Yellow_stang

I have a 88 mustang GT with full exhaust headers n back, and i have A problem but dont know what it could be i notice that when i start the car it idles like if had a 347 stroker under my hood when its just a stock 302, and today as i was inspecting my vacum lines i noticed that when i disconect the vacum line that goes to the EGR valve (the one that has the 90 degree on back of the throttle body and egr spacer.) it starts idleing normal, and as soon as i plug the vacum line back on the egr it starts idleing rough again like if it wanted to turn off but it doesnt... any help apreciated thanks...

PRO50SC

Pull the vacuum line back off while it's running. Put your finger over the line and see if you can feel the vacuum sucking. You should NOT be able to feel any. If you do, it's pulling the valve open at idle and it shouldn't be. If it is, you probably either have the supply line hooked up wrong on the egr control solenoid is stuck open.

Yellow_stang

thats exactly what it does the vacum line suck on my finger and while i have it off its idleing fine as soon as i put back on it starts idleing bad, so what did u say could be my problem if its doing that ?

PRO50SC

Come on man, re read my post above.