Hello, I have a 1993 z28. Recently I have had quite a few issues with my car. Originally it started cutting off after driving for about 30 minutes. It was very random and would happen at any rpm, I replaced my fuel filter and for a week (daily driving to work) it didn’t shut off once. This week, it has shut off about 3 times, I’m going to replace my tps later this week. Has anyone else had a similar experience? Fuel pump works perfectly fine btw. Did a pressure test. I’ve noticed it only really happens when it’s warm out as well.
only codes I have gotten are 21 & 61. I did the old school paper clip trick. I am hoping it’s the TPS or something else and not an open circuit.

 

The ignition control module (ICM) can suffer from heat soak, as can the optical module in the Optispark distributor. But both of the those should set codes if they are failing. Problem with DTC 16 for the Opti low resolution cam/crank position pulse is that it can’t set if the high resolution pulse also fails. An auto supply store can test the ICM, but they need to make sure they get it good and hot.

Fuel pump can heat soak. If the fuel gets too hot you can experience the fuel flashing to vapor on the suction side of the pump.

Did you test the TPS? Simple to do with a volt meter.

 

I have not tested it yet, I’ll probably pick up a meter today after work and do a few tests myself. I’ll get back to you later on today