HELP! NO INJECTOR PULSE,...non running 96 suburban tried everything

[exp500]

How many plugs on your computer/ECM? 5 correct? That is 96 only.

 

[corbin dallas]

I am not sure but the problems you described fit in with a bad icm

i replaced the ICM with a known good one,..NO change. still nop injector pulse at the injectors. so its not the ICM.

 

[corbin dallas]

How many plugs on your computer/ECM? 5 correct? That is 96 only.

yes 5. white black red blue and the small square one. 96-97 only

 

[Doubeleive]

i replaced the ICM with a known good one,..NO change. still nop injector pulse at the injectors. so its not the ICM.

it appears I wasn't too far off track, pulse comes from the ecm but icm also has something to do with, maybe check the injector harness and be sure you have a ground that has been a rare issue before on (gmt800's)
maybe this OLD thread on another forum may help?

No injector pulse?

www.gmtruckclub.com

 

[east302]

Pinout for a 1998 5.7L attached. Alldatadiy would have it, but they went up on their subscription cost so it’s not as much of a bargain as it once was. No guarantee that it’s the same for 96, but maybe close enough.

Did you set the CMP Retard (zero degrees at 1000-rpm) following the distributor replacement? That usually throws the P1345 code, but since you had it before I’d have said a distributor issue or timing chain problem.

Injector harness at intake:

 

[corbin dallas]

I have not since I would suspect it would have noting to do with the harness to injectors not producing a ground to fire the injectors. am I wrong to assume that? i found a test procedure on her for icm,..but I think I have another one I can swap in and see. i will get back to you guys. thanks

i tried a known good ICM and coil,..still no injector pulse.

 

[exp500]

A quick search showed downloadable pdf factory service manuals on ebay for $30 or so.
Search also found a few about 150 meg size free download. Suburban/tahoe/pickup will all work for this issue 96 only. 97 up computers 4 plug.
I still think you have some anti-theft, does it use a chipped key?

 

[corbin dallas]

A quick search showed downloadable pdf factory service manuals on ebay for $30 or so.
Search also found a few about 150 meg size free download. Suburban/tahoe/pickup will all work for this issue 96 only. 97 up computers 4 plug.
I still think you have some anti-theft, does it use a chipped key?

no chipped key. just old flat metal key. no antitheft warning light anywhere in gauge cluster. owned the truck for many years. no anti theft. not even a key fob. just single ignition key

 

[corbin dallas]

View attachment 353436View attachment 353434

View attachment 353435

Pinout for a 1998 5.7L attached. Alldatadiy would have it, but they went up on their subscription cost so it’s not as much of a bargain as it once was. No guarantee that it’s the same for 96, but maybe close enough.

Did you set the CMP Retard (zero degrees at 1000-rpm) following the distributor replacement? That usually throws the P1345 code, but since you had it before I’d have said a distributor issue or timing chain problem.

Injector harness at intake:


View attachment 353437

wow

View attachment 353436View attachment 353434

View attachment 353435

Pinout for a 1998 5.7L attached. Alldatadiy would have it, but they went up on their subscription cost so it’s not as much of a bargain as it once was. No guarantee that it’s the same for 96, but maybe close enough.

Did you set the CMP Retard (zero degrees at 1000-rpm) following the distributor replacement? That usually throws the P1345 code, but since you had it before I’d have said a distributor issue or timing chain problem.

Injector harness at intake:


View attachment 353437

well like I said it used to run even when i had the p01345 code. and the timing was crazy,..like 28 degrees. and got a new distributor to fix the problem,..and it didnt. i checked any play in timing chain and none at all,..it would start,..skip stumble and sputter right after startup and smooth out 100 feet down the road hot or cold. then one day it sputtered up the driveway and just dead. no injector pulse,....so if i can get it running again i will have to reset the distributor to zero,...i didnt do that when i installed the new one,..but it stopped running before i had the chance. thanks for the diagrams,...i will get back to you guys when i have more results!!! thanks

 

[exp500]

Check for spark, check for signal from crank sensor.