[Capt'n Chris]

We got stranded for the 2nd time in 2 seasons last night.
I'm wondering what makes a fuel pump fail besides the obvious mechanical issues with the pump itself. As I understand fuel pumps don't create a lot of pressure, so do I have something in place that could be restricting fuel flow? Is it a over or under voltage issue?

5.7l Mercruiser engine w/ Mercruiser fuel/water separator filter.

Any insight would be appreciated. I think I'll buy 2 fuel pumps and keep a spare on board.

 

[Garry]

Is the pump mech or elec?

Lot's of reasons it could go bad. You could have gotten a junk pump - even though "new", a lot of the Chinese junk is just that......

You may have a restriction on the suction side making the pump work over time thereby shortening it's like....

If elec, low voltage can cause premature failure- check all connections and grounds, make sure they are perfect, check voltage supply.

 

[Dante421]

Probably junk chinese electronics at their best. I've had several junk electronic purchases recently. 2 hard drives for my computers and one washdown pump for the boat. CHINESE JUNK

 

[Capt'n Chris]

Thanks for the input guys. It is an electrical pump, and I'd love to blame the Chinese for this but there is a Made in the USA stamp on the pump.

How much volts should this pump have? I measured 10 DC Volts with a meter I borrowed from work.

 

[kc8nlf]

You should have at least 13.5 VDC while the motor is running. Low voltage will cause high current which will heat up the pump motor and possibly blow.

 

[Garry]

QUOTE(garry454 @ Jul 30 2009, 02:37 PM) <{POST_SNAPBACK}>If elec, low voltage can cause premature failure- check all connections and grounds, make sure they are perfect, check voltage supply.

QUOTE(Capt'n Chris @ Aug 3 2009, 11:36 AM) <{POST_SNAPBACK}>How much volts should this pump have? I measured 10 DC Volts with a meter I borrowed from work.

BINGO!!! Solve that, and you will be good to go!! Start with all the connections from the pump back. Don't forget to clean the battery connections, and check you voltage at the battery(ies) first. Could be a bad battery, cable, ground, you name it, but at least you know why now.

 

[sleeper]

I have found that when I have an electrical issue, it is almost always a ground problem.

Good luck.