Hi all, I am running two inline fuel pumps, the secondary pump is governed by a 2psi switch turning on pump at 2psi boost and a time delay for turning off to stop unnecessary "cycling"

EFI fuel pressure is normally at 59psi - would it be feasible to use a fuel pressure (55psi) switch to turn off ignition if fuel pressure for some reason would be under 55psi ? As this pump only turned on occasionally you never know if it's going to work ! Trying to safeguard my expensive toys - LOL Switch would be connected to a picaxe micro controller and a relay to cut off ignition.

Or anybody have any other suggestions - any response greatly appreciated !

Engine: 502 chevy, S-480 single turbo, Fitech 1200HP EFI

 

Yes, second switch power is activated by first switch power after a delay. Second switch is normally closed wired into coil relay ground or positive switched input, I think you get it from there. This does seem like a sort of odd way to protect something in a boosted application, since your pressure needs to rise with boost (so if your running 14 psi you really should have 73 psi pressure), at 55 psi your fuel pressure deficit could be pretty significant.

 

Hi Ben thanks for reply: If second pump won't turn on - 59 psi is probably close to the 600 hp mark (NA hp) pump only good to 600 so the sensor is not going to need to be 1:1 as switch only will see 1 to 2 psi of boost and run out of stem and loose pressure - that's my thinking

 

Can't the EFI controller do that based on AFR or sensor feedback or something? What is is the picaxe for?

 

High there 65shelbyclone, answer is simple - the Fitech controller is very simple, need the picaxe to read the 0-100 psi pressure sensor and activate relay - Fitech does not read fuel pressure as such - got the controller when swapping parts - going to give it a go....