mid rpm range knock????

[bimmerkarl]

shortly befor I left for deployment I decided to service my '92 vert. this included spark plugs,rotor,cap,oil change, and a valve adj. soon afterwards the car devoloped a rough idle and a knock in the rpm range of 3k-3.7k. a week later I left for deployment.... since returning two weeks ago I have put 1,000 mi on the car with the same symptoms...could the knock be in the head..? or the bottom end :-( maybe its a elect. problem causing a lean mixture,therefore producing a knock?? anyone with a similar problem???

[TwoJ's]

Are you sure you're hearing detonation? Could it simply be hesitating at a certain RPM? And is it doing this only when you're under high load?

[rcko]

due the fuel filter and clean the injectors... that helped mine. guess it was starving a bit at load.

[Stevie30]

Check valve adjustment. Likely suspect!!

[StereoInstaller1]

I bet it is a rod knock.

But, I am a dick, so just go R3V it up to about 7K and sidestep the clutch.

Post pics of the carnage, please.

Luke

[StereoInstaller1]

Oh yeah...and carry a bag of kitty litter in your trunk.

[bimmerkarl]

the noise occurs even when not under load. I did discover while cleaning the engine bay today that the little square black cover on my MAF has become unglued. possible contamination to the potentiometer inside??? could cause a false airflow signal?? and in turn dick-up the mixture. my spark plugs were carboned upon removal. and after only about 2,000 miles on them.... I will change the fuel filter though. since it will need to be done anyway and I will have the car in the air tomorrow to replace my clutch slave cyl.

[StereoInstaller1]

GL man...hope I am wrong.

I was under the impression that the M20 won't run at all with the AFM unplugged.

[bimmerkarl]

not unplugged, just the little cover fell off. and I did discover a pretty nasty crack in my intake boot.......which most definately caused a jacked-up idle. being that the crack was right in front of my idle control valve.... does any one know where to purchase an aluminum intake boot replacement????????

[blueapplesoda]

I doubt it, you'd have to get the intake pipe made unfortunately.