5.0L MPI 2002 Merc engine cuts out for no reason....

[dubie73]

Re: 5.0L MPI 2002 Merc engine cuts out for no reason....

Still pulling my hair out!
I have a mercury service bulletin no.2003-06 that suggests this could be a faulty shift interrupter switch. They mention to jumper wires on the engine wire harness and if that cures the problem then to replace engine ECM.
Anyone ever have this problem or try this?

I have also been thinking about the Idle Air Control Valve (IAC) and that being a possible problem? Anyone please help.Thanks

 

[Fun Times]

Re: 5.0L MPI 2002 Merc engine cuts out for no reason....

Still pulling my hair out!
I have a mercury service bulletin no.2003-06 that suggests this could be a faulty shift interrupter switch. They mention to jumper wires on the engine wire harness and if that cures the problem then to replace engine ECM.
Anyone ever have this problem or try this?

Your serial number is within range of the service bulletin, The test on page 3/3 should be done as everything you've described leads to this service bulletin.

Good luck.

 

[Glasply]

Re: 5.0L MPI 2002 Merc engine cuts out for no reason....

I've had this issue on MPI motors on two boats. The fuel pump has a screen on the inlet side, like a faucet aerator, plugs up with gunk and this happens. Just exactly as you describe, run all day at low rpm, dies when you throttle up. The key off/key on re-primes the system and you can run again instantly with the constricted pump. Causes a whine from the constricted pump.

Any chance you left the fitting with the screen in place when you replaced the pump that was failing?

 

[dubie73]

Re: 5.0L MPI 2002 Merc engine cuts out for no reason....

I hope they would have changed that screen at the dealer when pump was done but I wouldn't assume anything. Thanks for the info. Did yours Glasply just cut out instantly like key was turned off or did it sputter or miss?
I have had this in dealer three times and have spent way too much with no results this far so I am reluctant to return to dealer. When I told them about the Merc. Service bulletin they looked like a deer in the headlights and had no idea or even heard about it. Nice mechanics I have here..not!

Sorry for the rant but I will will sure check up on this screen as potential issue. I appreciate all feedback and leads anyone has.

 

[Glasply]

Re: 5.0L MPI 2002 Merc engine cuts out for no reason....

That's exactly how it died, like pulling the coil wire dead. There's almost always another screen on your fuel pickup in the tank, too, but it's usually a course mesh compared to the fuel pump screen.

 

[dubie73]

Re: 5.0L MPI 2002 Merc engine cuts out for no reason....

Problem solved! Finally!
I did as desribed in the Mercury service bulletin referenced above and installed the jumper wire. Boat ran excellenon with no cut outs. Pulled jumper wire out just to be sure and bamm...it died. Put jumper wire back in and no problem.
Thanks to all those who helped and I hope this may find someone who is experiencing the same same problem.

I do have one remaining question however. This jumper wire is on the shift interupter switch. And this is supposed to indicate ECM problem. Why not leave jumper wire in and skip the purchace of a very expensive ECM? What harm could be done?
Also what is this switch supposed to do? Everything is running as normal and I don't see any obvious need for this??

 

[boatguya1]

Re: 5.0L MPI 2002 Merc engine cuts out for no reason....

Problem solved! Finally!
I did as desribed in the Mercury service bulletin referenced above and installed the jumper wire. Boat ran excellenon with no cut outs. Pulled jumper wire out just to be sure and bamm...it died. Put jumper wire back in and no problem.
Thanks to all those who helped and I hope this may find someone who is experiencing the same same problem.

I do have one remaining question however. This jumper wire is on the shift interupter switch. And this is supposed to indicate ECM problem. Why not leave jumper wire in and skip the purchace of a very expensive ECM? What harm could be done?
Also what is this switch supposed to do? Everything is running as normal and I don't see any obvious need for this??

Shift interupt helps you shift out of gear, without it you will develop cable problem.

Do you have the lever and roller interupt switch or the push button one? If it's the push button one I'd try replacing the switch prior to buying an ecm.

 

[dubie73]

Re: 5.0L MPI 2002 Merc engine cuts out for no reason....

It is the push button switch. When I was messing around with adding the jumper wire we moved the shift likage in and out of gear and the switch does not get engaged. I suspect the linkage is set wrong. This could possibly be the problem also.
The boat shift in and out of gear with no problems at all with the switch bypassed.
And as I mentioned the switch is not depressed at all when the shift linkage is moved in any position.
Maybe proper shift linkage setting will make this problem disappear without the need to replace switch or purchase new ECM......

 

[Wirewheels]

Dubie,
I'd love to hear what your final final resolution was. I have this exact issue, and, like you, I'm not crazy about shelling out for a new ECM. Did the linkage adjustment resolve the issue, or did you finally get a new ECM? If the latter, where did you purchase it from?

Thanks!

 

[dubie73]

Dubie,
I'd love to hear what your final final resolution was. I have this exact issue, and, like you, I'm not crazy about shelling out for a new ECM. Did the linkage adjustment resolve the issue, or did you finally get a new ECM? If the latter, where did you purchase it from?

Thanks!

Wirewheels, I installed the jumper wire ging to the ECM and have been running like that with no issues on the shift interupter switch as stated above as I like you don't want to dish out the dollars for new ECM. Shifts no problem and have not had an issue in 2 years.