Hi guys. My 90' GT 5spd has about 94k miles on it. I recently did a tune up: MSD coil/cap/rotor, taylor wires, double plat. plugs, oil &filter change, two new BOSCh 02 sensors. Also the car has dual 12' e-fans, and a 3row radiator with a 160* thermo.

In the morning even if its warm it's hard to start. It starts on second or third try, but you have to keep your foot on the gas to keep it running. After about thirty seconds you can let off and it'll idle. It idles rough at about 650-700rpms. Then after 5minutes or so it idles up to 900. Sometimes at idle (stoplight, stop light, drive through) it flucutates between 900 and 1100.

I have cleaned the throttle body with AMSOIL powerfoam, and removed the IAC and sprayed with powerfoam. However it didn't improve the hard to start in cold, or idle fluctuating problem. Some freinds have said to soak the IAC in carb cleaner (comes in gallon container with basket) over night to see if it helps. However I dont know how it will affect the electronics.

Are there any suggestions to what I can change to fix it?

 

FUEL PRESSURE

 

replace the IAC