I have a problem with my 94 N/a. The car starts and idles around 1200 to 1500, then as it warms up it drops to about 800, yet the RPM swings slightly up and down. It drives fine, eventhough sometimes you can feel a little loss of power, but it is almost unnoticed. Then, after like 15, 20 minutes of driving if I restart the car again, or even sometimes stopped, out of nowhere it rives high, to 2000 if on park, or 1500 if stopped but on drive and the car becomes very hard to drive. I replaced:
EVR, O2 sensor and the fuel filter, put fuel injector cleaner, tested the MAF and the TPS, put all new belts all around, cleaned the air intakes twice, and checked for vacuum leaks and still can not find the problem. Does anyone have an idea what could it be?? please help.

 

Welcome to ZDriver!

Have you pulled the ecu diagnostic codes?