Immobiliser and fuel pump woes

[johnnyBv8]

Arggghhhhhh feckin thing won't start - obviously doesn't realise the risk of it being chopped in for something more sensible!

The problem is related to the fuel pump - it isn't priming. I've checked the relay (by swapping it with another one), fuse, fuel pump (by giving it a 12v supply) and intertia switch thing ... all are ok I think.

So, I'm guessing it's the immobiliser. If I give the relay or the pump a 12v supply then the car starts - so I want to wire in this to bypass the immobiliser as at least a temporary solution. I thought I could do this by wiring an ignition live wire to the relay...but this make the fuel pump prime continually, instead of just for a few seconds like it's meant to. I assumed that the fuel pump would switch itself off once primed, but it doesn't seem to.

Any ideas on how to get round this?

Cheers

[poorpeet]

I had the self same problem a couple of years ago. After weeks of fiddling around tracing wires etc it turned out to be corrosion in the connecter that sits between the passenger side door lock and between the wire & the spade connector the goes on the pump.
I'd check for 12v at the feed to the pump as close to the ecu/immob as poss just to be sure.

[spend]

Immob & Inertia switch (& a lot of wiring) are in between the relay and pump as standard.

[pwd95]

Got the very same thing at the mo. Pump hasn't bin priming etc & I'm getting a clunk from the passenger door machanism somewhere when I open or close the door, i.e if I close the door...1/2 a second later I hear a 'clonk' from the mechanism, as if it's trying to do something.

[johnnyBv8]

spend said:

Immob & Inertia switch (& a lot of wiring) are in between the relay and pump as standard.

Cheers Dave. Presumably then, if I wire from the relay output direct to the fuel pump then I bypass the immobiliser - if it still doesnt work then I've ruled out the immobiliser being faulty....

[Chimjunkie]

spend said:

Immob & Inertia switch (& a lot of wiring) are in between the relay and pump as standard.

Welcome back Dave

[_Dan_]

Have you got a multimeter? See if you are actaully getting voltage to the pump. Also, the spade connectors on the actually pump are very prone to corrosion. I had this problem yesterday, mind you my car has been sitting untouched for a few years!

You could just wire direct from the battery to the pump to confirm the pump is working (just power it for a second though as no fuses/relays to protect things!!)

Edited by _Dan_ on Sunday 21st September 11:24

[johnnyBv8]

_Dan_ said:

Have you got a multimeter? See if you are actaully getting voltage to the pump. Also, the spade connectors on the actually pump are very prone to corrosion. I had this problem yesterday, mind you my car has been sitting untouched for a few years!

You could just wire direct from the battery to the pump to confirm the pump is working (just power it for a second though as no fuses/relays!!)

Yep, done that cheers - pump is ok.

[_Dan_]

Working backwards from the pump then, I guess a continuity test on the itertia switch is next to see if it's open or closed.

Is it the original immobiliser fitted?