A friend of mine is working on a Whipple-Charged 454. At idle the fuel pump that supplies the extra injectors doesn’t run and the fuel pressure gauge reads 0. Is the pump supposed to run all the time? If so, where does he start looking for the problem?

TTT I wish I could help, but I don't know the answer. I am in the middle of an install myself, so I'm curious because I will have the same question in a day or two if mine does the same thing. Maybe some that knows will jump in here and tell us.

I'm dealing with some similar gremlins in my aux fuel system. There is an earlier thread from a couple of weeks ago that you can look up. Here is Dustin's most recent response to my e-mail, maybe it will answer your question.

Shane,

The Whipple ECU primes the pump for 10 seconds when you turn the key on, the clicking is the relay which is powering the pump. The Whipple ECU flips the relay by grounding it, which then sends the power reference to the pump. The pump runs at all times when the motor is running.

When you turned the key off and it held 30psi, that's because it has a regulator in the system, the regulator is trying to maintain pressure, this tells me that the pump is now allowing fuel to leak quickly through it typically meaning that the internals are fine, your regulator is working. This leads me to the next question, what type of gauge are you using? Is it a Gaffrig electric gauge? These have always been off and should only be used as a reference, please install a mechanical pressure gauge, you can get them at Grainger, McMaster Carr, Orchards, etc. You need a 0-60psi gauge. This actually sounds like a gauge problem, so I would check with a mechanical gauge and run it to where you can see it in the boat, verify the proper pressure which should be between 36-38psi at all times when the motor is running. Dead heading the pump should spike up to 55-65psi on the mechanical gauge, then bleed off to nearly 36-38psi +/-3lbs when the key is off.

Thanks,
Dustin