bad fuel pump?

[StyxPix]

This is my first post so if i miss something please forgive me.
I have a 1987 Four Winns Vista Cruiser with a 5.7 OMC cobra engine. For sometime I have been having issues ( well over a year) with the boat bogging down as I open the throttle up. The plugs n wires etc were replaced, new in line filter, carb was supposed rebuilt by a mechanic but the issue continued. I went to the boat yesterday, started it up and while it was running it died out. Looking at my fuel gauge it read just above E. I put in stabilizer with 10 gallons of fuel, worked the throttle and started it. Boat turned over, ran, died out, same thing another 4 or 5 times and then would not turn over at all. Turn the ignition on and it just tries to start. Am I logical to think this is the fuel pump. Am I correct this is an external fuel pump? Any way for a novice to test and verify it is the fuel pump?
Thanks in advance for any advice and assistance.

 

[StyxPix]

Re: bad fuel pump?

26 views and no advice? LOL Is my problem that bad?
Some additional info, i went to the boat at the lake yesterday and removed the fuel/water separator filter thinking maybe it was pumped "dry" from trying to start the boat but there was fuel in the filter so I surmised it did not need priming. I guess the next step is to bite the bullet and replace the fuel pump.

 

[SeanMcl]

Re: bad fuel pump?

I guess the next step is to bite the bullet and replace the fuel pump.

No, the next step is to TEST the fuel pump, as well as the other parts that make up the fuel system. Build yourself a pressure/vacuum rig like the one in the link and you will know if your fuel pump is bad or not. It will cost you less than $30.

http://forums.iboats.com/showthread.php?t=283269

Also, check the other sticky posts in the "Adults Only" section at the top of the OMC forum. Tons of great info there. Don't let the name fool you, it's all tech stuff.

 

[Joshua Nichols]

Re: bad fuel pump?

I would test the fuel pump before I replaced it..

Sorry we all missed your post.. It was a holiday weekend.. Most of us go boating on the weekends during the season..

Pour that fuel in the water separator in a glass jar.. Just to see if you have water

 

[StyxPix]

Re: bad fuel pump?

Thanks, I will do both.

 

[heiliges]

Re: bad fuel pump?

I am working through a similar problem and am attacking the fuel system today. If I come up with something, I'll post it so you know what I did to resolve the issue, if it gets resolved of course.

 

[StyxPix]

Re: bad fuel pump?

I would greatly appreciate if you would. Any info would help.

 

[StyxPix]

Re: bad fuel pump?

Will I be able to perform this test if the boat does not start? Will turning the key and just trying to crank the motor show me if I am having a fuel pump issue? Sorry for the ignorance but I would not even put myself in class of being a shadetree mechanic because it would offend the other shadetree mechanics lol

 

[drem312]

Re: bad fuel pump?

I had a similar problem on a 30ft sportcraft and found it to be the fuel pickup tube inside the aluminum gas tank I found the problem by disconnecting the fuel line after the fuel water seperator and running a sep gas tank and gas line direct to the fuel pump with clean fresh high test fuel and then traced it backwards the boat ran great on the sep tank sure enough the tube inside the tank was clogged and the more throttle i gave the less fuel would get to the carb the antisipon valve the litte ball inside the tube had crap around it too

 

[SeanMcl]

Re: bad fuel pump?

Will I be able to perform this test if the boat does not start?

Yes. When you check the fuel pressure side (the gauge is between the pump and the carb) it should come up to 5 lbs within a 2 or 3 second crank of the starter. For the vacuum side, when the gauge is between the pump and the tank, you shouldn't see more than 5 in/hg of vacuum. Mine was 20 in/hg when I had a plugged fuel pickup, and 2 in/hg after I fixed it. I had similar symptoms to you.