Hi all,
I'm at my wits end. Idle is bouncing from around 600 to 1300 or so in a cyclic fashion. I have cleaned (tons of crud) out of ICV and tested. O2 and ICU appear to be working. Have looked for vacuum leaks and can find none. Yesterday, while checking for vacuum leaks, I pulled the dip stick out. Lo and behold, the idle settled down at about 700 rpm and stayed there. Of course, with the dip stick out, my acceleration went to pot.
It almost seems as if the engine is producing too much vacuum - which apparently is fluctuating enough to induce the cycling idle.
Another interesting note is that there is a whistle being produced by the ICV which gets louder as you throttle the motor up. This to me suggests vacuum leak, but After a full can of carb cleaner sprayed all over, I can't find a leak.
I dont' have any test parts to verify that the tested parts are good, but they all seem to be functioning.
Does anyone have any thoughts? Motor runs great other than that.
BTW-84 325E....2.7L
Help.....