4.3 Volvo Pent Fuel Pump or Relay Question

king3585

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Jul 16, 2013
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I have a 1997 Reniell with a 4.3 Volvo Penta engine. Having some issues starting it and determined there was no fuel making it to the carb. I'm wondering about the fuel pump. Should I hear it turn on when I turn the key on? Right now it doesn't make any noise. I have jumped it from the battery and it runs fine and then the boat will start. I just replaced the relay and that may have solved the problem but still wondering if there might be another issue with the pump not coming on. Any ideas? Thanks
 

erie_guy

Petty Officer 1st Class
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Jan 16, 2007
Messages
269
Re: 4.3 Volvo Pent Fuel Pump or Relay Question

I had a quiet pump two years ago and the solution was to have a new pump installed ($240). OUCH!

Sounds like you may have solved the problem already. Hope so. If it starts - problem solved. If "no-start" get out your multi-meter and trace the 12vdc from the ignition switch to the relay? and then on to the fuel pump. Some where along this path there may be an issue you need to address.

Happy hunting !

erie_guy
Port Clinton, OH
 

king3585

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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

Well, the problem continues. Took the boat out yesterday, however, before leaving the house put the mouse ears on it and started it without problem. Let it run for awhile to make sure it was good. Towed it out to the lake and put it in the water. Again started it before detaching it from trailer. Started with no problem and was idling while wife parked the car then suddenly it died and refused to start. Didn't smell flooded and upon opening up the carb I couldn't see any gas going in when the throttle was worked. Just acted like it was out of gas. Ended up having to haul it back onto trailer and take it home. Couple of notes: It has a brand new fuel tank, fuel and the anti siphon valve seemed good. The relay is new and has power.

At the house, I pulled the top fuel line and cranked the engine. Gas came out in a pumping action. Re-connected the fuel line and the boat started right up. Ran without problem. Took it to a nearby river and ran it for a couple of hours without incident, however, I was too afraid to shut it off...

Planning on changing the fuel pump with the assumption that it is hanging up and the trip to the lake jarred something. Also wondering if it could be losing prime during the road trip and it just ran the gas out of the carb before dying. Any other ideas? Probably not related but also ended up with excessive water in the bilge after just a couple of hours on the river (thinking bellows on that one).
 

dypcdiver

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Nov 1, 2005
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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

Sounds suspiciously like an air leak on the tank side.
If you suspect bellows, get the drive pulled soon before too much damage is caused.
 

king3585

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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

Thanks for the idea. I'll inspect the connections today and redo them when I swap the pump out. It did this two weeks ago after towing it to the lake but that is also when I discovered the pin hole in the fuel tank. Had to cut into the floor and swap the tank with a new one so I changed and tightened all the connections at that time. Then it did it again two days ago (very next outing after the repair). I did swap the fuel relay in between to try and solve the problem (before I saw Don's post about it only coming on when cranking/running).
 

dypcdiver

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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

A second thought is that you may not have a vent on the new fuel tank and could be pulling a vacuum. Easily checked by removing the filler cap whilst suffering from the problem and listening for an in rush of air.
 

king3585

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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

Checked the vent and it's open. But I did notice when I pulled the fuel pump the line below was empty. Isn't the anti-backflow device supposed to prevent gas from flowing back into the tank. I'm thinking the line should have had fuel in it. If so that valve could be the problem. Basically, losing prime - similar to the air leak tank side you mentioned.
 

dypcdiver

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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

Well worth a try, I think these things are fitted by the hull manufacturer so I have no idea what kind of valve it is or how to fix it. However you could try a gallon can of fuel with a hose to the pump to eliminate the tank supply.
Oh yes, and as it is a new tank make sure the strainer/filter on the tank pickup isn't clogged, can happen if the tank was not cleaned properly after manufacture.
 
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HalfFish5087

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May 30, 2012
Messages
278
Re: 4.3 Volvo Pent Fuel Pump or Relay Question

King,
Maybe you mentioned this earlier, but is this a carb engine (4.3 GL/GS)? I assume it is as a 97 and if so, you are describing the exact same thing that has happened to me, ie the boat would start and run fine then shut down after a few hours and then maybe it would start and maybe not. Eventually it got the point where I would have to prime the carb with about a cup of gas in order to create enough vacuum to start pulling the gas.

After checking all connections, making sure I was getting 12V while cranking and while running, and replacing the relay, I bought a new pump and that did it. She now starts after a few rotations every time.

I went with the federal mogul for a little bit of a savings and so far so good. Oh and make sure and get new orings for the top and bottom of the pump.
 

king3585

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Jul 16, 2013
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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

Thanks, Yes it is a carb engine 4.3 GL with a Holly carb. Replaced the pump a few days ago and for some reason it started over fueling. It was dumping gas through the carb . Then I rebuilt the carb thinking it was a stuck float but it still over fueled it. Went back to original pump and it started and seems to be working (might have been related to the carb). Will find out today!
 

king3585

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Jul 16, 2013
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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

Thanks again - the tank was clean at install. I vacuumed it out and checked the strainer/filter before putting new gas in it. I'm crossing my fingers that the carb rebuild fixed the problem and that it was the float getting stuck closed letting it run until the bowl was empty. Will test today.
 

king3585

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Re: 4.3 Volvo Pent Fuel Pump or Relay Question

Just an update for any with same problem. Carb overhaul and filter change seemed to fix the problem.
 
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