500efi
 

when i start my engine i get a high pitch noise that sounds like a buzzer in the engine compartment ...ive checked for vacuum leaks ..to no avail motor runs great just drives me nuts t ohear the noise if taken off the belt just to see if it was rotational ..and its not..maybe a pcv issue ..

IAC Valve???
does it go away when warm?

Fuel pump???

Often if you get a vacuum leak from the manifold it will cause the IAC to close down too much in an effort to keep the idle down within specs. When the IAC closes real tight it makes a buzz or whistle noise. There is a port on the flame arrestor side of the throttle body for the IAC. If you stick your finger on it and the buzz stops (engine will die if you hold it too long, or maybe not if the leak is enough) then you have to look for a vacuum leak, which is usually the o-rings between the upper and lower manifolds.

So after checking iac and pulling plenum I have found what I believe to be 2 orings not sealing ...... I ordered a set of orings today so hopefully I will have them by tomorrow and once it is back and running ill be able to verify the fix .. Thanks for the help

oring was deffinatly the prob after replacing all 8 motor runs great