Help! 2001 supra launch 5.7 indmar

[DeanoFF]

I have a 01' Supra Launch and having troubles with the engine firing, starting, then cutting off after several seconds. In every instance i have taken the boat out for several hours with it running perfectly wakeboarding and turning it on and off it was fine until several hours later towards the end of the day it does this thing where it starts then cuts off after several seconds. It startred about 3 weeks ago and after the first time of being towed in i decided to change the fuel filter out thinking it was clogged and it would be quick and easy. I took it out for about an hour by myself and it ran perfectly. So the next weekend I took it out once again ran it all day turning it on and off throughout the day and it ran fine until several hours of being out there i went to start her up and she started up but cut off once again after several hours. So i took it to the shop they changed out my spark plugs and distributor cap thinking that might be the cause. I took it out and after 15 min of me taking it out same thing happened again. A tech came out to the water and hit the fuel purge valve nothing came out where fuel should squirt out. So I put in a new fuel pump thinking that had to be it took it out memorial day weekend and wakeboarded all morning from 8-11 turning it on and off several times and it ran perfectly. Went to lunch at the marina came back out and the same thing happened it starts then cuts off after several seconds. It seems like it might be electrical possibly a sensor that gets hot or something causing the fuel pump to stop working after several hours. The only thing I can think is to get the comp on it when the problem arises because I believe if it wont show up when its running good. If anyone has any input I would appreciate it.
Thanks

[CornRickey]

Interesting. I know one thing. Is be a little pissed with taking it to a shop and there answer is changing out the plugs and cap!

[DeanoFF]

yea your telling me

[GA2001Launch]

I have the exact same boat and it started doing the exact same thing to me this year. Nobody can explain it. Please let me know if you get it figured out...I will do the same.

[DeanoFF]

Please do its at the shop right now again

[haugy]

This sounds like Vapor Lock. Search in here, there have been threads on it.

[DeanoFF]

So I talked to a guy at Indmar and he told me to replace the anti-cyphon valve because this could be causing more air to get in the fuel. Other than that I had a couple mechanics tell me that putting in the premium fuel and some stabilizer could help the fuel stay cooler. Also, he said if that doesnt work to put a wet towel on the fuel lines and pour water on to the fuel pump after sitting for a little while. He said I could also run my blower while I sit and keep the dog house open if I sit for an extended period of time. Noone really had an answer to why it is doing it now. I did have one mechanic say you could replace your fuel lines and said they could possibly be clogged up from the ethanol in the fuel now. I also heard putting the wooden clothes pins all over the fuel lines and this will help absorb heat and possibly help stop the vapor lock. I took it out the other day ran it all day wakeboarding here and there sitting for 30 min at a time before turning the engine on and it ran amazing. Around 3 I turned it off and I sat for around an 1-1.5 hours before turning it back on. It turned on and ran shitty for about a minute before dying. I tried turning it on again and it turned over and ran for a couple secs before dying again. I opened my doghouse turned my blower on and poured some water on the fuel lines and fuel pump and waiting a sec then it started up fine and ran amazing the rest of the day. It just baffles me it all of a sudden is doing it and there doesnt seem to be a mechanical fix except for possibly replacing my fuel lines. Thanks for yalls help

[CornRickey]

If I was going to throw parts at it is throw a fuel pump.

[robdaniel1]

If I was going to throw parts at it is throw a fuel pump.


Try the MAP sensor. Had a similar problem with my 2001 and tried everything. Finally tried the MAP sensor and it worked