www.iFourWinns.com

For over a year now my port motor has been failing. It is extremely sporadic – it can happen after just simply sitting for days (no start). It has happened while underway (4200 RPM’s) and a stall followed by no start. I have (along with certified Penta Mechanics ) have tried numerous things – but one thing that seems to resolve is a new coil which will give me approximately 5-10 hours of clean starts and running. So obviously we have been chasing ignition. However, the other day when the engine failed I was able to see spark through a spark tester on the front right cylinder, had 50 lbs of fuel pressure at the fuel injector rails and confirmed the injectors were requesting fuel via a test light and no start. Then after sitting for 2 hours it started – however other time it runs fine sits for 2 hours and wont start. Here is what has been done to date:

Swap ECM – no change
New Plugs
New wires
New battery
Numerous coils
Cleaned and greased grounds (to the best of my abilities)
Added a separate ground to the coil itself
Confirmed alternator output voltage (14 same as starboard)
Confirmed Fuel pressure (50 lbs – same as starboard)
Changed fuel filters (many times)
Poured fuel into glass to confirm no water
Confirmed compression on all cylinders
Confirmed plugs were dry

As of now it is a complete crap shoot as to if it will start and if so how long will it run.

Any help is appreciated.

Just a thought I know you feel it's ignition but what about tank to fuel pump lines. I've heard of them being weakened on the inside and sucking closed in a bend. Ethanol eats them from the inside out

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2001 Four Winns Vista 248 by rick2752, on Flickr

I had a similar situation a few years back, engine would be cruising just fine and then just stop, the next day it started fine. I replaced the fuse/relay box and I've never had the problem again. The replacement box came with longer screws and vibration isolators which will supposedly extend the life of the box, you can Google Volvo Service Bulletin P-37-2-2 which discusses the replacement box. I've taken a look at the Gxi-F fuse box and mounting bracket, it has been changed from the Gxi-E so this might not be your issue. Have you tried new ignition relays? You could also swap the fuse/relay box with your other engine and see if it occurs on the starboard side.

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2004 Vista 298
Twin 5.7L Volvo Penta GXi-E

Change the distributor cap.
I have had caps with intermittent connectivity on some cylinders.
That seems to be the one thing you have not changed.

I actually broke down one time due to a bad cap.
Running fine and all of a sudden bogged and died. Would crank but no power. After about 10 minutes would not crank.
Next day cranked fine but as soon as it warmed up started missing and died.
Next day would not crank.
Checked plug 1 - fire.
Chassed for about an hour. Had fuel, had injectors firing. Had good coil output.
Checked plug 5 - no fire.
Checked plug 7 - no fire.
Checked plug 1 - fire.
Changed cap - no issues.

Bottom line - check all cylinders for fire - not just one. Or change distributor cap and rotor.

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The Dance II
2007 278 Vista
6.2L Mercruiser

thanks for the replies!
Rick2752: I will give that a shot but wouldn't that cause no fuel pressure at the rails?

TheDance: I neglected to list that I did change the cap and rotor - however, that is a good tip as I have only been checking one plug for spark. I will check them all

Noexcuses: I am going to give that a shot by swapping the fuse box to the starboard. Are the ignition relays in that fuse box?

I would think so, I think you have the same box as shown in this post.

http://forums.iboats.com/forum/engine-r ... down-or-up

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2004 Vista 298
Twin 5.7L Volvo Penta GXi-E