I have a 89 L98 TPI, Car has 73,000 original miles, you can see in my sig I have a 383 and a fresh 700r4 waiting for install, but until my financial situation becomes a little more stable im dealing with what I have now.

My problem is when the car has warmed up the engine RPM's rolled almost like its got a cam, but its not regular like a cam, now I do have a mild cam and exhaust and a couple other high school bolt ons. I know its something to do with the TPI because when I unplug my IAC it runs fine, obviously i thought it was this sensor but after replacing it i still have the same problem. Also while i had the throttle body off I cleaned it thoroughly and obviously that was not it either. So I am stuck. And for background the problem started after I left the car sitting for three months, the battery had died and I had to jump it, since then it just runs like pooh at idle, sometimes i think it affect upper rpms as well but because i didnt drive it much before the problem i cant really tell if i have lost power... PLease help.....

 

Why cant I get any help, my tpi problem just is going away, dont know what to do, I checked for vac leaks and still no, im so lost anything would help.

 

If the car had a dead battery, then the ECM probably just needs to relearn the idle. Have you driven the car much?