2005 320 5.7L with V - Missfire

[Seapig]

Ok, then it sounds like I need to give this a try before giving up entirely. Thank you and happy boating!

If your distributor wasn’t monkeyed with or moved, it’s unlikely that you have the same issue.

 

[stephenm27]

If your distributor wasn’t monkeyed with or moved, it’s unlikely that you have the same issue.

You would think this is the case. However, the Merc video/bulletin explains that they have found mechanical wear after as little as 20 hours on the engine can result in minute timing issues that manifest as crossfire/misfire. They specifically cite timing change stretch as a contributor. I have 320 hours on this engine.

So, in the interest of eliminating potential causes, I have done some hall-effect sensor research and constructed the "camshaft position indicator" tool mentioned in the video and will perform the procedure as described. It should indicate whether I might have found the problem. If no adjustment is indicated by the process, then I know to disregard and continue my troubleshooting. Hope is all I have right now .

 

[stephenm27]

You would think this is the case. However, the Merc video/bulletin explains that they have found mechanical wear after as little as 20 hours on the engine can result in minute timing issues that manifest as crossfire/misfire. They specifically cite timing change stretch as a contributor. I have 320 hours on this engine.

So, in the interest of eliminating potential causes, I have done some hall-effect sensor research and constructed the "camshaft position indicator" tool mentioned in the video and will perform the procedure as described. It should indicate whether I might have found the problem. If no adjustment is indicated by the process, then I know to disregard and continue my troubleshooting. Hope is all I have right now .

We took it out for a test run this morning, and after a few tweaks to the distributor in both directions, I was able to determine that moving it counter-clockwise about a 1/16th of an inch resolved the intake popping entirely. It’s the best it has run in the last two seasons.

Unfortunately, on the way home, the boat was broadsided by a Toyota Tacoma at about 35 mph (he ran the red light).

Tonight, the boat is on a low boy in a local tow yard awaiting the start of the insurance process. If I had to guess, I would say it’s likely to be totaled.

I think I’ll start another thread on lessons learned today ;-).

 

[KevinC]

We took it out for a test run this morning, and after a few tweaks to the distributor in both directions, I was able to determine that moving it counter-clockwise about a 1/16th of an inch resolved the intake popping entirely. It’s the best it has run in the last two seasons.

Unfortunately, on the way home, the boat was broadsided by a Toyota Tacoma at about 35 mph (he ran the red light).

Tonight, the boat is on a low boy in a local tow yard awaiting the start of the insurance process. If I had to guess, I would say it’s likely to be totaled.

I think I’ll start another thread on lessons learned today ;-).

Well that sucks. Best of luck with dealing with your insurance.

-Kevin

 

[MAKC]

Timing was off by about a /16th
just a slight tap and it made all the diference.

shes running amazing

Did you ever find the tool they talked about in that video or just moved the timing that little bit?

 

[stephenm27]

Did you ever find the tool they talked about in that video or just moved the timing that little bit?

I made the tool from a 9V battery, LED and a resistor. Essentially, all it is is a visual tool to detect when the cam shaft sensor (a hall-effect switch) transitions from off/on.

Even with the tool, I found manual adjustment on the lake to be a better solution. I think the tool would be better if you had significant timing chain stretch, but in my case, the eventual adjustment was only 1/16" of an inch (as measured on the hvs cap).

 

[MAKC]

I made the tool from a 9V battery, LED and a resistor. Essentially, all it is is a visual tool to detect when the cam shaft sensor (a hall-effect switch) transitions from off/on.

Even with the tool, I found manual adjustment on the lake to be a better solution. I think the tool would be better if you had significant timing chain stretch, but in my case, the eventual adjustment was only 1/16" of an inch (as measured on the hvs cap).

Thank you so much!