2007 230 ZR-6 surging while under power

[sstexan]

Guys,

I just put my boat in the water for the first time this year. Last week, I just had the boat serviced and he changed the impeller, engine oil, tranny oil. It idles great and starts with no problem. I used the blue stabil(ethanol) in the fall and stored it with a full tank.

I noticed while under power the motor is surging a little. It is almost as if someone is moving the throttle back and forth. It seems to accelerate just fine as well. It is only happening intermittentantly. We blew through a half tank or so yesterday. I topped it back off and it is still doing it. I also am noticing exhaust fumes a little more than I used to. It is not smoking at all. It just has a rich smell to the exhaust.

I was thinking two issues:

1. Bad fuel
2. Fouled Plugs- never been replaced the boat has 315 hours.

I am thinking that we should burn through the entire tank and then replace the plugs and put fresh fuel in.

Any other ideas I should look for?

Thanks,

sstexan

[AirTool]

Someone is going to suggest pouring some "mechanic in a can" or seafoam or some other non-fuel crap in ....I wouldn't do it.

If you think the gas is a problem, can you siphon it out? Or at least have and blend with a half tank of new?

I doubt it is the plugs.

When was the last time you changed the FCC filter?

[sstexan]

The thought of disposing 62 gallons of gas kinda seems like a tough idea. I think i will just nurse through this tank and see what happens... It has not stalled once, so hopefully we will be good with the family...

The FCC was replaced about 30 hours ago last summer.

[tonygalo08]

Check engine light on? Plugs should last 500+ hrs. Most likely a fuel issue.

[TRDon]

Is it at a certain power that it will surge. My 03excal will do that if the perfect pass is on and it is too low to be in range to take control of the speed. If I turn off pp control, it won't do it.

[sstexan]

The PP is off when the engine is surging. The check engine light is NOT on and all gauges are reading normal. Over the course of a day on the water and about 1/2 to 2/3 of a tank, it probably happened 4-5 times for a few minutes each time. It seems like it was going to die, but it never did. It starts without any problems and it idles like a champ. When I filled the tank in October, I put in Stabil ran the engine for about ten minutes to make sure everything was in the fuel system.

I am now thinking I should replace the FCC. Is this something that should be replaced every year? I had it replaced last year.



Thanks,

sstexan

[kaikane]

Sounds like a fuel filter issue and/or some bad fuel. Would suggest throwing some octane booster in your tank, running it out the tank as low as possible, then changing the fuel filter. PCM (GM) motors are notoriously touchy to pressure drops and or low octane fuel. The ZR6 is a higher compression than the 343 if memory serves making the octane rating much more important.

If that doesn't solve it, I would clean the injectors with an intake fogging treatment and not suggest running injector cleaner in the tank.

[Nautiques_NZ]

You may also want to replace the small inline filter before the FCC, Some boats have them and some dont, they are prone to blocking and causing the low pressure pump to not keep up with the demand from the high pressure pump, but it has to be pretty bad to make the engine die. part # R080024 or R080024A, if fitted should be easily visible by lifting the cockpit floor.