2001 LS1 Firebird hard to start

[bull1112]

I took it into a local shop after replacing the battery. The engine is turning, good fuel pressure, but we aren’t getting spark. The coils are good, but it hard to test because after about 5 minutes if troubleshooting the car will fire up. No codes and it will run fine. It will continue to start most of the day after that with no problem. The shop is thinking it could be the computer, but says they’re back ordered at local dealership. Any thoughts? Should I try another shop? I’m happy to try to swap a PCM myself if that’s the issue.

[SMWS6TA]

Possible bad grounds.


If it was the ecm it would not run at all.

Also could be a VATS issue too.

[bull1112]

Possible bad grounds.


If it was the ecm it would not run at all.

Also could be a VATS issue too.

I suggested the bad ground as a I had that issue once before, but in that case it caused the car to misfire bad under load. Regardless, I hope they check it before giving up.

I’m inclined to agree with you about the ECM, hence this posting. It also doesn’t make sense to me that the problem would go away after the engine has started and ran for a little while. After struggling to start the car, once it does fire up, I can run errands all over town, shutting if off and cranking the car back up without issue.

The VATS is an interesting idea, but wouldn’t that prevent the engine from turning? Anytime I’ve had issues with the key not making a good connection for whatever reason, the engine wouldn’t even try to turn.

[pajeff02]

+1 on a ground issue. Also, check the connectors at the PCM (sometimes the pins have issues) and VATS remains a possibility. Just for giggles, do you have a spare key to try?

[joesurfer]

Also crank sensor can be an issue

[bull1112]

Hey all - turned out the issue was the relay to the ignition. Swapped it with the relay to the starter and the engine wouldn’t turn. $10 fix in the end!

[carlofm]

Had the same problem, but the issue was the starter.