Little history here. Fuel filter is about a month old and so are the O2 sensors. Tommy did notice in one of my logs that even new one side was off. I forget the issue, he may recall. Also the MAF is new OEM. No visible vacuum leaks and the idle stumbles around 700. I have a backup IAC I am going to toss one for :q:q:q:qs. Take 10 seconds.

So there is the chance my new Bosch O2 sensors are crap - what surprise.

But I want to be sure.
 
96, hard to find, even more difficult to get good parts since they get scavenged if discovered...I found a junkyard 96 a couple of months ago, and got the imrc's vcrm and ecu-all parts are functional and like gold.:D I'll help out if I can-
 
Battery disconnect did nothing. I will check out the umbilical. It was NOT fun driving to work today. Stalled a few times when stopping. I may pick up new O2s on the way home - assuming it makes it.
 
Which side is bank 2? I have two new Bosch to install. No one firkin carries anything else.... But I will return both used ones so FAKEM.
 
Ok. So I replaced both O2 sensors and feel all warm and fuzzy knowing they are new. But it did not fix it.

So I did the spark plugs. Probably not the problem but by looking at them something may hint at something. Other than looking like they were being run lean for a short while (orange color), they were clean and all matched. Needed new ones anyway.

New was IAC. No fix but now I know my backup is good. Did the TPS, again I know I have a good spare.

So that left me with MAF and vac leak. I once again looked for a leak (starting fluid) and found nothing. Then it occurred to me to run the car without the MAF connected. No change - odd, there should have been. So the car is basically operating like it has no MAF and that makes perfect sense.

So it may be the MAF. Its new and looks great physically. I have other MAFs I can swap on but I am wondering if it has a fusible link or anything? The MAF is the last thing I can think of unless the fuel I have is bad.

Thoughts?
 
Wow. Dead here tonight :) lol

Ok, so I unplugged the MAF while running, there was a change....

Next in line was fuel pressure test. I went to bleed the line first - nothing? Odd. So I started the car. Fuel sure came out of the valve when pressed. Killed the engine and checked right away - nothing.

So I have gone from a possible abundance of air to a lack of fuel. Lines look good. Filter is new. Fuel must be ok, its a pressure issue. FPR could be the issue. Pump is about a year old I think, maybe two years. Walbro 255 with the wrong dang filter (thanks Bill @ SCP).
 
More to add. Had a used/backup FRP dropped off. No change. Pinched return line - no fuel pressure build-up, no change. Afraid to pinch it off further.

Maybe a fuel injector stuck wide open? But then I should have seen something on a plug.
 
Have you checked fuel pressure at the schrader valve?

Sounds like a weird problem.
I have never seen a injector stuck to the point were it sprays all the time, and yes you would see that on a plug.
It would be wet I would think.
 
Pressure is coming in at about 15 and drops off fast with RPM climb. I am really leaning towards a bad pump. The Walbro 255 has an internal check valve and pressure release valve.

Now if the pressure would stay at the rail when cycling the pump without starting the car I would still lean towards the FPR. The one I installed to test was used so who knows, it could be bad. They are cheap and easy to replace so I may just get one anyway to rule it out 100%. But even with a bad FPR there should be some residual pressure. Now if the check valve goes in the pump, then there is a 100% drop off. But the pump is a little bit of a pain and I cant do it until next weekend so FPR in the mean time.
 
I disconnected the FPR and it seems the fuel pressure climbed. Its fairly drivable that way, I just can not hammer the peddle.
 
put your base fuel table back to stock...in the mean time.
hopefully the "pig rich" programming will help offset some of the lean condition.

with a bad/weak fuel pump the variance between "commanded and delivered" is probably "pretty high"..

If you put it back to pig rich, you might luckout and have it alot closer than a performance fuel table would be.
(jus a thought from the far side)
 
Cool. Will do in the mean time. The new pump cant get in til next weekend so anything will help. I just hope it does not get any worse.
 
Dam the old pump is only a year old....still sounds like someting weird is going on.
 
Ya, just over a year. Installed March of 08.

I am going to inspect the lines again, but at this point I am very certain its the pump.
 
Ok, just adding to my "journal". For :q:q:q:qs I bought a new FRP to erase all doubt. Anyway, before I could get it installed the car had a complete die out pretty much. Could not even tap the peddle without it threatening to die.

This is how it happened. Long start as expected. Driving down main street. Stuttering here and there as expected. Get to another red light, press gently but it dies. Get it going enough to pull into Advance. Leave it running. get out, car has plenty-o-power and I am off to what I set out to do. But as I get to another red light it dies upon acceleration and will not get any power or build any RPM. Then after getting it to at least make a u-turn I sit for a while and suddenly pressure it back enough to make it back to my shop then home.

HAS to be a fuel pump issue. Ordering one again from Bill tomorrow. I just wonder if it will make it til Saturday and for that matter the 40 minute drive to the shop its going to for me to work on it.

Frack.
 
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