daniel-c

we have a couple of brand new motors like this, our problem is that the stbd motor idle is oscilating between 900 & 2000 rpm, ...can somebody help us please..

Dave_N

Any trouble codes? My first thoughts would be TPS or MAP sensors, but it could be other things. Hard to tell with limited info given.

Dave

Ted G

Might have the idle control valve sticking. Should be easy enough to pull it and clean it to start.

mjb

my 502 mpi did the same thing. I replaced the IAC valve, reset the TPS to 0% at idle and set the IAC to 35-40 counts. That cleared it up and it idles fine now. I may have been able to get away with just cleaning the IAC but it wasthe original valve with about 450 hours and a new one was only $75. Hope that helps. MJB

bobbarker

if the motors are fuel inj. check the idle sensor on the throttle body