Motor Gurus,

I have a '97 454 Mag MPI. Occasionally it will stall when I bring it back down to an idle. It doesn't happen when I come off plane. Just when I am idling and I goose the throttle a bit and then bring it down. I don't think a MPI motor should ever stall. What do you think the problem is?

Thanks,
Dave M.

you might try to unhook the battery for a few minutes to relearn the idle, if that dont take care of it your idle air control motor might need to be taken out and cleaned, you might also have some codes stored, if you know someone with a scan tool that would be the best place to start, good luck . Mark

I thought I heard on this board somewhere a while ago that some of the ECU's were not programmed right from Mercury and They would re-program them to cure a similar problem. Anyone know more????

RayPanic is right. There is a problem concerning a stalling condition with stock Mercruiser c.p.u.'s. There is an updated version that should clear up the problem. The last time I checked for the updated version ( I think it was around September) there wasn't any available from Merc. So, my dealer put me on his waiting list. I haven't checked in with him so far this year to see if it ever came in.

Of course this doesn't mean that this is the problem. I too would start by cleaning out the IAC motor, and scan for codes. That might lead you in the right direction.

Thanks for the info guys. The strange thing is that last fall my coupler went out. The motor was removed, coupler replaced and motor reinstalled. I never had this problem prior to that situation.

Where is th IAC? The motor was sitting for a couple weeks out of the boat partially disassembled. They also had the heads off to be reconditioned. Could this be related? Otherwise, the boat seems to run fine except for the occasional stalling.

I am still under warranty so I will be taking it to a Merc shop.

Dave M.