Fuel Pump priming time?

[karolko]

I would like to know what controls the fuel pump trigger wire voltage? You know the priming of the pump for a couple of seconds before you fire up the car? I cannot seem to get any voltage to it.

Does the ECU control the timing of the trigger wire? Does it also send out the 12volts?

thanks guys

 

[jasjamz]

Yep, the ecm does. Are you getting the SES light when you turn the key on?

 

[karolko]

I am running XFI and it is currently not plugged in. As for SES lights, i have made up a custom dash and i have eliminated all those lights.

How long is the factory ecu suppose to trigger the fuel pump for before the crank signal takes over?

Thanks

 

[novaderrik]

i think it just primes it for a couple of seconds to build up pressure, and then waits for the engine to reach a certain rpm before kicking the pump on again.

 

[bmackinnon]

i think it just primes it for a couple of seconds to build up pressure, and then waits for the engine to reach a certain rpm before kicking the pump on again.

exactly... 2 seconds I believe.... ecm powers (grounds?) the fuel pump relay during the prime....

 

[turbojd]

exactly... 2 seconds I believe.... ecm powers (grounds?) the fuel pump relay during the prime....

X2, and if it's not priming for about 2 seconds check your fuel pump relay, passenger fender, and if you have a hot-wire kit to the fuel pump check that relay also. You should hear the pump prime with the key in the "on position"

 

[karolko]

Awesome thanks guys. I will plug in the XFI and make sure that both the relays are working before i begin to sweat.