Electric fuel pump on PSC 31

[AlLorman]

Wiley:

Alas, mine matches the diagram in the manual.

I want to emphasize that there was nothing wrong with my fuel system, except for the broken electric pump, before I replaced the pump. The engine ran fine. All we did was remove the broken pump and replace it with an identical unit. That leads me to believe that, as others have said, it is a priming issue. Since my boat is laid up for the winter, I will probably postpone resolving this issue until spring, when I change the engine mounted fuel filter.

Al

[wsmurdoch]

The instruction sheet that came with my Walbro fuel pump says "A fuel filter must be installed between fuel tank and pump..." In the drawing on the back of the sheet, a filter is shown between the tank and pump; it is labeled "filter is imperative for operation". I assume the filter protects the valves and other pump internals from trash in the fuel.

My Yanmar Service Manual says for the engines 1GM10(C), 2GM20(F)(C), 3GM(30)(F)(C), and 3HM(F)(C) that the maximum suction head for the 105582-52010 and 129301-52020 mechanical pumps is 0.8m. That is 31.5 inches. My engine's pump is about that far above the bottom of the tank. If I add in the friction head for a dirty Racor filter (10 in Hg where the red line is on the Racor vacuum gauge) and the friction losses in the hoses and fittings, I'll greatly exceed 31.5 inches of diesel fuel.

Although the drawing in my Pacific Seacraft Owner's Manual shows the electric fuel pump before the Racor fuel filter, the actual installation is the other way around.

Bill Murdoch
1988 PSC 34
Irish Eyes

[okapi3]

I have been following this thread with interest because when I purchased my 31 (#9) there was no electric fuel pump installed, and the engine runs fine. But in one of the lockers I found a brand new marine electric fuel pump , still in the box. Going to the engine compartment I find a block with mounting bolts which fit the fuel pump and wires capped off terminating there (BTW it is AFTER the Racor).

My question is, given that the pump is free, in the experience of those with electric fuel pumps, would you recommend that I go ahead and finish the installation that the PO obviously either aborted or ran out of time to do?

I would use it only for bleeding purposes, with a switch right by the pump. I have not found the little finger pump to be very effective so my inclination is to install it.

Any input would be appreciated. Thanks in advance.

Paul

[wmjr]

Paul,

My 31 is set up just like yours. When the electric fuel pump broke bleeding was a pain. When I replaced it bleeding become fun again. Give it a shot.

John
Watermark
PSC 31 #28

[andantesail]

Mine's a Walbro and is self-priming. The ignition key needs to be turned to the right, but without starting the engine. Then the Walbro runs and avoids the need to bleed the engine.

[teejayevans]

Does anybody have the fuel pump connected to a oil pressure switch?? Mine is (factory installed). Also, I guess the current draw (~2 amps) is not too much to be supplied through the engine panel? I was thinking of adding a relay, those engine panel wires look awfully small.
Tom

[okapi3]

Originally Posted by wmjr

Paul,

My 31 is set up just like yours. When the electric fuel pump broke bleeding was a pain. When I replaced it bleeding become fun again. Give it a shot.

John
Watermark
PSC 31 #28

Thanks John. I will. I can't wait to experience the "fun" of bleeding my Yanmar!

Paul

[andantesail]

In Andante the electric pump is installed before the Racor.

[wiley586]

I'd never disagree with those who say their pump is before their Racor. If it is, it is. I merely note that my 31's manual says the same thing and regular visual inspections for leaks and such never caused me to doubt it. I'd have bet several boatbucks on it.

But when I actually had to work on my fuel system, I found something different. My fuel line runs from the tank, behind the pump, to and thru the Racor, back behind the Racor and the pump, thru the pump, behind the Racor, and finally to the engine. Yes, there are 2 180 degree turns in the fuel lines. This sounds crazy, but it is so. Given the relative sizes of the Walbro and the Racor and the layout of the area, it even makes sense.

Again, I'm not telling anyone this is how their boat is set up. But I doubt that many people would have deduced the actual setup on my boat without actually removing and tracing fuel lines. Your mileage may - and probably does - vary.

I'm just sayin'.

Wiley