Fuel Pump Question 1995 Prostar 190

[Blackhawk36]

I am working on resurrecting this boat. So far I have checked out the engine. Installed new strut bushings and put in a new ZF transmission. It has a 5.7L GM Indmar engine.

Everything is ready to start up but there is no fuel coming out of the fuel pump. This boat has an external electric fuel pump mounted on the bell housing. When the key is turned on you can hear the pump prime for 3 seconds like it is supposed to. With my thumb over the outlet I cannot feel any pressure or suction. The fuel tank is full.

The engine will start on starting fluid.

Has anyone ever had a situation where the fuel pump runs but does not pump fuel? Does anyone know whether it matters which way the wires are connected on the pump. They have been spliced before. There is no (+) or (-) on the pump.

[Olaff]

It's a DC motor so it could be wired backwards. Or, depending on the age in hours, the gear that drives the pump mechanism off of the motor shaft could be disengaged (i.e. "tore up") so the motor spins but the pump doesn't.
Could it be an obstruction in the filter screen or hose from the tank to the pump?

[Blackhawk36]

Thanks Olaff. Checking for obstructions this evening.

[Jerseydave]

Make sure the fuel shut-off valve is open at the top of gas tank.

Like Olaff said, check screen at base of pump for debris. At inlet line.

[TallSkinnyGuy]

That pump is not strong enough to pull fuel all the way from the tank through an empty fuel line. I had to siphon fuel through the line and then connect it to the fuel pump to get it to work. I did this by connecting a clear hose to the end of the fuel line (obviously after disconnecting it from the fuel pump) and siphoned fuel through the line until I could see fuel coming into the clear line (then let it go back just a little). I then turned off the fuel shut-off valve on top of the gas tank to keep the fuel in the line while I disconnected my clear hose and reconnected the fuel line to the pump.

If your pump is actually working properly you will need to do this or some variation of it to make sure you have fuel in the line between your tank and the pump.

[mikeg205]

you need to bring fuel to the pump.. you can get a cheap $10 pump from hardware story.. I never recommend using the mouth method..

the 95 TBI pump and the MPI both need to be manually primed...

do it soon so you don't burn up the pump... gasoline cools it.

[Blackhawk36]

The polarity was backwards. I switched the connector around and it pulled fuel out of the tank and started after about 3 seconds of cranking. Ran silky smooth for the 30 minutes. Very happy. Sea trials soon.