Hello. I recently replaced the head gasket on a stock 93 eg automatic. When I had the intake manifold off it was really dirty in the runners so I sprayed carb cleaner into the manifold. After I put everything back together it fired right up but immediately had a surging or hunting idle.
The idle surges before and after the car is warmed up.

Things ive tried to fix the problem:
1. bleed the coolant
2. took off the intake and plugged the lower hole in the throttle body- which didnt change the surge. I still took off the FITV (Fast Idle Thermo Valve) and adjusted the plastic screw all the way down just in case.
3. checked the throttle cable to not be too loose of too tight
4. all vacuum lines appear to be on

Any ideas on what I should try next? Any help would be greatly appreciated! Thanks.

 

check the pcv valve and hose as these can be a sure cause of hunting/surging idle. Usually it's a result of a vacuum leak somewhere. Get some EFI cleaner and check all the hoses. Spray and check for a relaxation in the idle.

 

Did you place your finger over the upper hole leading to the EACV?

You may also want to clean the air port of the EACV with some carburetor cleaner.

Is the CEL ON?