Cascade Crew

Xophertony

my 1988 trans AM GTA with a 350 TPI is having an intermittant no start situation. only once the engine is hot. before it gets hot it will start 10 times out of ten. once it's hot it is still intermittant. it seems to be once ity has gotten hot, and then cooled off a bit. the first start of the day always works. and it always starts eventualy.

the nature of the no-start is: starter turns, Fuel flows (i can smell it after a few trys), and i assume air gets in. it seems to be sparking intermittantly, but it could be an air-fuel ratio problem too. i have no guage for that.

i have tried the following diagnostic elimination steps.
replaced ignition control module with spare. problem persists.
unplugged the IAC. replaced IAC with spare. problem persists.
unplugged the MAF. problem persists.
unplugged the EST connector. problem persists.

thats it so far. i have tried checking (using a timing light) if i am getting spark when it won't start, and now it is starting every time. it is so hard to diagnose intermittant problems.

also an FYI. by description this sounds like a heat soaked coil, but i have an ultracoil, mounted on the far drivers side firewall. it is about as far away from engine heat as a coil can get. it does not exceed air temperature when driving (well, the cars BLACK, but you know).

once the car is running it seems to run fine. no major poping in the exhaust, it does not die, it does not feel less poerfull, no bucking or sputering.

one odd thing i noticed, when replacing the Ignition module i noticed the pickup coil (new at cows last year with the rest of the dizzy) has surface rust on it. is that normal?

thanks for the help guys.

Twilightoptics · Posted: Sun Jul 12, 2009 4:37 pm Post subject:

Maybe a wiring thing. I'd be looking at the fusible links off the starter. With headers they get pretty hot and need to be routed very well.

Pickup coils will get rusty immediately. I'm suprised they aren't rusty outta the box.

Gotta just keep after it. I was under an assumption, possible wrong, that if the ECM doesn't get an rpm signal from the module, the injectors wont fire.

Next time this happens, after a few tries, put the pedal to the floor and then try cranking. See what happens.

Also, check your cold start injector. On my '85 I blew the 3 amp fuse, and it wouldn't start for shizzle cold. Sounds like the same. Maybe your injector is still pumping fuel, or leaking. So it's getting too much fuel hot, hense the smell.

Just an idea.

Xophertony · Posted: Sun Jul 12, 2009 4:53 pm Post subject:

Twilightoptics · Posted: Sun Jul 12, 2009 5:32 pm Post subject:

Might figure out if it's leaking. Unplug it from the base and swing it out and look. Pressurize the system and see if she leaks.

Could be an injector too.

popballz · Posted: Sun Jul 12, 2009 5:47 pm Post subject:

mine did the same thing, it would start fine in the morning, then not start for the rest of the day. after it warmed up, you could start it as many times as you wanted within like 20-30 min, but after that, it had to sit for like 24 hours!

my problem was the Ignition module, might wanna recheck that, might of been a bad one?

Xophertony · Posted: Sun Jul 12, 2009 6:34 pm Post subject:

well, i did buy two to keep as spares... so i'll pop in the other new one.

Xophertony · Posted: Wed Jul 15, 2009 6:26 am Post subject:

i'm now on new ICM number two. started fine last night. i'll report back in a few days if it's all-the-way fixed. Smile

thanks everyone.