The V8 Owners Forum -

Hi..

What it the fuel pump resistor in Rover v8 Efi?
I look at rimmer web site and i found std fuel pump resistor, and also performance fuel pump resistor? (Use with rising rate fuel pressure regulator.)
So i think i dont have this unit.. My car is sd1 with std Range Rover fuel pump in the tank.. and 2nd performance pump is outside of tank..

http://www.rimmerbros.co.uk/rimmer/rover/v8engine/pumps

So do i need the resistor? what is it look like?

Thanks..

Never heard of that before. I've got a Fuel Injection fuel pump (outside tank) with no resistor. It's a 12V pump, so that's what I hooked it up to!

Can you find anything on the SD1 wiring diagram?

Chris.

kokkolanpoika wrote:
What it the fuel pump resistor in Rover v8 Efi?

So do i need the resistor? what is it look like?

On the Rover SD1 the Efi fuel pump resistor is 1.2 ohms, purpose being to reduce pump noise by limiting pump voltage to approx 9 volts. With 3 volts dropped across 1.2 ohms, the pump current will be approx 2.5 amps.

If resistor is removed/omitted The pump current will increase by 30% to nearly 3.5 amps, the pump will run faster/noisier/hotter and provide approx 50 psi pressure, unnecessarily, because fuel pressure regulator will limit max pressure to 36psi anyway.

The extra current/load will not cause the pump to fail but it may reduce its working life.

Whether the resistor exists on Range Rover setups or for In-Tank pumps I dont know, but on the SD1 it is located beside the passenger glove box on a bracket inside the wing cavity to the left of the white relay, as seen here:

http://www.vintagemodelairplane.com/pag ... /PM04.html

or on this image:

One of the things you need to do when mildly tuning an EFi is change the fuel pump resistor from standard to one of these:

This allows a little more voltage to the pump for more fuel delivery. Good enough for the standard EFi pump to supply a 3.5 with Jag airflowmeter, 72mm throttle, upgraded cam etc.
If you're upping capacity to 4.0 plus, you have to go to bigger fuel pump and injectors.

the resistor on the early EFI , ie: flapper , is the wire that go's from coil , it says in the wiring diagram that there is a resistor but it's built into the wire = it is the PINK wire itself
the other one is one of the 3 relays near the ECU , the red one i think ??