88 2.5L running issue :( please help (Page 2/5)
gtxbullet NOV 09, 09:40 PM

quote
Originally posted by fieroguru:

Might check the coil pack connector harness end. I was having random loss of power and sometimes a really low idle that would come and go. Eventually it stayed in the low power mode and was able to limp it home. Never set a code... but this was the culprit:



both connectors that attach to the ICM are good, though the rubber weather seals have become enlarged from absorbing Dielectric grease...very weird.

I had to wire my tachometer into the large conector as it was faulty (about 2 years ago), removing it and not having it connected to the tach doesn't change anything.

this really has had me puzzled. I've been living with it for years, and this last year it got worse to where it will actually stall out.

but I've just completely rebuilt the engine and replaced EVERYTHING.

it has to be harness related as it's the only thing I haven't restored to perfection on the drivetrain...and the original fuel injector.
Indiana_resto_guy NOV 10, 10:15 PM
It might be a fuel pressure regulator problem.
gtxbullet NOV 11, 01:32 PM

quote
Originally posted by Indiana_resto_guy:

It might be a fuel pressure regulator problem.



Fuel pressure regulator has already been replaced.
Everything ignition and fuel related has been replaced except the fuel injector.
I swapped out the fuel injector for another 1 and it didn't change anything so I put the original 1 back in.

What I'm thinking all do is put some stock style coil packs back on and replace the icm harness end ( which I already ordered from the Fiero store)
I also have a few spare O2 sensors so Ill replace that too as Its a year old.
gtxbullet NOV 13, 07:18 PM
update: engine dies when letting of the gas about 40-50% of the time now...

might just be the 20-30 degree weather we now have...

looking forward to my new ICM connector and pigtail.

if that doesn't solve the issue, I'm going to add another ground for the ICM.

then if the problem is still there I'll be deleting the EGR. If no change, then the EGR will go back on.

the last thing would be the Fuel Injector. I really hope thats not it, because it's $90.00 at autozone, and give or take $5-10 online everywhere

wish I could just find a CARB intake and get rid of the whole computer set up. lol

[This message has been edited by gtxbullet (edited 11-13-2012).]

gtxbullet NOV 22, 12:39 PM
replaced the ICM connector and there is no difference...
now literally the only thing that hasn't been replaced is the injector...
I continue to get a random code 42 every once in awhile.
which I believe is evap system... but when I plug of the Evap at vac lines from the throttle body it doesn't change anything and I still get the code every once in awhile.
86soon3.4 NOV 22, 01:43 PM
Code 42 is for ECT. Electric Spark Timing.

Go to PFF main page and look at the ECM codes.

Steve
gtxbullet NOV 22, 05:57 PM

quote
Originally posted by 86soon3.4:

Code 42 is for ECT. Electric Spark Timing.

Go to PFF main page and look at the ECM codes.

Steve



so it is!!
everything ignition related is brand new...
I'll try playing around with the wires on the harness thats will spark plug wires. I had the same issue with my V 6 swap so maybe I'm having it now too.
that would make a lot of sense!
I'll try and figure it out tomorrow as my fastback is pretty much done.
theogre NOV 22, 06:01 PM

quote
Originally posted by 86soon3.4:
Code 42 is for ECT. Electric Spark Timing.
Go to PFF main page and look at the ECM codes.


Again read my Cave, DIS Ignition + 87-88 DIS Duke ECM

Check Grounds bolted to Trans bell housing. DIS ground goes to bell housing. (This is G504)

Random DTC 42 could be need a PROM update but need to eliminate grounds etc first.

Could be a Dieing ECM. Pull console and Carefully Try warming up ECM w/ hair drier.
See my Cave, ECM Heat
gtxbullet NOV 22, 06:09 PM

quote
Originally posted by theogre:

Again read my Cave, DIS Ignition + 87-88 DIS Duke ECM

Check Grounds bolted to Trans bell housing. DIS ground goes to bell housing. (This is G504)

Random DTC 42 could be need a PROM update but need to eliminate grounds etc first.

Could be a Dieing ECM. Pull console and Carefully Try warming up ECM w/ hair drier.
See my Cave, ECM Heat



thanks for the info!!!

my ECM in Remanufactured. I have tried several ECM's and the problem doesn't go away
. I'll recheck my grounds. I added a bunch of extra grounds just for the heck of it.
I should know more later tonight after the big bird stops dancing in my gut. lol
gtxbullet NOV 27, 04:37 PM
still clueless...

so here's a list of parts that are new in the last 1-2 years. (the problem has existed for 3ish years)

replaced:
ICM Harness section (with fiero store part)
computer
wires
plugs
IAC
PCV
Rubber Vacuum Lines
Fuel Pump
Fuel Filter
ICM
Crank Sensor
Coils
O2 Sensor
added 2 more grounding straps to the engine and transmission (6 or 8 gauge I believe)
Battery
Alternator
Starter
Positive Power Cable

Brake Booster and line have no leaks
did a vacuum test at the brake booster, holds pressure perfectly with no loss after a few minutes, and immediately had pressure on first pump of the tester.

there are no bad wires on the harness that are pinched, cut, or bare.

getting low 20's for MPG's (about 20-23)
swapping the fuel injector didn't solve anything either...

I know it is Timing/ignition related.

when the ALDL is jumped it takes about 15-20 seconds of cranking to start the engine when cold. when not jumped it takes about 1-3 at cold

with ALDL jumped the engine sounds more throaty and has a lower tone to the exhaust, obviously this is due to not having the computer advance the timing.

swapping to a remanufactured ECM didn't help, nor did any of the ECM's I have in my parts collection...

so the computer is not in the cards...

from all the help folks have given me I believe it to be in the Ignition area with the Crank Sensor/ICM/Coils/Harness/grounding of ICM

after all the work and trouble shooting I still can't find the source to this invisible but noticeable gremlin....
anyone care to come in person to help me?
gas cost is on me of course.


In the mean time I'm still driving it (or trying to...lol), and finishing my 1987 GT Project which is literally 1 part away from running.