need some help....

[jdm lumina]

i have a 91 lumina euro with a 3.1 in it. i've been having problems lately.

 

problem 1- car has a hard time trying to start

problem 2- when the engines get hot the rpms start to jump and sometimes cut off. when its real hot it wont even start back up. we knew it was the cat so we just put a straight pipe inplace of the cat. but the car stills runs fine when its cold but when its hot the rpms still jump around and the car cuts off.

 

im lost now. i need help. any suggestions on what the problem might be?

[Crazy K]

ignition module... or crank sensor.

[Addicted To Boost]

Could be coils on their way out too. Or ICM or CKP Sensor, like Ken said.

[slick]

Yep, i'd start by having the ICM/Coils tested. As for no restart when hot, possible bad starter solenoid. Seems somewhat common.