here is the problem my 2.8 firebird has decided to eratically shut off no pattern to it at all ill be driving and it will die and then come back on and ill start it start to let the clutch out it shuts off then when i start it it idles erattic up down up down the evens out my thought is either vacum leak or cloged up fuel filter it dosent do it all the time though it happens under all conditions so any thoughts would help out and its not the iac i replaced that yesterday

 

Have the ignition control module tested, and also the pickup coil in the distributor.

 

the coil is relatively new but ill try a different one and the hei module usually just die dont they ive never had one act up they always just stop working right but ill try a different one in there thanks for the idea though

 

HEI modules have a lot of heat related problems as they age. Sometimes they will just stop working, but other times they act up first. For example, when my module went bad I was driving a long, and suddenly the tach dropped to zero for a split second every 10 seconds or so and the car would stutter. It got worse and worse until the car stalled. Then, it would start , but die right away. After letting it cool for about 20 minutes, it started up and made the trip home.


Also, check the fuel pressure when it dies.

 

And make sure you are checking the pick up coil inside the distributor, not the ignition coil outside...

They go bad a lot too..