Hey guys I have a 92 LS Auto for which I recently swapped the engine on (from my other DA). Well my issue is that if I rev the car the idle decreases smoothly until it reaches 1k, then it drops hard till 500RPMs and slowly begins to stabilize itself at 850 (I increased it by 100). Also the lights dim bad with a regular radio system on and the car vibrates more and more every time I turn something on like the headlights, wipers or rear defroster.
As for the idle issue I have replaced both IACV and FITV and even cleaned out the Throttle Body. NOTHING!
I checked the Ground to the Negative (Battery) to Transmission and its good, as it the one from the Valve Cover to the frame.
Is there a ground on the motor itself that could cause these issues? Because the engine was swapped completely, and it had the same issues on the other car which I thought was a issue with the wiring harness, but that has been proven to be wrong!
Please help!!!