Thread: Further to my car not going

Originally Posted by PhilipA

May I quote form Haynes workshop Manual Range Rover 1970 to Oct 1992 13.24 Supplement :Revisions and Information on later models.
PART C: Fuel injection system (Lucas L) IE flapper
PARA 5
"The control system must be considered to include the fuel pump. The pump is wired in such a way that it is only energised when the ignition is switched on and the engine is running, or when the starter motor is cranking.
An inertia switch , in series with the pump , stops the pump operating in the event of an accident involving impact"

Jeeeze.
Look I have installed a Federal System on a carby car and have a 3.9 .









































































































Both systems have both an inertia switch and a timer for cranking. I can see no reason why the 3.5 flapper would be different. AND the manual agrees.
I know everyone is trying to be helpful but incomplete or wrong information doesn't help.
While I haven't actually worked on a RR flapper, I have attended an accident where the inertia switch tripped in a 3.5 and it wouldn't start.
Regards Philip A

PS . have you checked fuse 18 or changed another fuse in? The fuse is shown on the wiring diagram as last port of call befor the pump. The wiring diagrams are VERY frustrating . The ones I have are for the later system and the Haynes ones are almost useless for Flapper as they seem to be for carby cars.

Well after a day of confusion the beast finally runs as it should. All fuses OK, all relays OK, all connections OK. Finally ran a wire from ign to pump relay and presto, she works. Only conclusion to arise is that a wire is broken or broke[as it was running] between the power source and the relay. All there is to do now is to put the dash and other bits and pieces back together. A tomorrow job, I think. Many thanks to all who helped. Bob

Phillip,
I have completely removed the efi including wiring loom from my 3.5 motor. There was no inertia switch at all.
The fuel pump relay runs for around 3 seconds and then shuts down unless there is a signal from the flapper.

Ian

Phillip,
I have completely removed the efi including wiring loom from my 3.5 motor. There was no inertia switch at all.

Did you buy the car new? Maybe someone took it out as appears with the toggle switch in Bob H's. However as I said I have never had a 3.5 apart , but I think it is an ADR requirement. However a P6 had one, a 87-89 USA 3.5 model had one and a 3.9 had one so it is unlikely that an Oz spec 3.5 wouldn't. If you removed the wiring loom to the ECU , you wouldn't find it,as it is under the passenger seat (usually) and in series to the fuel pump, not in the ecu loom. They sometimes give trouble so may be removed by dumb mechanics who like to see bonfires.

The fuel pump relay runs for around 3 seconds and then shuts down unless there is a signal from the flapper.

.

As I said and Big Jon disagreed with. I don't know how a car would start with no fuel.

Regards Philip A

Originally Posted by PhilipA

.

As I said and Big Jon disagreed with. I don't know how a car would start with no fuel.

Regards Philip A

When you crank the engine it draws air in.

The air being drawn in opens the flap in the airflow meter.

When the flap opens it tells the fuel pump that it can operate (via the ECU I assume).

No need for an inertia switch because if you crash and the engine stops, the flap closes and the pump won't run.

I know that the 3.5 flapper fuel pump won't run on first ignition "on" because I HAVE worked on them and I DID own one (now converted to 3.9 with 14CUX which does run the pump briefly with first ignition "on").

It is easy to test the fuel pump operation with a flapper ignition.
Take off air intake duscting.
Turn ignition on.
Manually open flap in airflow meter.
Listen for pump operation.
No pump = system fault.

Interesting all this fuel pump bit..... On my flappy efi you can hear the pump run if the auto is shifted any away from Park or neutral and hold the key in start position. Obviously the engine wont crank.... The fuel pump will run happily so long as key if held in the start position. Always has done this Seems the airflow meter does not control the fuel pump with mine on start.

Tony

Probably not relevant, but I had a fuel pump wire short out on the gearbox.
No pump - no go.

It also took out the coil wiring and caught fire. mmmm hate the smell of burning wiring.

When you crank the engine it draws air in.

The air being drawn in opens the flap in the airflow meter.

BigJon, I don't disagree about the flapper but in addition the "Federal' injection I fitted to my 77 had a vastly expensive timer relay which operated the fuel pump for a short time on ign on. The Federal is very similar to the 3.5 except for the plenum, although I think the ECU controls the timer as in the 14CUX.

Every Bosch style injection I have ever had anything to do with has had a priming/pressurisation cycle , and does not then resume fuel flow until start to minimise flooding. I must again admit I have never looked in it when cranking but I believe that the flapper does not open on cranking as there is insufficient airflow.

BTW the fuel could still leak from the return pipe in an accident where the engine continued running or the wiring shorted on the flapper. The SD1 definitely had an inertia switch with the flapper as I remember agonising whether I would pay lots of money for one and decided to risk it.

BigJon, and you don't think the Haynes manual is correct? It specifically mentions both inertia switch and cranking in the general description of the injection. See above.

Also see Rangier Rover's reply.
Regards Philip A

Bit of a misunderstanding it seems .

I have a Land Rover V8EFI Electronic Fuel injection Service Training Manual ( Publication No SMR 679 TM ) .

It`s concerned with Range Rover Flapper System .( have LR HotWire also )

Ignition off pump doesn`t run .

Ignition on pump doesn`t run .

Ignition to crank pump does run .

It says the only time the pump runs being ignition initated is at crank .

During crank enough air to move the flap 5 degs which in turn closes the contacts in the airflow meter ( flapper ) which after some traveling eventually runs the pump .

So at crank both the ignition and airflow meter can run the pump .

Australian Range Rovers that used the flapper system don`t have an inertia switch ( Yes , if what typed is what Haynes Manuals say then they are incorrect ) .

The Federal system was never a factory Range Rover fitting .

SD1 V8 cars may well have had inertia switches , i know V12 Jaguars with a simialr system did . Both ran carbs on these motors before they fitted EFI . ( got some factory on Jag EFI )

P6 Rovers didn`t have EFI so don`t think they had them .

In Australia it may have been something to do with the commercial label that Range Rover got but they didn`t get inertia switches when EFI was fitted , they are fitted with the 3.9ltr engines and a different EFI .

The Australian Cars with the Rover V8 that used a similar EFI to the first RR system did/do have inertia switches .

The Hot Wire EFI fitted to Range Rovers with the 3.9ltr also does have the inertia switch .

Sorry about the change in type , can`t drive a computer very well and now the underline .

Cheers