GOSH its been at least 2 years since was last logged on here.. anyways I have a 91 fc n/a that has a vac leak. any ideas where i should start looking? the car starts up fine hits the 3k warm up then drop to 1.5k for about 4 seconds then dies. if i hold the throttle down at 1k the rpm needle jumps up and down. folks have tould me before that its a vac leak. so i hope ya fc wiseguys could help me with it.

 

The easiest way to find a vacuum leak is with carb cleaner. Have your car running and spray carb cleaner on vacuu hoses and gaskets that may be leaking. if the sound of the engine changes or the rpm raise or lower you found your leak. Also your injector seals may be leaking.