www.iFourWinns.com

Starting last summer, I began having some difficulty on hot starts. Cold statrs were perfect, but stop for a while somewhere and turn the key and it would just crank. I had to give some throttle input to get it ruunning and feather it for 5-10 seconds until it levelled off and then everything would be fine. I have changed the Throttle Position Sensor, Idle Air COntrol Valve and the cap and rotor. Plugs and wires were checked last year when I changed my exhaust and he said they were perfect. Problem is still there and seems to be getting progressively worse. The boat runs like a Swiss watch, but busts my stones sometimes on the start. I ran into a friend last night and he suggested changing the fuel lines because they deteriorate over time. Any suggestions? 2004 Vista 268 with 5.7 GXi FWC with 400 hours. Thank you.

I would first put a pressure gauge on the fuel pump. It maybe dropping off pressure when it gets hot and when you shut it off, it cannot build it back up fast enough to catch it at idle, were as a little thottle helps.
Second thing is the timing. A little too much advanced will do that if your engine is not at 100% compression, which if it's used it is not.

There might be other things, but these are two that don't cost anything in parts to throw at it.

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1992 Baja 38 Special Twin 502 Mags

03 Stingray 3.0
88 261 Liberator 460 King Cobras
95 Bayliner 1850 3.0
77 Fiber Form 20ft 350/385hp
70 Wescraft 1800 SS 455 Jet

Lead, Follow, or get the Hell out of the Way!

Does the GXi mean its Fuel Injected? If so, Id suspect leaky injector(s).

Update: I am still trying to nail down this problem and think jammer may be on to something. Compression is good (150's), fresh starter and tune up. It is definitely a fuel problem. If I use the boat and then shut it off and let it sit for ten minutes or so, and go to start it, it is clear there is too much fuel. You can smell unburned fuel under the swim platform. I play with the throttle for a few seconds, burn off the excess fuel and I'm good to go. If I shut the motor off immediately after burning off the excess fuel, I can restart the motor with no issues as many times as I want (no time for leaky injectors to dump fuel into the pistons?). Let it sit for ten minutes or so and the problem is back. A computer has been on the motor and it is showing no codes. 500 FWC hours, never been stranded, just this elusive issue. I'm thinking leaky injectors. Should I just replace all of them and be done with it? Anything else that could cause this sporadic problem?

vapor lock. Run the blower at slow speeds and idle at all times. problem will go away.

If it still happens but not as bad, insulate the fuel lines

My 3.0 did this bad

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1981 Columbia 8.7
2015 Yamaha FZR - 87mph - sold
2006 Yamaha GP1300R - sold
2003 Chaparral 215 SSI - sold
2009 Stingray 195CS - sold
2000 Four Winns H180 - sold
1976 O'day Daysailer II - sold
Rick's Four Winns H180 Mods/Upgrade Thread

Your symptoms don't sound the same as mine but if you think the problem is fuel related and you have a 2004 GXi that uses ethanol laced fuel, I would look to see if paint from the fuel pump assembly is clogging the screens in your fuel pumps, fuel pressure regulator screen or it might have got into your injectors. The area you want to inspect for pealing is where the fuel filter attaches to the fuel pump assembly.

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2004 Vista 298
Twin 5.7L Volvo Penta GXi-E

Ric, thought that only happened with carburated motors. And the hatch was open the other day when it was doing it so there was no heat build up.
@ noexcuses: I have read about those issues, but I would think that would cause a fuel starvation problem. My problem is too much fuel at start for second and subsequent starts of the day. Thanks to you both.

Question, I don't know anything about injectors, but it seems the prices are all over the map. And how many do I have? One for each cylinder? or less?

Alanurt, in your update you said too much fuel from what you observed. I'd steer away from leaking injectors. The reason I say this is; the odds of all 8 injectors going south at the same time is astronomical. One or two, maybe but she'd still start and run lumpy for a little bit.

I'd throw a CTS (coolant temp sensor) at it. Cheap enough and easy to do. The ECM relies primarily on CTS input on start up for injector pulse width. If the CTS is telling the ECM that it's colder than really it is, the ECM will command the injectors to go much richer than needed. About the same as having a choke sticking closed when starting. The reason it runs well until it is shut off, would be the O2 sensors are telling the ECM the engine is running too rich and the ECM leans it out accordingly.

A bad CTS wont throw a code for being out of range either. You can have your tech look at the data stream for a pile of money to confirm it or for about 30 bux throw one in yourself. It's close the the thermostat housing and takes about 5 minutes to change with a 19mm socket.

John

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07 Azure AZ200,
Previous boat,
95 278 Vista,
And a lot of others.

Ontario, Canada

You have one per cylinder, I would get them cleaned and tested before replacing them.

http://www.injector.com/injector_service.html

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2004 Vista 298
Twin 5.7L Volvo Penta GXi-E

If all the fuel diagnostics check out, you need to consult the Volvo Penta manual for testing the pickup coil in the distributor, the ignition module and the ignition coil for fail when hot.

I can easily see the ignition module flaking out when hot - when they do, they fail 2 different ways: 1.) No spark, 2.) No advance. That could explain your hard hot start problems.

There are test procedures that are relatively simple of you have a multimeter.

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1997 Four Winns Vista 278
T - 4.3l EFI
Kohler 4esz Genset
379 hours as of 8/8/21