Running Issues

[Wakeman22]

So I am having running issues again. 2007 24ve with a MPI 360hp. Has the speed set and throttle by wire.

The boat acts like bad gas or plugged filter. This problem has reared itself again. Got fuel at the Marina but this has also been going on with Station gas.

Boat accelerates to a set speed but in a while will cut off or start to cough sputter spit backfire all those things. Sometimes will clean up other times not. I have put it in a power turn and let the load build and that has fixed the problem sometimes as well has just opening her up and hot dogging it. Another symptom is a slight missing sometimes while running however I do not believe this is causing the condition I am having but may be connected.

Things I have done. Changed spark plugs, helped for a short period. Fuel filter. Oil changes and battery checks. Fuel pressure is up all the time even when the engine coughs and spits. Added Seafoam, injector cleaner and octane boost. Did not cure the problem.

Any thoughts or trouble shooting tips will really help. I am hoping Mr. Forte will chime in with some advise.

[lee]

What about the distributor cap and rotor? Could have corrosion on the inside.

[IDBoating]

Why did new plugs help for a while? Does the engine foul plugs? That would be a big hint.

[Chads972150]

Yea what do the plugs look like now and how many hours are on them?? Could have bad plug wires and as stated above distributor could be bad it if it's a coil on top of plug motor as I'm not to familiar with newer boat motors and when they got what this really sounds like a coil breaking down. Could also be clogged injector most of the "cleaner" in injector cleaners gets filtered out by the fuel filter

[Wakeman22]

My next step is the cap, rotor and wires. However I still believe it is a fueling problem. The plugs were changed last year when this issue started. The removed plugs looked to be in good shape and no indication that any cylinder was fouling or acting up. I did the filter at the same time. This seemed to work for a day or so and the problem came back.

While reading other posts it seems that others have had the same issue. They change out everything and it still comes down to something in the fuel system. Could be my pump however the fuel pressure does not go down under load. I do not believe it is the plugs. They only have about 25 hours on them. The old ones went 650 hours. I will do plug wires when I find where to get some.

Does any one know about the G-Force fuel pump system and how it works?

This issue has been a problem others have had while I read other similar posts. Where can I get a computer tester for this so I can see what codes there may be?

[lee]

Where can I get a computer tester for this so I can see what codes there may be?

http://www.rinda.com/marine/diacommarine.htm

[bsreid]

We had a similar problem last season.
If it is your fuel line there is a little screen the size of a thimble on the end of the line which might be rusted or have something stuck in it, causing the boat to have to work to get gas.
100 hours later running and still perfect.
We relaced our fuel pump and all that too and no luck

[Wakeman22]

Reid your boat is a lot newer than mine but where exactly is this screen?

[Wakeman22]

Allen the tool you linked is for an OBD2 system similar to a car connecter. My boat is different. I already have the OBD2 scan tool for vehicles. But I do like the program that comes with that system. I need something like that to log in the events as they happen in real time and not just a code only flasher.

[Thegerman618]

Just had this happen on the test drive, find your low pressure fuel pump, it's on the right side if facing the rear of the boat. There is a cooler line that wraps around the pump to keep it cool, over time the epoxy that holds it wears off and slides down and disconnects the power wire, it's just a post that it clamps to. Use some zip ties to hold it back up in place if it's disconnected. Hope this helps

[The Black Widow]

I have the MP 6.0l engine and had similar issues a few years back. Thought it was bad gas for a while but ended up being the low pressure fuel pump. This is the smaller one (not in canister) with the cooling coil around it. We never did fuel pressure tests so I can't tell you what you should be looking for there.

http://marineenginedepot.com/MP/Mari...talled-Cooler/

If you have the same engine it is on the starboard side under the high pressure fuel pump in the canister. We never had to change our g-force high pressure pump but here is the link to that part.

http://marineenginedepot.com/MP/Mari...and-Cannister/

[bsreid]

I'm sorry I wasn't the one who found the problem, all I know is that it was just in the fuel line.

[Wakeman22]

Thank you guys for the input. I am out of town for a week so when I get back I will look at all the suggestions given. Thanks Allen for the links and suggestion for the computer and its use. That is what I am looking for. I hate to take things to a dealer if I do not absolutely need to. This issue has been a bear to fix. It seems I do something and it cures the problem for a while and then it comes back. I will also be looking at the distributer and associated parts.

[PaceWithGrace]

Misfiring at speed? The camp 2007 Wakesetter did that last summer. After getting it nice and hot, it would misfire like crazy at 3000 rpm. Sometimes it would rev past that and clear up; sometimes it wouldn't get past that. Turned out to be the distributor shaft that wore enough to bounce at that rpm. New shaft fixed the problem. Apparently it's not uncommon.

Sure would be nice to have a technical FAQ to record things like this. In the meantime, I hope some experts chime in here - I don't know if that's the problem here and it's a medium pricey fix - but in the future others will be able to search and find this thread.

[dilpickle]

Misfiring at speed? The camp 2007 Wakesetter did that last summer. After getting it nice and hot, it would misfire like crazy at 3000 rpm. Sometimes it would rev past that and clear up; sometimes it wouldn't get past that. Turned out to be the distributor shaft that wore enough to bounce at that rpm. New shaft fixed the problem. Apparently it's not uncommon.

Sure would be nice to have a technical FAQ to record things like this. In the meantime, I hope some experts chime in here - I don't know if that's the problem here and it's a medium pricey fix - but in the future others will be able to search and find this thread.

That would be fairly easy to diagnose by using timing light on engine while having the problem. You would be able to see the timing bounce at the affected RPM.