PDA

View Full Version : Need help - engine wants to stall when transmission engaged



Donzi LG
05-10-2007, 01:11 PM
Hey guys, I'm hoping some of you can point me in the right direction regarding my engine stalling or almost stalling when I engage the transmission in forward or reverse. Here's the pertinent information:

2001 MX 6.2 MPI, 89 hours

Presently 1/2 tank of fuel from last fall; Stabil was added before winter storage

Last Saturday was initial run of the season; 1 hour cruise and boat performed flawlessly, used between 1/8 and 1/4 tank of fuel

Last night went to head out after engine warm up and boat sputtered and almost stalled as soon as tranny was engaged. Got it back into the slip and let it idle for a while. Boat idles normally but when I rev it up in neutral and it returns to idle speed it sputters and stalls or almost stalls. When it almost stalls in that scenario the engine sputters and nearly stalls then RPMs surge a little and almost stalls again and this repeats a few times. The boat will fire up and idle just fine.

So I hope some of you can point me to where to start looking for the issue. Do you think it is a fuel problem or could it be some kind of sensor malfunction? Would a clogged fuel filter cause this behavior or would the boat idle like crap also if that was the problem? I admit I'm pretty weak in the diagnostic dept. so I thought some of you can provice some advice. As always, thanks in advance for any help you can give.

John

MOP
05-10-2007, 01:47 PM
I am pretty sure you will find it in the shift interupt adjustment or maybe being a 2001 it may need a drive end shift cable, if the cable is starting to drag it will hold the interupt to long and kill the engine.
Second idea yes it could be a fuel issue, pull the canister and pour the contents into a clean container, see if you have any discolored stuff in it.

Phil

Donzi LG
05-11-2007, 10:28 AM
Thanks Phil, I'll check things as you suggest. Hopefully it won't take too long to resolve, I gotta get out there!

John

glashole
05-11-2007, 10:42 AM
just a quick note

everyone has different methods of storing their boats

I personnally fill the tank then add a fuel stabilizer

when the tank is full there is less of a chance of condensation forming in the tank and causing problems the next year :)

In my opinion I would change the fuel filter and fill the boat up


shea :)

Dave_N
05-11-2007, 11:05 AM
It's not a shift interrupt issue. It's got to be a Bravo drive. They never put the 6.2MX in front of an Alpha. I'd bet you have an IAC failure. It's very common on these engines.

The IAC (Idle Air Control) valve is controlled by the engine computer to maintain the desired idle speed and prevent stalling on sudden throttle closure. When the IAC fails, it should set a fault code and soft alarm, but not always.

Dave