Hi,

Does anyone have a 502 MPI Magnum that would run about 1500rpms when first started? After it heats up and runs a bit it idles ok. I was thinking there was an isse with the IAC. I hear a "shisshing" noise while this is going on. I'm hoping it's not metal contact but no oil loss or anything.

Thanx

Did you by any chance add a aftermarket flame arrestor? If you did sometimes they will hit the throttle linkage and make it idle high because the linkage will not go all the way back.