88 2.5 Starting Issue (Page 1/1)
Erik APR 27, 04:59 PM
I have been driving my 88 coupe for work. For quite some time if I stop at a clients for more than 10 min and I go back to start the vehicle it will not start without a lot of turning over and turning the ignition on and off and finally it will catch. I hear the fuel pump relay kick in for a few seconds each time I turn the ignition off and then turn it back to start. I put my phone on the throttlebody to see what was going on when I try to start it and apparently it is not firing the injector when its turning over. So if I squirt a little starting fluid in the throttlebody it will start up and run and I can go on to the next destination. If it sets for an hour or two it’ll be fine and start up again after it cools off. I was thinking maybe it was vapor locking but why would it start if I squirt a little injector fluid into the throttlebody and then the injector will work and stay running. Anybody have any ideas as to what’s going on? I was thinking possibly I might have a weak oil pressure sensor or somethings up with the throttle injector.
theogre APR 27, 05:18 PM
ECM won't run EFI unless have good ignition.
Even have good ignition, iffy wires to ECM or ECM itself can have problems and EFI won't run.

ECM can die from heat. Cabin Temp can reach 150-200°F when parked + ECM Generates Heat and case is a heat sink.
see save https://web.archive.org/web...cast.net/~fierocave/ ECM Heat.

Also Clean/Fix all "grounds" in engine bay. Some are not grounds but labeled such in many "books" and crap connections will cause problems.
Any bolted/screwed to the engine needs cleaning then use Silicone or Permatex Brake grease to prevent happening again.
See cave, wire service

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

Erik APR 27, 07:04 PM

quote
Originally posted by theogre:

ECM won't run EFI unless have good ignition.
Even have good ignition, iffy wires to ECM or ECM itself can have problems and EFI won't run.

ECM can die from heat. Cabin Temp can reach 150-200°F when parked + ECM Generates Heat and case is a heat sink.
see save https://web.archive.org/web...cast.net/~fierocave/ ECM Heat.

Also Clean/Fix all "grounds" in engine bay. Some are not grounds but labeled such in many "books" and crap connections will cause problems.
Any bolted/screwed to the engine needs cleaning then use Silicone or Permatex Brake grease to prevent happening again.
See cave, wire service





Thanks for the response. So if the ECM is that issue why would it start and stay running when I squirt a little starter fluid in it?
theogre APR 27, 11:39 PM
Likely Because ECM hasn't taken over the Ignition Timing to start the engine.
Then ECM may try or has done that but bad ECM still won't run the injection.

Get a noid light for GM 700 series TBI. Shows injector on by flashing light.

If/when you buy ECM, save the PROM in it to move to new ECM.