Hi, does the MY99-00 simply have a relay controlling the fuel pump on and off or is there a fuel pump control unit which varies the pump speed like later cars?

If it's just a relay I gather this is one of the the silver round metal cylinders near the dash fuse box?

 

If you are having fuel pump issues, it cuts out when warm and wont start for about 30mins, itll be the immobiliser relay that is spliced into the main pump wiring, do a search tonnes of stuff on it. You xant get access to immobiliser relays as they are in a sealed unit but you can bypass the fuel pump one by tracing the wiring from pump to up under dash. Remove it and bridge it. Immobiliser will still work and immobilise via starter

 

It's actually not a fault, I'm trying to work out how it works as I'm building a car with a 99-00 loom. I know the later cars have an actual fuel pump control unit which varies the pump speed but I need to know if the 99-00 cars have this or if it's just a case of on/off via a relay.

Thank you for the reply. I do need to rip the sigma out of the loom too.

 

Well after a bit of research it looks like the pump is controlled simply by a round metal relay under the dash near the fuse box. The sigma is spliced into the feed to or from this relay. There is no FPC. It looks like the FPC is only on later cars.

 

Hey, There are several FPC choices out there. I have tried couple and right now I am using an FPC controller from dccdpro.com and it works very close to OEM type but with more juice. the only difference is that it has optional analog input (for models that don't have ECU support) to control it with signal from TPS or mass airflow sensor.

 

Thats correct for the Impreza, but, for example, the MY99-00 Legacy TT does have a FPC which is used. The ecu looks the same as the Impreza but there are additional pins utilised

cheers

bob