6.2L MX MPI Stalls when shifting out of gear

[nola mike]

Same mechanic that installed the transom plate, gimble and engine. The cable is SEI.

Where should I be checking for binding?

just disconnect it from the plate and see if it's smooth.

 

[Scott06]

At the beginning of the season, I had my boat re-powered with a used 6.2L MX MPI engine. Part of this was also a new transom plate, gimbal, lower unit shift cable and bellows.
However, a problem I have been running into is that the engine stalls about 75% of the time when shifting from gear into neutral.
Im assuming the new lower shift cable might be out of adjustment?
Maybe the upper shift cable from controls needs to be replaced?
Any advice would be greatly appreciated!

What ECU are you using for this engine ? I didn't think they offered 6.2 MPIs with an alpha (shift interrupt) compatible ECU.

 

[helix757]

What ECU are you using for this engine ? I didn't think they offered 6.2 MPIs with an alpha (shift interrupt) compatible ECU.

I believe it’s using an Alpha ECU, but will have to double check.

I believe it is wired to ground the coil per this screenshot’s instructions.

 

[Scott06]

I believe it’s using an Alpha ECU, but will have to double check.

I believe it is wired to ground the coil per this screenshot’s instructions.View attachment 411623

There is no alpha ecu for a 6.2 mpi, as mentioned in the screen shot you have to do a workaround to get a bravo ecu to work with an alpha drive.
if it’s wired like that then lit would make sense the lower shift cable is dragging and triggering the switch.

was that screenshot off the marine engine forum?

 

[Scott06]

Same mechanic that installed the transom plate, gimble and engine. The cable is SEI.

Where should I be checking for binding?

As mentioned above you should be able to take two fingers and move the shift cable in and out of gear. When I did my bellows 2-3 years ago I also replace the bushings on the swiveling shift shaft in the bellhousing. the upper one was quite seated and put some drag on the shift lever that the cable actuates. I could manually get it in and out of gear by pushing on the shift cable but it took too much force. Easy way to tell if the cable back to the drive is ok or you have an issue at shift plate.

if you paid someone to do work this and the cable doesn’t shift easily I would take it back to them

 

[alldodge]

What ECU are you using for this engine ? I didn't think they offered 6.2 MPIs with an alpha (shift interrupt) compatible ECU.

Have to agree with you, I have not been able to find an ECM for a 6.2 that uses a Alpha drive

 

[helix757]

There is no alpha ecu for a 6.2 mpi, as mentioned in the screen shot you have to do a workaround to get a bravo ecu to work with an alpha drive.
if it’s wired like that then lit would make sense the lower shift cable is dragging and triggering the switch.

was that screenshot off the marine engine forum?

Roger that about the Bravo ECU.

Could you clarify your latter point about the dragging.

Are you saying the lower shift cable is likely dragging/has resistance, and likely holding the switch down for longer than necessary?

 

[helix757]

As mentioned above you should be able to take two fingers and move the shift cable in and out of gear. When I did my bellows 2-3 years ago I also replace the bushings on the swiveling shift shaft in the bellhousing. the upper one was quite seated and put some drag on the shift lever that the cable actuates. I could manually get it in and out of gear by pushing on the shift cable but it took too much force. Easy way to tell if the cable back to the drive is ok or you have an issue at shift plate.

if you paid someone to do work this and the cable doesn’t shift easily I would take it back to them

I will check and report back.

Just to confirm I am understanding this test here, I am to remove the lower shift cable arm from the bracket, then pull/push it with two fingers, and it should move like butter, correct?

 

[Scott06]

I will check and report back.

Just to confirm I am understanding this test here, I am to remove the lower shift cable arm from the bracket, then pull/push it with two fingers, and it should move like butter, correct?

Yes exactly should move freely and easily. Would also check they routed it correctly around the wye pipe . This is outlined in the gen 2 manual #14. Speaking from Experience if routedthe wrong way it puts a tight bend in it

 

[Scott06]

Roger that about the Bravo ECU.

Could you clarify your latter point about the dragging.

Are you saying the lower shift cable is likely dragging/has resistance, and likely holding the switch down for longer than necessary?

Could have resistance that’s why the test mentioned above it should move easily in and out of gear Smoothly

 

[helix757]

Yes exactly should move freely and easily. Would also check they routed it correctly around the wye pipe . This is outlined in the gen 2 manual #14. Speaking from Experience if routedthe wrong way it puts a tight bend in it

Thank you.

Do you happen to have the ability to screenshot the diagram of how it should be routed so I can verify?

 

[helix757]

Could have resistance that’s why the test mentioned above it should move easily in and out of gear Smoothly

I will test and report back

 

[Scott06]

Have to agree with you, I have not been able to find an ECM for a 6.2 that uses a Alpha drive

Yeah the biggest engine they make with an alpha is the 350 mag mpi- 300 hp. i Think all the 6.2 s are 325 or 340hp .

prob closest way to get there is take. 350 mag alpha and reflash it for a 6.2 fuel curve

I think the work around it using a NC interrupter to cut off the signal from dist to coil or interrupt 12 v to positive side of coil

 

[Scott06]

Thank you.

Do you happen to have the ability to screenshot the diagram of how it should be routed so I can verify?

It’s the lower sketch and it goes under the rear motor mount . You can see the ear of the mount on the transom plate there. The flywheel cover mount sits on top of it

 

[helix757]

It’s the lower sketch and it goes under the rear motor mount . You can see the ear of the mount on the transom plate there. The flywheel cover mount sits on top of it

I will also verify this too — thanks!

 

[helix757]

Yeah the biggest engine they make with an alpha is the 350 mag mpi- 300 hp. i Think all the 6.2 s are 325 or 340hp .

prob closest way to get there is take. 350 mag alpha and reflash it for a 6.2 fuel curve

I think the work around it using a NC interrupter to cut off the signal from dist to coil or interrupt 12 v to positive side of coil

I think the work around you described is actually what was done on my engine, and outlined in the screenshot prior?

 

[Scott06]

I think the work around you described is actually what was done on my engine, and outlined in the screenshot prior?

Yes what was described interrupts the triggering signal between the dist and the coil, will keep coil from firing