Hesitation Problem

[1998CanadaNautique]

When i'm running my boat just about wide open, it will die for 1/2 a second and then keep going. I have a GT-40 EFI. Any ideas on what it could be.

[surroundsound64]

RE: Hesitation Problem

Is this when you first hit the throttle or after you're up to cruising speed? If it is when you're first giving it gas it is probably a fuel starvation problem. If it is happening when you're already up at speed it is probably an ignition problem.

For problem one, check the fuel filter and other simple thing. For #2, check the spark plugs, plug wires, distributor cap... Maybe that'll help.

[1998CanadaNautique]

RE: Hesitation Problem

It happens when at crusing speed around 40mph.

[surroundsound64]

RE: Hesitation Problem

Sounds ignition related. I assume you have electronic ignition?

[1998CanadaNautique]

RE: Hesitation Problem

Yes I have EFI. What are some things I should try to fix it.

[surroundsound64]

RE: Hesitation Problem

I'd probably first start by taking the spark plugs out and taking a look at them. Clean them with some carb cleaner and a soft wire brush. Or you could just replace them. Then gap them before you put them back in. You'll probably have to check with the dealer (or others on here probably know what the proper gap for them is.)
Inspect the spark plug wires for any chafing or other spots that could possibly be shorting. One trick I have used on cars before to see if the wires are shorting is to run the engine at night with no lights on and look for electrical arcs. I doubt that will work in this case since it's not a constant miss fire, but maybe in the future it'll save you some time and frustration.
Then pull the distributor cap off and look for any carbon lines or other abnormalities.

All that is pretty much a shot in the dark though... your problem could be caused by a number of things... but based upon the information you have given I'd start there.

[1998CanadaNautique]

RE: Hesitation Problem

Here is all the stuff i have done to it. I changed plugs and wires, new cap and rotor, new relays. Cleaned all the screens off. New fuel filter. And it still does it, any other suggestions?

[bchesley]

RE: Hesitation Problem

There is a module in the distributor that can go out and start intermittingly. My local dealer had a boat in last month that did this. If I remember correctly there is really no way to check for this. He had a spare distributor and dropped it in and it worked.

Brad