Repeated fuel pump failures

K

kmcculler

Recruit
Joined
Jan 12, 2012
Messages
4
Hi, I've got an old VP AQ131D that keeps burning through fuel pumps at a rate of about one a year. I'll buy a new one and slap it on, everything will work fine until next spring... this has happened several times. I do run the fuel out before setting it up for winter.

The pump will still function when I start it back up but I get this surging at WOT. I've tried hooking an external tank up and priming it during this time and it would run fine.... I let go of the bulb and it goes back to surging.

I've checked the plugs, wires, fuel line, fuel, and filters. Any ideas what could be buring up the fuel pump year after year?
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Repeated fuel pump failures

Stop emptying the fuel system during winterizing. It's not necessary at all, and may be your problem.
 
K

krazykatz911

Petty Officer 2nd Class
Joined
Aug 21, 2010
Messages
123
Re: Repeated fuel pump failures

When I worked for Federal Mogul / Carter Fuel Pumps, the two biggest issues we had with pumps burning out was:

1: Debris in the fuel tank (even though you empty it, could be dirt in tank)

2: Low voltage due to high resistance across the connectors, etc. Check voltage drop. The voltage drop measured should be 0.5V DC or less. (You must voltage drop test negative first and then positive)

A voltage drop of more then 0.5V DC will surely cook a pump and cause other driveability problems.
 
Don S

Don S

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62,321
Re: Repeated fuel pump failures

Guys, he has a 131, it's a mechanical fuel pump, not electric.
 
K

kmcculler

Recruit
Joined
Jan 12, 2012
Messages
4
Re: Repeated fuel pump failures

Just to update everyone. I think I found the problem. Someone on another forum suggested I try adjusting the float to allow for more fuel in the bowl.

I was skeptical as the fuel pump really seemed to be the issue to be but I thought I might as well give it a shot.... Worked like a charm. I took her out this weekend and I don't think she's ever run better.

Thanks for your help guys.
 
bruceb58

bruceb58

Supreme Mariner
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Mar 5, 2006
Messages
30,476
Re: Repeated fuel pump failures

Don S said:
Guys, he has a 131, it's a mechanical fuel pump, not electric.
Click to expand...
Jeez...that is what I get for not reading the whole thread. When he said burning up fuel pumps, never thought it could possibly be a mechanical pump.
 
Don S

Don S

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62,321
Re: Repeated fuel pump failures

I wonder what other information that other forum had that we didn't have. Since having the float level adjusted makes it better than ever, there must have been a problem at the end of last year as well.
 
K

kmcculler

Recruit
Joined
Jan 12, 2012
Messages
4
Re: Repeated fuel pump failures

No problems I could detect at the end of last year. I was highly skeptical the adjustment would work for me but I thought "hey its free to try it". Glad I did.

I went back and looked at the other post to see if I gave them any additional info.... all I could find was some slightly different wording and this "The surge will go up to about 4500rpms then down to just under 3k and back up. When I open it up it will run fine for about 10/15 seconds before the surging starts up."
 
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