Fuel pump relay with primer feature
 

Greetings! One of my vehicles has an (aftermarket) electric pump in place of the mechanical (because the ZZ502 doesn't have a pump boss).

The pump is controlled by a standard relay, the ground of which is tied to the oil pressure switch. This way the pump won't keep running if the engine stops.

However, it's terrible in the sense it doesn't prime the carb, unless you can build enough oil pressure during cranking to trigger the relay.

I'm looking for something that's either a $10 junkyard part or doesn't exist, but I bet it does on 80s trucks - a relay that also has a priming feature, so that when it first sees Ignition power it runs the pump for some number of seconds, and then runs it once the engine is running and oil pressure is seen.

I've looked at the GM "Hot Fuel Module" but I think that's a different purpose, it seems to run the pump -after- the engine stops. Sort of the opposite of what I want.

Does anyone know, on any application anywhere, of such a timed relay? Everything I've looked at so far requires input from the ECM (computer) to do the prime feature.

Any leads would be greatly appreciated!

Thanks,
Dave

Re: Fuel pump relay with primer feature
 

Easiest thing I could think of is wire a switch to manually run it. Im sure electrical gurus could come up with a better way.
Posted via Mobile Device

Re: Fuel pump relay with primer feature
 

What kind of carb are you running? I've never heard of a carb needing pressurized fuel to start.

Re: Fuel pump relay with primer feature
 

It doesn't need pressurization (never said that), just priming if its been sitting for a while. I could do a button, but that's pretty manual, I want it to be "turnkey".

I could probably get away with having the starter trigger the relay, but a prime feature would still be handy.

Re: Fuel pump relay with primer feature
 

how about a ?? seconds timmer hooked on your ignition? plug it to a 5 point relay. turn the key to on and when the programed time period is done it gets back to your normal circuit and then crank it. go and talk about it to an electronic shop or some sort of radio shack im sure such a programable electronic device exist or google it.you might need more relays tough but its an easy setup and a good idea never tought of that myself

Re: Fuel pump relay with primer feature
 

i dont know if fuel pressure gauge with electric output exist but it could also be a good setup . like when you turn the key on it trigers the fuel pump to the desired pressure then shut the pump when the pressure is reached

Re: Fuel pump relay with primer feature
 

http://www.kennedydiesel.com/detail.cfm?ID=402

Pricy but it would work.

Re: Fuel pump relay with primer feature
 

Thanks, that looks to be exactly what I'm looking for, I'll check into it. I have the Aeromotive fuel pump controller in one of my other cars but I think they run over $300, so this might be a good compromise.

Re: Fuel pump relay with primer feature
 

I have the same issue. I was thinking about going with a roll over switch but wouldnt be covered in all situations if the motor stops running. Its done somehow. My motorhome electric fuel pump runs like an on demand. with a pressure switch I guess??
Posted via Mobile Device