Troubleshooting fuel pump on Volvo 4.3GL

[aludski]

I?m having a fuel problem with a Volvo 4.3GL in a 1999 Larson 176. A couple of times in the past I?ve had some difficulty starting it in my driveway, but it?s never given me a problem on the water during the four years I?ve had it. One of the times I couldn?t start it there was no fuel going into the carb when I pumped the throttle, I pulled the fuel line at the carb and found no fuel when I cranked the motor but then it started to flow in a few cranks. I reconnected the line and it started right up.

When I went to winterize it last year I couldn?t get it started, hoped it was just the cold and figured I deal with it in the spring. When I finally got it out a couple of weeks ago, it started right up and ran perfectly. Yesterday I had her out and cruised around a bit, running her for a few minutes to an hour at a time, stopping and starting at least half a dozen times with no problems. At the end of the day after about a half hour stop, I started her to head back to the dock, gave her some throttle to get on to plane and just has it started to get up, the motor stumbled and died. If I pumped the throttle a few times I could get it to begin to start, but it would die immediately. When I got her home I pulled the fuel line and couldn?t get any fuel to flow, even after a lot of cranking. Pulled the fuel filter, found the fuel was about an inch from the top, poured it into a cup and it looked fine with no sign of water or dirt. I filled the filter to the top and poured gas into the fuel line to prime it. After that I was able to get the fuel to start flowing a few seconds after I began cranking it. Put the fuel line back on and it ran perfect.

In reading other posts, I?ve seen similar problems attributed to a bad fuel pump, a problem with the anti-siphon valve, or vapor lock. Any one have some suggestions on how to determine the root cause? If it?s the fuel pump, any thoughts on the quality of aftermarket pump compared to the much more expensive Volvo pumps?

Thanks!

 

[Brewerjk]

Re: Troubleshooting fuel pump on Volvo 4.3GL

I hope you find the answer to this because I am fighting the same problem. I did replace the fuel pump but no change. I can do a couple of things when this happens to get it going again. One is to idle for a few minutes after I have stopped for awhile. This seems to break the vapor lock before running the carb bowl out of gas and get the fuel going. If I do get on the throttle after setting awhile and shut the engine down, I can disconnect the fuel line and put it back and it cranks back. Or I can keep priming the carb with fuel to get it going again.

Good luck!

 

[spktho]

Re: Troubleshooting fuel pump on Volvo 4.3GL

Make sure to check and make sure there is voltage to the fuel pump while cranking and also after the engine is running.

Power should be going to the fuel pump from the starter solenoid during cranking. Then after the engine starts, power comes from the alternator through a diode and relay(at least on my Volvo 4.3).

I have been having a similar issue this summer and replaced the relay, the connection to the alternator and cleaned all other connections as there was some corrosion. I found that there was no power to the pump after the engine started which pointed to an electrical issue and not a pump issue.