Bad fuel pump??

[caddyshack9]

Howdy. My girlfriend has a 1998 Supra Launch. It has what I assume an Indmar V-8 which looks to me to be basically a chevy motor. I know nothing about boats but a little about motors. We got stranded yesterday. Boat would start and run for 5 seconds and then quit. I unhooked the fuel line from the water/fuel separator and it is pumping and then quits after the few seconds. I would guess bad electric fuel pump. She says it has been doing that for awhile and if you keep it running it does ok. After you shut it off and it sits awhile then it won't start and stay running until like the next day. She has a friend that thinks it's a carb float problem but I think it could be EFI and if it isn't pumping gas then the float wouldn't matter!!

Any help would be appreciated. Thanks so much!

[docdrs]

well is it efi or carb?.....efi will have a throttle body with injectors on the top of it.....I don't think they were mpi back in 98...ooops i 'm wrong maybe they were just looked at the 99 and it says mpi.....so no tbi.....you will see fuel rails going to the injectors

[caddyshack9]

Yes, it has the fuel rails on it. Again, when I pulled the fuel line off the seperator it just pumped for a short time and quit. Unless the power going to the pump is cutting off I would think fuel pump. Do they have a fuel pump relay??

[Engine Nut]

The pump only comes on for a 2-3 second prime when you turn the key to the on. It should also come back on as long as the engine is cranking. Put a fuel pressure gauge on the fuel rail and crank the engine. The pressure should be 36-45 PSI. The pump is activated by a relay. I tried to attach a diagram but it was too large for the system. If you need one PM with an e-mail address and I will send it to you.


Yes, it has the fuel rails on it. Again, when I pulled the fuel line off the seperator it just pumped for a short time and quit. Unless the power going to the pump is cutting off I would think fuel pump. Do they have a fuel pump relay??