Carter Universal Fuel Pump Problem?

[navigator336]

My boat has 2000 350 carburated Vortecs. The fuel pumps are Carter Universal 5.5PSI. The port engine started dying after running at idle for a few minutes. I found the 50 AMP main breaker had tripped. I reset it and it was up and running again. A few days later it did it again. I reset the breaker and this time it ran for about 2 minutes then sputtered and died. This time the main breaker was not tripped. The engine would restart and run for less than a minute and die. I tried this repeatedly with similar results. When I pumped the throttle as it was sputtering, it would try to continue running for a couple of seconds. I found the oil pressure/ fuel pump cutout switch very hot (the one near the distributor). I jumpered it and the engine ran fine. I replaced the switch and the engine worked well for a couple of months. This weekend it happened again. Engine was at idle in the slip. It ran for 5 minutes or more and then died. The main breaker was tripped. I check the cutout switch and it was very hot. Since the switch was so hot and new, I suspect that the fuel pump may be drawing too much current which initially trips the main. After a reset, the switch contacts are possibly burning and end up in an "open" state. That may explain why the main breaker doesn't trip after the first couple of times.

Is this a reasonable assumption or should I be looking elsewhere for the problem? I hate to replace the fuel pump if there maybe something else in the electric fuel pump circuit which could be causing the high current draw. Any thoughts would be appreciated. Thanks.

 

[Haut Medoc]

Re: Carter Universal Fuel Pump Problem?

Sounds like you have something grounding where it shouldn't.......​

 

[Don S]

Re: Carter Universal Fuel Pump Problem?

What type terminals are on the ends of the wires going to the OP Switch?
If they are the spade pushon type, are they clean and tight on the switch? Was your old switch all rusty by any chance?
You could get an amp meter and check the amperage of the pump, but I can't imagine the wiring handling 50 amps till it posps the breaker

 

[navigator336]

Re: Carter Universal Fuel Pump Problem?

I will check the wiring before buying the pump. If it is grounding somewhere, it must be a high resistance grounding or as Don mentioned the wires should fry. I think the wires are 16 gauge. The connectors are female spades and are pretty clean. The old switch contacts were a bit blackened from getting so hot. I broke the old switch open and could smell that "baked" bakelite smell. I'm guessing the fuel pump shouldn't draw more than 3 to 5 amps. There is one wire coming to the op switch and two (attached together) leaving. The incoming is blue (I think - being color blind) and the exiting ones are the same blue and orange I think. Where does the orange wire go to? Maybe that is the culprit.

Thanks for your ideas.

 

[Don S]

Re: Carter Universal Fuel Pump Problem?

You should really have 2 wires suppling power to the pump and 1 going to the pump.
What type pump do you have, there are lots of Carter pumps, is it like this one

What type engine is this on, OMC, Volvo, Mercruiser? (I know it's a 350 Chevy)

Perhaps you could take some pics and post them. That way we could see what your orange and blue really is

 

[navigator336]

Re: Carter Universal Fuel Pump Problem?

That's the pump Don. The engines are Indmar's. The wires are in a harness and I haven't buzzed them out, so I was assuming the single blue was the feed rather than the two bundled together. I believe Indmar used to use a op switch with three contacts on it, but switched to the two version for "reliability". So if there are two feeds, is the "orange" one a bypass for start-up while the oil pressure is coming up? If this is the case, where does the start-up voltage come from?

Thanks again.

 

[Bondo]

Re: Carter Universal Fuel Pump Problem?

If this is the case, where does the start-up voltage come from?

I believe the power should come from the Other Little Terminal on the Starter's Solenoid.......
Not the Exciter Wire,.... The Other 1............

 

[Destin]

Re: Carter Universal Fuel Pump Problem?

I have that same Carter fuel pump on my replacement Vortec engine with a QJet carb. After several hundred hours it started doing the same thing, but not tripping breakers. Engine ran fine, but would intermittently die while idling around and restart immediately back up. I found my fuel pressure was under 3 PSI, although it had plenty of flow. I bought a new pump and it holds 4 to 4.5 PSI. No more problems. I think an electric pump loses over 1 PSI lifting the gas out of the tank and thru the anti-siphon valve. This may or may not be related to your problem.

 

[navigator336]

Re: Carter Universal Fuel Pump Problem?

Thanks Don, Bondo and Destin.

I hate replacing something that doesn't need replacing, but it certainly wouldn't be the first time. So I think I'll put a new fuel pump in and hope that is it.