I recently got this new roadster and going through the fuel system and noticed that it has an electric fuel pump AND mechanical (?). Maybe the pump rod for the mechanical isn’t installed and acting as a pass-through. Not sure of this configuration. Anyone ever see a config like this. Good/Bad/Ugly? All thoughts are appreciated.
I'd check to see that each one worked, and that the electric one could be sucked through if it failed. Shouldn't have two pumps, but I guess you could leave it alone until maintenance was needed.
I have the same setup (although on a sbc) My car (sometimes) sits for 4-6 weeks between startups.. The electric pump is on a separate switch, and only used for priming the carb, for an instant start.. The mechanical/std pump runs all the time, and sucks the fuel thru the electric no trouble. I would check for a switch somewhere for the electric pump.. P.S. One one occasion the mechanical pump failed on a trip, and I was able to travel over 200 mile back home, without having to fix the problem out of town..
I have both mechanical and an electric fuel pump on my '50 with an 8BA engine with stock 2 barrel carb. The mechanical pump is working whenever the engine is running and the electric pump allows fuel to pass through under these circumstances. In extreme heat conditions with vapour lock happening I turn on the electric pump to overcome vapour lock. It works very well. I would encourage you to check and see what is happening in your car to understand the purpose of both pumps.
I've run two pumps like that on a Hudson....only switched on the electric when it needed it due to going up a long grade, or being hot out.
Agree it is probably set up with a switch on the electric pump for priming after sitting for several weeks time. Minimizes cranking to get fuel up to the carb. Once primed, the electric pump shut off and the mechanical pump takes over.
Great information, wasn't sure why this configuration. The pump is connected to the ignition switch so on all the time. I may look to add a switch. Thanks all...!
Had the same thing on my avatar after installing an electric to help with starting after sitting a number of days. Didn’t seem to help much. Had the mechanical pump removed and now it’s an easy start. I think pumping through the mechanical reduced it’s effectiveness.
Crap now i have to go under truck in the morning an check the fuel pump to be safe because the two times i had the motor out this summer never thought to um thx grrrr lol
If it were me, I'd put it on a switch since it seems counter productive to have it running all the time. If you do add a switch, make sure it can handle the load of the pump, if not, use a relay.
If it draws through without trouble disconnected, leave it in. Today's fuel doesn't play well with heat. I have a glass sediment bowl on my engine driven pump- when the day is warm, the engine is hot and the fuel movement minimal in traffic, switching the electric pump on burps the vapor out of the line where it forms passing under the oil pan in the breeze from the radiator fan. It's saved me an embarrassing few moments where the car won't run. I have it hooked up to a pull switch and a tell-tale light, powered from the ignition switch. Phil
I run both kinds on one of my flatheads. Running the electric pump to prime the carb is a really big help. On hot days I can get vapor lock going down the road. I can feel it starting to happen and turn on the electric pump. In a few seconds it runs perfectly again. It can get hot enough under the hood on my '42 to bake a cake in there. I'm working on a solution to that by trying to get more cool air flow under the hood. It works really well with the hood off but that's not an option. Suggestions,anyone?
I check fuel delivery volume 'most everytime I suspect a fuel problem. I believe such a test would determine if both pumps need to be working, or not. Also answer un-asked questions about the condition of the entire fuel system including pumps, lines and filters. 1 pint in 45 seconds is a useful minimum for diagnostics. 400 HP requires quite a bit more
Back in the day, it was common for hot rodders to run a pusher pump near the tank to feed the mechanical pump. I remember helping install one on my buddy's 47 Ford when we were in high school back in the early 60's.
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