Electric Fuel Pump - Mistake?

[Go big blue]

I just purchased my first land cruiser, an 85 fj60, three days ago. Stock everything. BUT, the PO installed an electric fuel pump (incorrectly) and my first trip with the truck was to a mechanic who fixed the install. My question is whether I have already screwed up the truck by having an electric pump installed? Can I go back to the mechanical pump if so?

 

[Jesper]

The electric pump should be really easy to disconnect and remove.

Aisin / OEM pumps are easy to find and easy to install. I think I found mine online for about $90 (try Amazon or RockAuto). *Just make sure you also get the $5 plastic spacer that fits between the pump and the engine block***

Not only will you have the reliability and cool factor of the original design, but you won't have the inevitable mess of jerry-rigged wires and mix'n'match nonsense which always seem to create a ripple effect of headaches in the long run.

Plenty of threads and info here on doing it, but it's literally a bolt-off/bolt-on operation with a kiss of RTV or gasket material for good measure. Not many things on these trucks are as straight forward so take the easy wins when you can.

My $.02, anyway.

 

[OSS]

Guys installed electric fuel pumps to try to eliminate the issue of hard starts (because they don't know how to start it) after the truck has sit for a few days when the carburetor float bowl empties.

With an electric fuel pump, when you turn the ignition key, the pump starts pumping immediately and will fill the float bowl before trying to start the engine. That way, the engine will start right off without having to crank the engine over a few times before trying to start it.

The drawback to electric fuel pumps when used with a carburetor is that they could over pressurize the supply to the needle valve in the carb, causing too much fuel to enter the float bowl, which ends up getting sucked into the engine & diluting the oil. Aftermarket bolt on electric pumps are also less intrinsically reliable than OEM mechanical pumps.

The mechanical fuel pump has a return line to the tank. Electric pumps don't. Whatever fuel the carb doesn't need, the excess fuel gets pumped by the mechanical pump back to the tank. There is a constant flow of gasoline flowing from the tank to the pump and back to the tank with the mechanical pump. The fuel going to the pump therefore can be cooler flowing to the carb on hot days because it spends less time in the hot engine compartment waiting to get pumped to the carb.

The return line feature of the mechanical pump can be beneficial for maintaining the fuel quality inside the gas tank too. When the engine isn't run that often and fuel isn't getting used up quickly, alcohol blended fuels will stratify into different density levels. With a mechanical pump always recirculating the fuel, this doesn't happen.

Bottom line:
Install the mechanical fuel pump and get rid of the electric one.

 

[Go big blue]

Thanks. Do you think I️ can drive with it a while without switching it back?

 

[HemiAlex]

Go with mechanical. Get a kyosan from amazon and make sure your carb fan is working.

 

[Go big blue]

Thanks. I’m still running the electric fuel pump. It’s measuring at 7-8 psi so shouldn’t cause any damage. I definitely will switch back at some point. I initially failed smog so trying to work through that first.

 

[Seth S]

I think my truck may have an electric pump because I hear something pump like running as soon as I turn the key on. But I also still have the stock mechanical pump. I haven't had a chance to look for the sound source.

 

[DFXR]

I think my truck may have an electric pump because I hear something pump like running as soon as I turn the key on. But I also still have the stock mechanical pump. I haven't had a chance to look for the sound source.

Are there fuel lines running to and from your mechanical pump?

 

[Seth S]

As far as I can tell they are. I also don't see fuel bubbling in the filter with the key on. So if it is a pump it's not doing much. I know it's not the carb fan because it's wires are broken.

 

[Go big blue]

Interestingly the PO of my truck installed a brand new, non-OEM mechanical fuel pump, but without the spacer. It still has the yellow caps on the input and output. I suppose the install was messed up and that's why he installed the electric fuel pump.

You should be able to see an electric fuel pump mounted somewhere most likely to the left of the engine block with electric wires running to and from plus the fuel line. As far as running the electric pump, it is definitely not cool, but my mechanic told me to go ahead and keep running it for now given the low psi. If it were running above 8 he said he would go back to the mechanical pump immediately due the pressure issue pointed out by @OSS. I fully intend to go back to the mechanical pump, but I've had to put some cash into it (new plugs, choke cable, exhaust manifold seals, cat, muffler, exhaust pipe, etc.) to get it running smooth and to pass smog. Good news is that it passed smog today! I can finally get it registered. Never move to California by the way....

 

[Go big blue]

Oh, and I learned that you can fail smog in California if your gas cap isn't sealing correctly. Ordered an OEM cap from Cruiser Corps, which I had planned to do anyway, but geez.

 

[OSS]

Oh you can fail that EVAP test even if your gas cap is brand new. Start growing your finger nails now so you have something to gnaw on 2 years from now during your next test (ha!)