I have a 1988 GTA with idle issues. I recently replaced the MAF sensor with the really nice Granatelli Motorsports Mass Air Flow Sensor from hawks third gen. After the install i noticed the car would misfire faintly followed by a ticking noise. Unplug the sensor and the ticking noise goes away and no misfire either. After about an hour of calibrating the sensor I have it to where the car will idle around 500/600 rpm when in drive and around 750 rpm idle while in park. Only while the car is in park and at idle 750 rpm will the misfire occur followed by a ticking sound, the misfire is not consistence and seems to be random but the more the sensor is advanced the worse it will get so i have it set to where its pretty good but not perfect. Is there a good idle zone where the car will run happy. Any advice or help would be greatly appreciated.

 

Sounds like arcing on the spark plug wires or in the distributor cap. Look for cracks in the cap and the plug boots or dirt on the plugs.