Pls Help Fuel Pump Not Priming... Inertia Switch

[MPoxon]

Evening all,

The fuel pump on my Griff is not priming. I am struggling to find the inertia switch is this it here just infront of the footwell vent on the passenger side?



This box has a little tiny micro switch on it but it springs back up again when pressed.

I have checked fuse 13 and I can hear relays clicking on and off.

Any advice would be greatly appreciated.

Matthew

[Russell Mc]

Might be different for a 500 but here is my inertia switch behind the glovebox. That switch your looking at seems more like one of the heater switches.

[MPoxon]

Thanks for the info and picture Russell, I have now managed to find the inertia switch.

Unfortunately it has not solved the issue

I have plugged in the Steve Heath ECU Mate and this confirms the ECU is all OK. I have also used the tool to turn the fuel pump on and off and this clicks the relay but no alas no fuel pump wirr.

[ChimpanLucky]

MPoxon said:

Thanks for the info and picture Russell, I have now managed to find the inertia switch.

Unfortunately it has not solved the issue

I have plugged in the Steve Heath ECU Mate and this confirms the ECU is all OK. I have also used the tool to turn the fuel pump on and off and this clicks the relay but no alas no fuel pump wirr.

Your fault may be the relay inside the notoriously problematic Meta immobiliser that controls the fuel pump circuit (amongst others).

Accessing and replacing the relay inside the unit is really a job for someone with experience in working with electronics.

But you can easily test the theory by completing a temporary bypass of the immobiliser on the fuel pump circuit.

The components controlled by the immobiliser are wired in such a way that their circuits are simply looped through the Meta unit.

A quick reversible bypass of the troublesome Meta immobiliser unit on your fuel pump circuit is well worth a try.

If the theory is proven then Carl Baker can offer you repair or replace options.

http://www.tvruk.tv/www.tvruk.tv/index.html

Good luck with it, Dave.

[Russell Mc]

Check the wires at the fuel pump. I had exactly the same problem as you, turned out to be a poor connection at the pump.

[BliarOut]

Pump relays? They seem to be a common failure at this age. Replace as a pair

[Loubaruch]

As suggested above,possible candidates are the immobiliser, the fuel pump relay and/or the ECU relay (metal cased Bosch units (in the passenger footwell rats nest) or the fuel pump itself/and/or connectors.

Easy enough to check the fuel pump by running a separate +ve 12 volts from the battery to see if it runs.
You can bypass the immobiliser circuits as suggested if you are familiar with electrics.

[gavgavgav]

agreeing with the above, for me there is a bad earth connection form the pump to where ever that tiny earth wire goes to. I ran a -ve to the -ve battery terminal and the pump fired up for me.

Note that the connectors get in a bad way, they are quite exposed where they are.

[MPoxon]

Many thanks for the replies gents.

I will have a look tomorrow but not being very mechanically minded it will probably end up back at the garage. At the very least I will see if I can jack the car up and check the connections.

Carl Baker fitted me one of his new Meta 3 systems last year so hopefully the immobiliser side of things should be working all OK.

Matthew

[PeteGriff]

MPoxon said:

Many thanks for the replies gents.

I will have a look tomorrow but not being very mechanically minded it will probably end up back at the garage. At the very least I will see if I can jack the car up and check the connections.

Carl Baker fitted me one of his new Meta 3 systems last year so hopefully the immobiliser side of things should be working all OK.

Matthew

Hi Matt, though mine is a 4.3 I had the same a while back. I went through a whole raft of diagnostics, eventually found the fault to be the immobiliser! There was a dodgy connection, I reterminated and hey presto the pump whirred into action. Also as other guys have stated above check/change the relays, check the connections to the pump etc. All the best, Pete

[Oldred_V8S]

Loubaruch said:

As suggested above,possible candidates are the immobiliser, the fuel pump relay and/or the ECU relay (metal cased Bosch units (in the passenger footwell rats nest)

Yep my V8S refused to prime the fuel rail when I awoke it from its hibernation period. It turned out to be the main relay (one of the metal cased ones). Swapping the two relays over gave different symptoms:

Faulty relay in pump relay socket = No pump prime but the idle control valve still worked when the ignition was returned to off position.
Faulty relay in main relay socket = No pump prime and no ICV rewind when the ignition was returned to off position.

[blitzracing]

You can drop the relay out and prize of the case. Theres nothing scary inside a relay, and it will become clear if you remove the cover. You have a sprung loaded metal plate that is pulled in with an electromagnet attached to a movable contact. Just have a good look at the contacts with a magnifying glass for burning, and you can either try fine wet and dry paper on the contacts to clean then up, or bend the movable contact slightly to change the contact point between the connectors. Nothing heavy handed however.

[spend]

There is a fuse as well as the relay

It can reside on the fly loom with the relays &/or in the fusebox.

Easy with a multimeter to test the power circuit in the fuel relay to make sure power is supplied to (& switched across) the relay - its just the two pins that are opposite and perpendicular (the 2 opposite & parallel activate the solenoid to switch).

[odyssey2200]

Please excuse my lack of knowledge but is your car a Rover V8?

If so check the oil pressure switch.

IIRC it has 3 wires.

One earths to operate the Oil pressure guage and light and the other 2 get switched when there is oil pressure.

The good news is that if you loose oil pressure your engine will cut out and not runits bearings dry.

The bad news is an oil pressure switch failure kills the whole fuel pump circuit, dead.

Took me bloody hours to fix my SD1 but a bit of wire bridging the 2 terminals across got me home

[MPoxon]

Many thanks to all those who replied... car is all up an running again now, it turned out to be the connections on the fuel pump.

Apologies for not replying earlier but have just got back from a fantastic trip to the Lake District
http://www.pistonheads.com/gassing/topic.asp?h=0&a...