rangey - power to fuel pump problems

[weaves]

hi guys,

i've spent the best part of my working week using the search function trying to solve this problem. but cant narrow down any specific causes.

the car is a 87 Range Rover. 3.5ltr injected.

from day one this car has been nothing but problems. First it was the ignition. so in went a new dizzy. rotor button. leads plugs and coil and bingo problem solved for all of a month.

then the reaccuring problem of it surging and sputtering to its final demise at sugarloaf a few weeks back.

we had the problem narrowed down to muddy water in the tank making its way through the filter to destroy the pump.

to fix this we have replaced all rubber fuel hose. flushed all metal lines with brake clean. we have replaced the fuel pump, filter, fuel pressure regulator and resealed the tank sender to help prevent this happening again. with all eggs in this basket the turn of the key reveals that the pump not making a sound. running out of light i did a quick hardwire of the pump to hear it buzz away nicely.

we have also checked all fuses and relays.

this car has a carby tank with an external pump from factory.

has anyone came across this problem before? does anyone have any ideas of what i should be checking?

i'm thinking about just hardwiring it to the batter via a switch mated to a accesories wire.

any ideas

weaves...

[lokka]

Yep sounds like it could be signal from the ECU causing dramas think i spoke to you about this the other day while having a fone convo about bearings PMme if youy need more help as it can get fairly involved with the early EFI its crap carbs are far better or LPG ..

[weaves]

yea that was me at Bearing Dynamics.

we have a auto lecky mate thats going to come around sunday if we can't get it going saturday.

fuel pump signal from the ecu is Brown/white wire? thats best i can figure by searching on here and without having a diagram to go off.

would removing this by hardwiring it affect the ecu at all?
will it make it go into a limp mode?
does the ecu need this signal for the injectore pulse?

cheers
weaves

[cloughy]

Fuel pump turns on via the flapper, hard wire it and see how you go

[Loanrangie]

No EFI rangie had an external factory fitted pump, have you fitted a different pump or relying on the low pressure factory pump ?

[armbrup]

The older Rover injections had 3 controls on the fuel pump.
1 The ECU earths the pump relay .
2 The Federal injection had a timer relay which went for 2-3 seconds on cranking. I THINK the Flapper injection also has this. If not the ECU will ground for 3 seconds like the 14CUX.
3 Once the car starts The flapper opens and turns on the pump. This is also a safety thing.
4 everything goes through the inertia switch which cuts off fuel if you crash.

The way to check is to start at the pump terminals, to see if any power.
Then to both sides of the inertia switch.
Then back to the relay.
I reckon you will find either a bad inertia switch, bad relay or poor contacts somewhere along the line.
or maybe a bad contact from the flapper. lift the flapper manually a bit and the pump should start with ign on.
Regard sPhilip A