Fuel shut off

[Gregg]

Good morning all.

This is my first time using the forum and I have a fuel related question on my 2001. The engine is a 1998 TBI 5.0.

I had to replace the engine oil pan. On the initial start up after the engine was re installed, it would run for a few seconds then quit. It did this for the first 10 starts?, then ran fine. I had replaced the fuel filter while the engine was out, so I figured maybe that it took a while for the fuel to get to the throttle body. Ran the boat the next weekend for an hour or so with no issues. Tried to take it out the following weekend and it would idle for a few minutes, then stall. Tried giving it some throttle, but it would still not stay running. The electric fuel pump is howling. (Don’t remember it being that loud before the engine repair)so I ordered a replacement that I Haven’t received yet. I can see that the TBI injectors stop spraying just before it quits. Just wanted to know if there was some kind of fuel shut off function that I may be over looking? Obviously still going to replace the pump in the mean time.

PS. I took a fuel sample and found no signs of water

Thanks.
Greg

[donald]

The fuel tank fitting is a anti siphon valve, that may have failed when the sngine was replaced.
Don

[mmwjr]

Since the fuel pump is howling it's most likely bad. I would need to look at the wiring diagram but i believe there is also a relay for the fuel pump that may also be causing the loss of power to the pump.

[Gregg]

Thank you Don.

I’ve already checked it and it seems to be working normally

[Gregg]

It does have a fuel pump relay. I will replace that as well.
Thank you!

[mmwjr]

Originally Posted by Gregg

It does have a fuel pump relay. I will replace that as well.
Thank you!

You could use a voltmeter and see if the relay is removing power from the pump when it dies. if power remains then it's definitely the pump which probably has a thermal cut off switch internal.

[Gregg]

Hello all.

I replaced the fuel pump and nothing changed , same fuel
pump noise and same start/stall situation,. I don’t know why or how, but after checking everything that I could think of electrically and mechanically, I decided to replace the new fuel filter that I just installed while the engine was out. Low and behold, the problem is fixed. And I have no idea why.

[mmwjr]

The only thing I can think of the fuel pump was being starved for fuel. Maybe the filter had a defect or got clogged from some type of debris. You may want to check the tank to filter fuel line as it may be deteriorating inside from E10.

[Gregg]

I do think the fuel pump noise was aeration or starvation. Checked the pick up and tank. All seems fine. Thank you everyone for all of your input

[2004_3300_SCR]

This year the fuel fill and vent lines from the through hull fittings to the fuel tank (each about 6 feet long) failed internally on my 3300. Only symptom at first was that it was hard to fill with gas (kept burping back, I thought it was a clogged vent hose at first). They finally deteriorated to the point where I started getting a fuel smell, which is when I found the problem. I replaced those lines and the rubber feed/output lines (from the tank to the fuel filters) ... and the fuel filters as well. Anyway as Mike pointed out, deteriorating lines can be a source of fuel contamination.

[seaway]

Good afternoon
My fuel pump ( gen 2 cool fuel) is making a loud howl or whine also. Very hard to access, so what can I check before changing the pump. 1998 Maxum 2800. Mercruiser 7.4 mpi. Thanks