Mechanical or Electric Fuel Pump

[lwb66step]

What is the benefit if any of converting the fuel pump in my '63 L6 230 from mechanical to electric? The electric pump I found for $20 more than a new mechanical pump, is it worth the extra money to convert to an electric pump setup and has anyone done this conversion?

[markeb01]

I’ve run many electric fuel pumps over the years. Each time it was because I could not fit a mechanical pump (engine swap related). And eventually, I had trouble with every single one. Compared to a mechanical pump, they seem prone to failure regardless of brand or style. On my GMC I was determined to use a mechanical pump. The engine has somewhere around 150,000 on it now and is still running the original pump installed in 1991.

Many carbureted engines are hard to start after sitting for several days because the new fuels evaporate from the fuel bowls, leaving the carburetor out of gas. One benefit of an electric pump is it primes the fuel system as soon as you hit the ignition, so starting may be improved. The downside, the system really needs the addition of a crash/rollover valve to shut off fuel in case of an accident, and these can be expensive.

Also – some people like the racket of an electric pump, while others hate it. Different brands make more or less noise depending on engineering design, but most are very noticeable. Personally I’ll never run another electric pump.

And of course all this applies to old school low pressure pumps. Late model fuel injected cars all have high pressure electric pumps, and there really isn’t any other option.

[Clyde65]

What he ( Markeb01) said!!!!!

[lwb66step]

Thanks for the advice, I believe I will be sticking with the old mechanical fuel pump, i don't understand why my old one is not getting fuel from the tank to the carb, i drained the tank and then added some fuel system treatment and put like 3 gallons in it and after about 30 mins of trying to start the truck, i pulled the fuel line from the carb and the bowl was dry as a bone, so no fuel is getting from the pump to the carb, but then i checked the line from the tank to the pump and it seemed dry also. Then I pulled the pump apart and it was full of what smelled like very old gas, but the pump should still work even if it had old gas in it seeing as it is mechanical. Should I be looking into low oil pressure as the culprit? That is to say, could a lack of oil pressure cause the mechanical pump to fail? I just dont want to replace the pump when I should be replacing the oil pump. Also, it could be a clogged pickup as well right? Any help on this would be appreciated, I have the funds to get this truck running if I had more knowledge on where to start it would really help. Truck has the 230 L6 engine and is a '63.

[markeb01]

The easy way to check the pump is disconnect and plug the line coming from the tank. Connect a new rubber hose to the inlet side of the pump, and place the other end in a can of gasoline somewhere close by. (The can doesn't need much gas in it, you just want to determine if the pump is working). With a fire extinguisher nearby, see if the carburetor now gets gas when cranking. If the line beyond the pump remains dry, you need a new pump.

[lwb66step]

so, i pretty much did this except I just kept the line from the tank still attached but with the line still connected to the tank I wont be able to tell if the pump is bad or the line is clogged.....I will try this after work and see what happens

Thanks!

[Tx Firefighter]

Your oil pump has nothing to do with your fuel pump.

You've likely got goop built up on the fuel pickup in the tank.

[lwb66step]

i thought the fuel pump operated on oil pressure from the block. is this not correct?

[markeb01]

The small block Chevy mechanical fuel pump has a diaphragm that is operated by a lever on the engine side, which is driven by a heavy push rod running against a cam lobe specifically designed for the fuel pump.

Oops just realized you have an inline 6. Same principle, but I don't remember if there is a push rod in between, or the pump lever runs directly against the camshaft.

[lwb66step]

ok so oil pressure does not power the pump, (duh, that would be a hydraulic pump) it is powered by input from the cam, hence the term MECHANICAL.....ahhhhhhhhh....i see now. Thanks for explaining to me.

[wildearp]

The biggest advantage to an electric pump is on vehicles that aren't driven often, or that sit over two weeks at a time. They immediately pump up your carb bowl so you don't have to crank it excessively to get it to start. As long as you install your electric where it is easily accessible and not exposed to exhaust heat, it will have a long life. Always install a prefilter on them.

I recently was working with an unrelated issue and remounted an electric. It had a lot of aluminum debris in it from a brand new fuel tank. It didn't hurt the pump, but easily could have destroyed it. I installed a large Fram filter before the pump. If I hadn't relocated the pump, it would have been a real nightmare servicing it while on the road. Now it is super easy to get to.

[1971 GMC SHORTY]

Mechanical--- ever Electric pup ive used, red, blue holly never out last Mechanical.. Just my 2 cents

[lwb66step]

I am def sticking to the mechanical pump. much more reliable according to most everyone. I am holding out hope that my pump is ok and I just have a clog somewhere between the tank and the pump, hopefully I can get it sorted out this weekend~

[61_FL_Apache]

Originally Posted by 1971 GMC SHORTY

Mechanical--- ever Electric pup ive used, red, blue holly never out last Mechanical.. Just my 2 cents

[El Campo]

Wildearp, not trying to jack this thread but how long of hose can u have before u have the filter and pump? Can the filter be 3 feet from the tank (tank is inside bed and is gravity flow to the filter) and the pump be further yet?
Posted via Mobile Device

[Mechanic77]

Something else to check is the rubber fuel lines themselves, if they are old and cracked, you can have a situation where the fuel pump will suck air instead of fuel......best to just replace all the rubber fuel line between the tank and fuel pump with new

[markeb01]

Originally Posted by El Campo

Wildearp, not trying to jack this thread but how long of hose can u have before u have the filter and pump? Can the filter be 3 feet from the tank (tank is inside bed and is gravity flow to the filter) and the pump be further yet?
Posted via Mobile Device

The general rule with any electric pump is mount it as close as possible to the tank. They are very good at pushing, not very efficient at sucking. If it's below the tank with gravity feed that would help, but the pump should still be as close to the tank as you can mount it.