Page 1 of 1

Electric primer pump

PostPosted: Wed Jun 29, 2022 9:22 pm
by rgalajda
Just wondering if anybody has had experience with an electric primer pump for a mechanical fuel pump. The reason I ask is because people are saying there car won't start with one pump of the accelerator after the car sits for a week or two. The problem being is that today's fuel evaporates from the carb after extended intervals of non use such as two weeks requiring cranking of the engine to refill the fuel bowls.

Re: Electric primer pump

PostPosted: Thu Jun 30, 2022 5:39 am
by GTO Geoff
Yes,
I know of this being done, but I don't like the idea & would not do it. The mech pump is designed to draw fuel without too much restriction in the line. Ok for starting but I wonder if pump performance is compromised at higher rpms on a perf engine when max fuel delivery is reqd.

Re: Electric primer pump

PostPosted: Thu Jun 30, 2022 7:46 am
by Right hand drive
I did look into it and even bought a small inline pump and some fittings. Like Geoff said the mechanical would like as free flowing as possible feed line. Although the mechanical could pull fuel through some of the inline pumps I didn’t trust it could be enough flow. I planned to put a Y piece before and after the pump for full flow around it during normal operation and a switch for the electric pump for when needed. The bypass would need a one way valve to prevent the electric pump pushing some fuel back through the bypass line. All up I abandoned it mostly due to cost v benefit as I was to use all -8 AN fittings (would have been $500+). It could certainly be done cheaper but I’d think the bypass line around the pump is necessary.