fuel lift pump died

[newboatowner]

Hope that all of you are in the water, sailing and enjoying the summer. I, unfortunately have not been able to get out of the dock due to a myriad of problems, domino effect.

After waiting for a repair of the furling that was damaged when the boat was put in the water I discovered that my lift pump was not functioning. Apparently the power wire was torn out of the unit. I replaced it with a diesel lift pump (12 volt) that I purchased from an automotive supply house. The original pump was available only on the net and I wanted to get it fixed "now". I installed it and it appears to be working well.
The question is whether or not I can rely on this $60 pump or should I order an original replacement for double the price?

 

[jrowan]

If it works, then why replace it? If it is already installed, & operates properly then there's no harm in running it for as long as possible. Prices are not always commensurate with quality, & a small fuel pump really shouldn't cost that much. I joke that you can stamp "marine" on almost anything & charge ten times too much for it, such as "marine" toilet paper. If you are concerned about durability, then by all means order a second back up pump, as its always prudent to keep spares. Sounds like you can buy a second pump & still come out for the same price as the original type. Just be glad it was not the fuel injection pump, going bad, as they can cost a grand or more, & are specific to the diesel engine & cannot be replaced with after market knock offs.

 

[centerline]

personally, if my lift pump ever goes bad, i will replace it with an electric model.... and carry a spare.
they work for many thousands of miles on cars, and whether its driven by the cam in the engine or driven by its own little motor, it is prone to failure sooner or later either way..
I like the fact that they can be wired with an easily accessable push button and used to prime the filters after a filter service.

when hooking up an electric pump in the system to replace a failed mechanical pump, the lift pump on the engine should be bypassed because even though they have a double diaphragm and a weep hole in them to prevent problems, I have seen the diaphragms fail and dump fuel into the crankcase.
using an electric pump would still push fuel into the crankcase thru an aged and damaged diaphragm in the mechanical pump and cause the same engine damage.... and if the mechanical pump is still installed, it will still be cranking and trying to pump and wearing the diaphragms, so if you arent using the mechanical pump, bypass it.....

 

[Snotter]

I bought one of those electric diesel pumps 5 or 6 years back from a local autoparts store. I installed it before the primary filter and used it for the purpose of bleeding the fuel system when working on the engine.

A few years back, after the first day of a one-week vacation, my mechanical lift pump gave out. I thought I was going to have to call boat US for a tow back to home port. Fortunately, I got the idea of using the electric fuel pump. I had to by-pass the fuel around the mechanical pump because of a leak stemming from a torn diaphram, which took a few minutes. Otherwise, all I had to do was turn the pump on. It worked like a champ and I finished out my vacation. Afterwards, I wired the pump into the starter key switch and moved the pump from before the primary to between the primary and secondary filters to prevent any water in the fuel from atomizing (sp?) so that the turbine water separator wouldn't be hindered. I used the electric pump continuously for a couple or so years; however, I did notice I had to fix many little fuel leaks that crept up. I suspect they resulted from the high, unregulated pressure of the autoparts pump. I since replaced the pump with a regulated walbro (sp again) electric pump. No leaks have cropped up since. Mechanical pumps are going the way of dinosaurs. The new Cummins engine I'm putting in the boat comes with an electric fuel pump.

 

[wufibugs]

The PO mounted an electric fuel pump and bypassed the mechanical one. Has worked fine for years and eliminates the bleeding/priming ritual. After installing a second pump for fuel polishing, I am not so concerned about pump failure. There is always the concern about overall failure of the electrical system in which case the mechanical pump would have to be activated. As Centerline points out, leaving the mechanical on the engine means it has been pumping away for years so who knows what condition the diaphragm is in, and has been robbing the engine of some small amount of hp. I am wondering about doing what we used to do to cars: Remove the mechanical pump and buy or fabricate a blank for the block. Anyone seen a blank out there for for the 2gm20f? I'd keep the mechanical as a failsafe.

 

[newboatowner]

Thank you all for your advise. The pump that I purchased is working fine, certainly better than before and I seem to have solved another problem with the replacement. I had a devil of a time getting the engine to turn over. I had to jolt it with direct connection to the power line and by pass the ignition switch. I would then turn over for a second and I would reattach the line to the starter switch. It wasn't difficult by it was annoying. When I replaced the pump the problem started to disappear. It could be that the connection to the old pump was starting to fray and grounded out, drawing power from the starter switch.

As far as rebuilding the injector pump, I did have that done last year. Hanson Marine were really good and honest. The cost was reasonable.