Fuel Pump??

[SupraTom]

After about 200 hours of boating this year I have run into my first problem -No fuel to the carb!

It worked fine for the majority of the day and then all of a sudden while i was being pulled on a slslom ski the boat died as if though it had run out of gas. There I sit watching the boat drift away... Good thing I'm a strong swimmer. Anyways, like I said there is no fuel running to the carb.

Is the fuel pump the only thing that could be wrong if given the lines don't leak?

[H2Oman]

What type of boat and engine do you have?

[OUI]

It could be your fuel filter(s) or a clogged gas tank vent. You can check that by removing the filler cap -- that will let in air and if it runs after that then your vent is clogged.

Replace the inline filter, and clean the filter at the carb, if it still doesn't work it's probably the fuel pump, you can check that with a pressure gauge.

[IndyMatt]

Typically speaking, if the boat stopped abruptly, and you didnt notice any performance issues prior to this than your probably right on with the pump. If a filter was on its way out as well as a vent issue, your symptoms would of begun with loss of performance developing into cold soak. Im assuming you took the flame arrestor off and looked into the carb while someone cranked over the motor and didnt see any fuel being jetted into the throttle body. Start with the wiring, make sure all connections are still intact to the fuel pump. If you cant see obvious disconnect, pull the pump and have a local shop test it for you. Its always a good idea to service filters as well. This may sound dumb... but fuel senders and float guages go bad all the time too... just confirm that you do actually have fuel in the tank, also check the pick up line in the tank & make sure it has not become disconnected from the sender. Some have a rubber hose, others have a rigid stem with a filter on the end. Good luck.

[SupraTom]

I have a 85 Supra TS6M Comp with the 351 (for those who were wondering). The pump is mechanical, not electric.

After checking the vent, lines, and filers I found nothing wrong.

I pulled the lines off of the pump and found that there is no suction but there is pressure on the outlet side.

Correct me if I am wrong, but I think that pretty much verifies that the pump is shot... Thats a shame considering its just over a year old.

[DKJBama92Mariah]

There should be a sight tube running from the pump to the carb. This tube is a clear plastic tube that is separate from the fuel hose. The purpose of this tube is to let you know if the pump has a ruptured diaphragm. If there is fuel in this tube, a diaphragm has ruptured and the pump is shot.

If not, it still could be shot. I think you're on the right trail. Try connecting the fuel pump intake to a spare length of hose and put the other end in in a portable gas can and see if it pumps then. This will tell you for sure if you have a problem somewhere before the pump.

DKJ

[SupraTom]

:x :x :x
I replaced the bad fuel pump yesterday. After installing the new one it ran great in the driveway for about 5 minutes. I decided to venture to the lake to do some skiing. After launching the boat ran great for about 5 min when all of a sudden it died again.

There was plenty of fuel in all of the lines. After disconnecting the outlet hose from the fuel pump and sticking the inlet hose into a can of fuel I found out that pump #2 is shot. It too is not pumping fuel. It worked on the driveway and for a short period of time in the water, but then It died on me.

Has anyone else had these fuel pump problems? I will test out pump #3 on Tuesday. Hopefully the third time is a charm.

[SupraTom]

Pump #3 works like a charm. Looks like my replacement pump from the auto store was made on a Monday or Friday. Thankfully it comes with a 1yr warranty.

FYI- There was no fuel in the sight tube. This goes to show that you can had a bad pump without fuel in the tube.
Also, if you own a Supra from the mid 80's with the 351 you can pick up the pump at most auto part stores, its the same one you get from skidim. Part # M 60389 (mechanical pump). It's a little more expensive ($100) but the convenience of replacement and exclusion of shipping charges was well worth it.

Tom

[DKJBama92Mariah]

That fuel pump you bought. Is it a marine specific version, or just a parts store pump for a 351?

Marine pumps are different than auto pumps. Auto pumps have a single diaphragm, and when it ruptures, it just dumps fuel underneath the car.

Dumping fuel into the bilge of a boat is a big NO NO. The marine pump has a secondary diaphragm to catch the fuel and send it up the sight tube to the carb as discussed above.

Auto parts can be very dangerous on a boat. Alternators, distributors, starters, fuel pumps, and flame arrestors must be marine specific parts.

If you did buy a marine pump, the please excuse the rant. SAFETY, SAFETY, SAFETY. Riding in a fiberglass time bomb is not my idea of a good time.

[SupraTom]

It was a marine fuel pump

The new one works like a charm. I guess I just got a bad one.

[milner351]

glad you got it fixed.

another note on fuel system components.

while restoring my '86 comp I decided to clean up the fram fuel filter / water separator canister....

the corrosion inside the canister was so severe that it rotted all the way through the canister itself - through nearly 1/8" of aluminum.


inspect your filter housing carefully the next time you change your fuel filter - if there is corrosion present - replace your filter set up with a newer spin on style filter - it will make changes in the future easier too.

$100 for a marine fuel pump does not sound too bad.

I've found dbstarteralternator.com to be unbeatable for marine electrical components, my new gear reduction style starter was not only 10lb lighter than the old style starter - but only cost me $60 to the door, and it's marine spec.