Welcome to, The home of the PCCA => General Help- Ask the Experts... => Topic started by: cobra on December 21, 2018, 01:15:19 PM

Title: Electric fuel pump
Post by: cobra on December 21, 2018, 01:15:19 PM
I installed an electric fuel pump, ran it inline to the mechanical pump. Does the mechanical pump have free flow through it? Will I damage the mechanical pump if it doesn't? One more question. Can I run just the electric pump with a regulator on it and remove the mechanical pump altogether?
Title: Re: Electric fuel pump
Post by: Wittsend on December 21, 2018, 02:21:56 PM
Question #!. No, but maybe. I have electric pumps in a number of my cars (retrofit). Sometimes if the mechanical pump is in the correct position when the engine is turned off I will get fuel flowing through, other times not. I just think it depends on the lever position and therfore the valving position in the mechanical pump.

Question #2. Yes, but ... . If the car stalls, rolls over etc. the pump will still be pumping even though the car may not be burning fuel. This creates a fire hazzard. At the very least a separate shut off switch where the driver can reach it if needed. But that is limited to actually reaching it in an accident. Ford injected cars have a shut off shock switch that if the car rolls over or is stuck abruptly it will disengage. They are typically found in the trunk and wrecking yards sell them pretty cheap. Not sure what they cost new. Modern injected cars also shut off the power to the fuel pump if the engine stops turning for about 2 seconds. That is ECU controlled and on a carburetted Pinto not going to happen.

My own experience is if the electric pump has a low enough pressure it will just "assist" the merchanical pump and there are no issues. However, if the pressure is too high (darn those Holley Blue pumps!) I have had leaks at the mechanical pump.  I do like having both as it becomes redundant security. But, on some cars I only have the electric.
Title: Re: Electric fuel pump
Post by: cobra on December 21, 2018, 05:34:52 PM
Thank you for the input.  You hit the nail on the had. The first time I used the electric it worked fine and shut it off after the engine started. The second time I started I noticed a leak at the mechanical pump which I don't like. You sure explained the reason why in a way that made sense.  This is a kit car so a rollover or anything like that happening are close to nil. So with the leaking at the mechanical pump I would like to use just the electric pump. Do you recommend a particular fuel regulator?
Title: Re: Electric fuel pump
Post by: Wittsend on December 21, 2018, 08:03:21 PM
My experience is with the cheap $15-ish Chinese pumps. They look like the "cube" (transformer with in/out ports) pump made by Facet that are more in the $50 range. The pumps are sold in roughly the 4 PSI and 7 PSI versions. Many have said that with the 4 PSI pump they did not need a regulator. In my case I got the 7 PSI pump but I already had a Holley regulator when I used the race oriented “blue” pump. It was HORRIBLY noisy and that is the reason I replaced it.

 The cube type pumps seem to have a flow through feature so if they are not on they still allow gas to pass through when using the mechanical pump only. There are other $15-$20 pumps that look more like a stubby cigar tube and I assume they have a vane rotor. I do not know if they have a pass through feature.  My cheap pump also came with a screw on filter.  If used on an old car I highly recommend using it.  You don’t want a bunch of junk passing through or clogging the pump. I can’t comment on the durability of the Chinese $15 pump I have. I rarely drive the car once every 6-10 weeks and have only had it about 6 months.
Title: Re: Electric fuel pump
Post by: LongTimeFordMan on December 22, 2018, 05:39:01 PM
Ive had a couple of "Facet" pumps and as I recall.there are 2 types, one seems to be some.sort of rotary and the other pulses and "thumps" softly as it works.  The thumper seems to work better.. also some have a metal filter attached to the input.  The filter I had leaked air around the crimped end and wouldnt zoop gas.

Over app the thumper  Facet pumps ive had worked better than any other ive used.
Title: Re: Electric fuel pump
Post by: cobra on December 23, 2018, 07:19:24 AM
I installed a Facet that thumps quietly with a switch under the dash which works fine. I plan to put a Holley regulator in line and remove the mechanical fuel pump. I shall let all know how it turns out.