dry carborator

I'm having a problem with my Baja. It has a 454 (7.4L), normally runs perfect. It ran fine, then out of nowhere would not start. Checked and it is getting plenty of fire. Checked the carb and it's dry. Primed the carb with a little gas and she fired right up. Ran fine, I ran it for 1/2 hour, then it started up enough for us to get 100 yards from the dock then it died. Same problem. Primed the carb and it ran just fine.
I plan to change the water seporator and the fuel filter, since those need replaced anyway and are the cheapest fix.
Have any of you heard of a fuel pump going out that would act that erratically? Any other ideas what might be wrong?

Doc said:

I'm having a problem with my Baja. It has a 454 (7.4L), normally runs perfect. It ran fine, then out of nowhere would not start. Checked and it is getting plenty of fire. Checked the carb and it's dry. Primed the carb with a little gas and she fired right up. Ran fine, I ran it for 1/2 hour, then it started up enough for us to get 100 yards from the dock then it died. Same problem. Primed the carb and it ran just fine.
I plan to change the water seporator and the fuel filter, since those need replaced anyway and are the cheapest fix.
Have any of you heard of a fuel pump going out that would act that erratically? Any other ideas what might be wrong?

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Does the carb have a fuel filter built in? Change that too. Is it a mechanical fuel pump or electric? I've had trouble with the pivot wearing out on a mechanical and cutting the amount of fuel pumped.

Jim

A hornet's nest or some other bug's nest plugging your fuel tank vent(s).

Mechanical fuel pump. The marine mechanic helping me said he has never seen a fuel pump on a boat go bad. Surprised me.
But, from the little I know, a fuel pump either works or it don't. Priming the carb would not make a broken fuel pump work ...and it wouldn't work perfect once it did start working.

The only fuel filter I know if is the one built in the carb.

Hornets nest blocking the vent??? Sounds like you might have had that issue at one time or another Fred. It's not a vent issue. We did think to check that when i was gassing up.

One other possibility is that the check ball valve in the gas tank might be plugging the line, and the prime blasts it out of place. If the filters don't fix it we are checking that next, unless we get a better idea from yous guys.

Check for soft hoses on the inlet side of the fuel pump, all the way back to the tank. They could be collapsing under suction. Sure sounds like a venting problem of some sort. It could take a while for the suction to build up so high that you starve the carb. By the time you prime the carb, air is back in the tank.

But, if all seems ok, and the filters check out, do you have a fuel pressure gage on the boat? If pressure did not drop before the carb ran out of fuel, then maybe the float is sticking in the up position for some odd reason?

Also, can you get to the tank side of the vent connection? If so, take it off and blow through it. Should be free flowing.

Sounds like the fuel pump. Had one go on my dodge before. It would die, then I could get it fired up, go for a bit, then die again..... Ended up being a weak fuel pump.

waybomb said:

Check for soft hoses on the inlet side of the fuel pump, all the way back to the tank. They could be collapsing under suction. Sure sounds like a venting problem of some sort. It could take a while for the suction to build up so high that you starve the carb. By the time you prime the carb, air is back in the tank.

But, if all seems ok, and the filters check out, do you have a fuel pressure gage on the boat? If pressure did not drop before the carb ran out of fuel, then maybe the float is sticking in the up position for some odd reason?

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Ahh, good info Fred. I know that when I fuel up gas will come out the vent and it is not plugged at that point. A weak hose very well might be the answer, I have not changed hoses ever, and the boat is 18 years old.

Both times though it failed, it had been off for a short period, and it fired right up ....then after idling away from the dock or other boat before taking off it would die. This last time I was ready for it and thought pumping the throttle would keep her going. Wrong. It died just the same.

groomerguy said:

Sounds like the fuel pump. Had one go on my dodge before. It would die, then I could get it fired up, go for a bit, then die again..... Ended up being a weak fuel pump.

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Interesting. Thanks for that info. The fuel pump is in a horrible location to get to on this boat ....so I was hoping that was not it ...and I never thought it would work intermittently as mine has. Another possibility to check out.

Thanks guys!!!!!

Doc, I had a similar problem with my tractor: it would be running fine, then start sputtering, and eventually die. It would limp along if I kept fooling with the choke lever. Once it died, if I let it sit for 5 minutes, it would start and run fine for a while.

Finally figured out there was trash in the fuel tank. Had the tank cleaned and re-surfaced, and all is well.

Good luck. I know it is a PIA when a boat starts giving problems, and it is very embarrasing to be sitting at the ramp and the boat will not start, or you have just pulled away from the ramp and the boat dies.

Bob

Thanks Bob. Good info. I also considered water in the tank, but have not had the 'popping' that you normally get when water goes thru the carb. On this boat the gas tank is hard to get to. I sure hope that is NOT the issue. But I'll keep it in mind if nothing else fixes the problem.

The directions for the fuel water filter on my diesal tank basically states to have a new spare filter on hand because once full w/ water.. it prevents the flow of fuel.

kensfarm said:

The directions for the fuel water filter on my diesal tank basically states to have a new spare filter on hand because once full w/ water.. it prevents the flow of fuel.

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Yeah, I heard that. It's a good thing overall. But we changed my water seperator and the little filter at the carb. The water seporator was full of fuel, no water in sight (poured it in a glass jar to check). The fuel filter was a little dirty, but not bad. We were able to get 3 turns on the clamp holding the fuel supply line on. The hose seems okay, and it had not caved in anywhere, but it was not experiencing the problem at that time. So ... I really don't even have a warm fuzzy that we fixed anything. I hope to try it tomorrow, weather permitting.