holley (red) electric fuel pump question?

xlargest

Veteran Member
Feb 23, 2016
106
las vegas, nv
Replaced my holley red electric fuel pump couple months ago with another one and I've had no problems with it. The other day went to start the 72 camaro and it would crank but no start. Checked for spark and I have it. I checked my battery voltage and I had 12 volts, so I decided to charge it...at full charge I had 13.4 volts. I don't know if my CCA in the battery is going bad or not, I need to get that checked, I think it should start even at 12 volts...
I went to try to start the car again and it started. I may have a voltage mystery drain but that's another issue. However...

My question is you can hear the fuel pump come on when ignition is placed to on but when you goto run you dont hear it anymore until after it fires. I have 6 psi when ignition is placed to on but during start you see pressure decrease to like 2 or 3 psi, is this normal for the pump to not run after initial start but comes back on during run? Is it normal for pressure to be low during run? The pressure goes back up too 6 psi after.
Thanks! Hopefully this makes sense.
 

camarolife78

Veteran Member
Jul 22, 2014
549
Gardner, KS
Check your ignition feed to the fuel pump. It should stay hot during cranking. If it does not, its not hooked to the correct part of the ignition. Switch it to a power source that stays hot during crank.
 

grzewnicki

Veteran Member
Lifetime Gold Member
Dec 9, 2009
3,781
Gordon from Jacksonville Fl
Not trying to be a dick but I am really wondering why the pump needs to be on during cranking, I understand if you have fuel injection that would be the case but for a carb car??? There is enough fuel in the carb bowls to run for probably a minute till they are dry. If you want to make sure the bowls are full, you can turn the key on, wait 10-15 seconds then start it, the fuel level in the bowl has dropped a miniscule amount by the time you have the key in the run position and the pump is on.
 

CorkyE

Veteran Member
Lifetime Gold Member
Nov 4, 2004
11,929
Ringgold, GA
Not trying to be a dick but I am really wondering why the pump needs to be on during cranking, I understand if you have fuel injection that would be the case but for a carb car??? There is enough fuel in the carb bowls to run for probably a minute till they are dry. If you want to make sure the bowls are full, you can turn the key on, wait 10-15 seconds then start it, the fuel level in the bowl has dropped a miniscule amount by the time you have the key in the run position and the pump is on.
Exactly - this is the way I start mine. Flip the pump off to give the starter a bit of an advantage.
 

xlargest

Veteran Member
Feb 23, 2016
106
las vegas, nv
Okay, I was going to wire it to the back up dir sig sw circuit which is tied to the ignition terminal tab on the fuse box so it would be running on ON, START and RUN but its prolly just fine being wired the way it is as long as I run the elec fuel pump for a little before start.
 

muscl car

Veteran Member
Lifetime Gold Member
Jul 8, 2001
24,034
Gallatin Tennessee
When I had an electric fuel pump quite a few years ago and before starting . I would turn the pump on and once I saw fuel press on my fuel press gauge I turned it off . Then once the engines running I would turn the pump back on
 




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