I have a 505 TPI in an 88 Iroc, the car likes to chug, run at half power, randomly die, and overheat easily.
Things I'm doing are:
New heated 02 sensor for the longtube headers
Full tune up

Also my car is a 1988, but for some reason it has a MASS air flow sensor AND a MAP sensor installed?? Yea...

 

sounds like theres a lot possibly wrong. we need more details. does it smoke, use oil, use coolant? what else is done to it. according to your other thread you wrecked it

 

It burns no oil, it ran like this before the wreck, it doesn't tick, it runs great till it warms up usually. does not use coolant.

 

i would start with the timing and go from there. there could be some sensor issues, a broken or inop coolant temp sensor could cause a few issues by telling the ecm the engine temp is -40. does it run rich, normal, or lean? there could be other issues as well, but lets start off with the simple

 

a 505 hugh? thats a big tpi

 

Check the throttle position senser. I had mass airflow problems for a long time.
My senser was set open too far. I have an 86 but I think 88 has the same tpi.

 

are maf sensors supposed to glow??

 

during the clean off cycle after shutting off the key, that is normal. during operation, im not sure