I have an 86 SVO Mustang(2.3ltr. Turbo) It's idling at nearly 2500rpm's but will idle normal when i take the rear breather out of the valve cover.....there is a massive amount of vacuum in the valve cover(it will suck your finger right down into the breather hole) Any clue what in the hell is causing this? I have went through all of my vacuum lines and everything is good. Take note, when i parked it for the winter season i did not have this problem but now that nice weather is here i got it back out and it is doing this. I am totally confused with it! Any help would be greatly appreciated!

 

try posting this in the v6 & 2.3, turbo section


also post some pics

 

is the vacume form the valve cover or the hoes going to the valve cover?


btw that should be your pcv valve.

 

Use a Motorcraft PCV valve, that should fix your problem