Warm engine won't start if setting for > 20 min

[lakept]

Ok, so my 1995 GT40 engine starts cold fine, runs fine, and when turning it off briefly between one skier and the next starts fine. It is only when the boat is turned off for more than 20min do I have a problem. It will only restart after letting the engine completely cool down (over 8 hours) for it to start again.

I can easily replicate this problem over and over. Any ideas?

[NautiBrophy]

same issue

I had the same issue.

There are a lot of things that could be wrong. It could be your low or high pressure fuel pump. Could be your fuel pump sensors. There are other things that can be this check out older threads like my 99 air nautique engine issue and there are other ones as well.

http://www.planetnautique.com/vb3/sh...Engine-Problem

good luck let me know what you find out!

[teamseal]

fuel pump sensors????? Maybe fuel pump relay!!

Have seen similar problem like this I wonder if the alcohol addative in our fuel is causing a lower vapor pressure's and setting up a vapor lock situation. Try pouring cool lake water over the low pressure pump and see if that helps get the motor started.

[DanielC]

Do this:
http://www.planetnautique.com/vb3/sh...=Fuel+Pressure
And this:
http://www.planetnautique.com/vb3/sh...light=Ignition

Report back
It is important that you do the fuel pressure check when you are having the no start condition.

[AB]

You can rule the fp relays out by turning on the key and listening for the fp priming the next time you have the problem.

Sounds more like a vapor lock of some sort. Alcohol in fuel was discussed in another thread and causes the filter to swell. The fix for that was to buy the smaller filter.

[lakept]

Well, still can't figure out this problem. I have replaced spark plug wires, cap, rotor, and fuel filter. Same issue.

[bwana50]

I had similar problems last year with my '96 GT-40. I finally replaced the LP fuel pump and it's been problem-free since then. I still haven't figured out why it would work if restarted immediately, but not if it sat awhile, though.

[lakept]

Ok, so I just replaced the low pressure fuel pump this weekend and it seems to be better. I have about 8 successful warm starts in which the boat has sat for 20+ min after having a warm engine.

It will sometimes take a few tries but never more than three before it starts up.

[lakept]

Well, today was a bad day. I thought the new low pressure fuel pump fixed the problem since I had about 10 starts with a warm engine sitting for >= 20min but today I could not get the boat to restart after I ran it good and let it sit for 4 hours. Just don't understand this problem. I am considering replacing the high pressure fuel pump but don't feel that is going to do it either.

[gwach]

Was this problem ever solved?