Thread: V8 Discovery Fuel Pump Prob

Go The VL Bosch Pump!!!

Lrh

Originally Posted by muddydigger

$100 from JAG RANGE ROVER spares at Kedron

Thats cheap, doesn't sound geniue part ! and doesn't sound like a new one !

Originally Posted by GrahamH

Remember that the pump only runs until it has pressurised the fuel rail and then shuts off until the injectors draw fuel off the rail. So it is normal for it to run for a short time then stop when you turn the key to ignition without starting the engine. (This is handy when running on LPG as the pump doesn't wear itself out but fuel is available to injectors immediately on changeover!)

A bit late on this thread but the info is still top quality
I am about to replace my pump, which as stopped working. It sits in a 30l sill tank due to LPG conversion. Because of this the sound is not baffled as much and is always apparent. Herein lies my confusion. It never switched off as I recall. I often wondered why they (the LPG installers) didn't incorporate some dohicky to shut it off when on LPG.
When I install the new one, I will do that. I am concerned that it may trigger something in the ECM but we'll see.

Ralph

Originally Posted by Ralph1Malph

It never switched off as I recall. I often wondered why they (the LPG installers) didn't incorporate some dohicky to shut it off when on LPG.
When I install the new one, I will do that. I am concerned that it may trigger something in the ECM but we'll see.

When I spoke to an LPG installer about this I was told the pump needs to keep running to cool the fuel rail. Also something about fuel going stale or gumming up?

Originally Posted by Utemad

When I spoke to an LPG installer about this I was told the pump needs to keep running to cool the fuel rail. Also something about fuel going stale or gumming up?

Yes of course!
That makes sense. I often have stale fuel issues as it only starts on petrol not runs. I might leave it as is just put a switch to manually turn it off on long trips or when the tank is near empty and the noise is louder.
Thanks
Ralph

not so much gumming up but cooking the addatives into the fuel rail. When you restart the pump fresh fuel comes in and will generally wash them away. When this happens you cant guarentee that the left over bits will mix cleanly which means you might get some crud in a jelly state entering the injector causing problems...

IMHO I agree with leaving the pump running when on LPG but dont think that it needs to be on full steam as all its doing is flowing fuel around to stop it from being cooked into the main supply rail. The downside to that is the pressure regulator which needs to be opened up by fuel pressure to get the fuel to return to the tank which means the pump needs to be on full steam... Hrm bit of a catch 22..

and no turning off the pump and running the engine till the fuel is used up(like you do on a carby lpg duel fueler) wont work as the injectors rely on the fuel pressure to squirt it out, once the pump is off the pressure drops very quickly and leaves a lot of residual fuel in the rail and since its not under any pressure will cook even quicker than if you just turn the pump off and then turn over to lpg...

Originally Posted by muddydigger
$100 from JAG RANGE ROVER spares at Kedron

Originally Posted by matbor

Thats cheap, doesn't sound genuine part ! and doesn't sound like a new one !

Muddydigger, did u find out if it was a genuine part ?