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-   -   Mercury MX 6.2 cuts out (https://www.offshoreonly.com/forums/general-q/274219-mercury-mx-6-2-cuts-out.html)

halffast 05-04-2012 04:26 PM

To the guy with the 6.2 skipping.Over time the crank position sensor that is mounted right behind the harmonic balancer may get a little too close to the reluctor wheel due to the plastic cover warping a little over time. Take a # 10 washer and place it between the metal bracket and the plastice cover to space it out apx. .020.This fixed some of our 6.2 mercs. hf...

osur866 05-09-2012 08:19 PM


Originally Posted by spectras only (Post 3661513)
Power from the battery goes through a small black 90A square fuse block onto the starter.It gets loose sometimes,all you do is tighten the nut &bolt .The ECM555 senses voltage drop and cuts the ignition out randomly.

This is what it appeared to be, tightened and been all good since. Thanks for the tip. Steve

spectras only 05-09-2012 11:39 PM

I'm glad it was a simple fix! Put a hose clamp on the main connector to the engine also!

osur866 05-10-2012 01:37 AM


Originally Posted by spectras only (Post 3684093)
I'm glad it was a simple fix! Put a hose clamp on the main connector to the engine also!

Hose clamp on main connector to motor? Not sure I follow, unless that's suppose to stop it from moving and getting loose as a result

spectras only 05-10-2012 11:36 AM

The 6.2 has two main connector/harness. One is a big round plug, power [ black ] that sometimes getting its way out.That's the one you want to put a s/s hoseclamp on tight.The blue cable [ for the ECM555] connector is more secure.

osur866 06-06-2012 06:01 PM

Ok thought I had this issue fixed but.......
I've tightend the battery terminals, connector at starter where the big fuse block is also checked main wiring harness for tight connection along with the 2 plugs on the ECM. I've hooked it up to Diacom software which gives no faults and it still sounds the alarm and the engine stalls for just a sec not enough to kill it, I've noticed today while idling around if I use the trim a lot it wants to do it more often, so I'm pretty sure it's voltage related, Ive replaced battery and the alternator is charging any ideas?? I've got both an ignition and fuel pump relay on order should be here tomorrow to swap and try, I've never noticed it cutting out past 3,800 RPM's only at lower RPM's in the idle to say 2,800 ish.

osur866 06-20-2012 12:24 AM


Originally Posted by halffast (Post 3679555)
To the guy with the 6.2 skipping.Over time the crank position sensor that is mounted right behind the harmonic balancer may get a little too close to the reluctor wheel due to the plastic cover warping a little over time. Take a # 10 washer and place it between the metal bracket and the plastice cover to space it out apx. .020.This fixed some of our 6.2 mercs. hf...

Wouldnt this show up on an engine scan as a crank sensor fault?? I'm getting no faults when I scan it, it does go into guardian mode if I'm at full throttle and then gives me over speeds codes, I'm sure it's because I'm at wfo when it has the issue, but no other codes tripped.
Replaced relays and problem still existis?? Ideas?? Anyone?

axm0z5h 10-19-2018 01:08 PM

im having this exact issue. was this ever solved. my symptoms are identical

fletchersmachine 01-19-2023 05:11 AM

Change the rotor, or check it with an OHM meter. They are notoriously bad, they loose contact between the stainless steel and brass junction. Big GM problem, most GM car dealerships are aware of the condition as bulletins have been sent to all GM service departments.

boostbros 01-19-2023 07:53 AM

i have had a few of these i just turn the dist a little bit and problem solved theres a few on here that could bring up a tech bulletin on this


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