my car (89 5,7lt gta,a4)begann to die at idle and doesnt rev properly since 4weeks.i run an 160stat.before the water temp reaches 160 it runs fine.but somewhere at that point it beginns to hesitate at idle.no ses-light.no codes.sometimes it seems the engines is goin to die at idle,the ses-light goes on for just an instant moment and then,it revs itself to900rpm and runs just fine.i maintain the car good and also already replaced the maf-sensor and the o2sensor.still doing the same.

 

I also have a similar situation with a 1991 Chevy Camaro Z28 that I own. I am running a 160 thermostat and it ran ok because I had an EGR (Engine Gas Recirculation) solenoid and connector that were bad. After both these were replaced, I had it smogged and passed. Two weeks after being smog tested, it started to miss badly and I am still having this problem and plan to change the thermostat to 180 degrees and see what happens, originally my car came with a 195 degree thermostat and majority of the members here have told to switch my thermostat because it is causing an open or closed loop condition-after car warms up it still thinks it's in warm up mode. Before you do anything, did you modify your computer or make modifications to your car?

 

thanks for your reply.the computer is stock.mods are headers,ported intake etc no cam,head change.your idea with the stat sounds good to me,cus its obvious that it doesnt see the difference open/closed loop(even on the computer),but no ses-light.first i tought it could be the tps sensor,but when the engines cold,it would idle fine,the tps would either work all the time or not work all the time(if its bad).