1986 Supra Sunsport Dies, then runs good

[freddyk]

Hello All,

1986 Supra Sunsport 700 hours 351 Ford.

Boat runs like new but occasionally will just die. won't start back up immediately but if you wait about 5 min, it will run perfect again.

problem started last year, I put a new fuel pump and cleaned the fuel filter. I also put some heat in the tank but ran almost all fuel out last season.

I replaced the coil, but with an older used coil I had in the garage. I am thinking about maybe trying a new coil but I am not sure.

Any ideas much appreciated I love this boat but my wife is starting to hate her

Fred

[michael hunter]

Does it have points or electronic ignition?

[OUI]

A bad coil will cause that problem. As soon as it heats up it will die. Another situation that causes that problem is a clogged breather tube to the gas tank. Unscrew the filler cap and drive around to see if it still dies. If it doesn't then it's the breather tube.

[freddyk]

I agree with getting hot and the coil being a culprit. What's so weird about that is Sunday we took it out, romped all over the lake at WOT, skied at midrange, cruised at idle for a total of 2 hours. Not a problem. Then yesterday, I took it oout and within 7 minutes of starting it the boat promptly died and wouldn't restart for about 5 min. I don't think it could have even been 150 degrees at that point because we were just starting.

I think I will try another new coil first to at least eliminate that.

Thank you for the breather tube idea. I will take a look there if it dies after replacing the coil with a new one.

Fred

[DAFF]

Try to get a sample of the fuel in the tank. Somtimes a little water will get in the fuel and the engine will suck some up and die out. After sitting for a while the water and fuel will separate again and it will run perfect for a while untill the boat slurps some more water.

Remove the filter and dump the fuel into a glass gar, this will let you know the condition of the fuel in the tank.

[bdumas35]

A restricted fuel tank vent could be a possibility. Run it with the fuel cap loose to check.

[Rusty]

Check your temp gauge. You might have a bad impeller.

[freddyk]

I got it figured out. I replaced the coil but as expected no improvement. So then I focused in on the fuel system. I removed the back seat in order to inspect the fuel tank vent. However, in doing so, it exposed more of the primary fuel line running from the tank to the engine. A quick inspection proved that the line was rotten!!! I assume from sitting in the water over many years. I'm pretty sure that occassionally, the engine was taking a big gulp of water, which was killing the motor. Upon waiting for a little bit, the water would settle down into the motor, then it would run good again.

$20 fuel line and an hour later, my boat runs like new again! YEAH!!!

Thanks for the input everybody!