Citroen Berlingo Multispace (1998 - 2010) - 1996, 1.9d, fuel pump/ immobiliser

Honest John Back Room » Technical matters
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Sat 22 Mar 2008 14:43
1996, 1.9d, fuel pump/ immobiliser - Andy_r
i am looking at this for a friend - he had the immobilser by-passed by his local garage. A ignition-switched supply was connected to one of two leads to the fuel-cut off solenoid - behind the cover on the lucas fuel pump. Several other wires in this region (not all) were cut at the same time. At the same time, a "miss" developed when under load.

There is a four way connector that connects in front of the solenoid. It connects to an unknown electronics module hidden at the back of the fuel pump, close to the block.
i think only one or two of these wires remain connected due to the immob bypass. When this plug is disconnected, the car does not start.

does anyone know what the module at the back of the pump is? i don't really want to take the pump off to find out, although I might have to if it is faulty. i'm guessing that the modified wiring to this component is responsible for the irregular missing when driving.

Am i on the right lines?

many thanks

Andy
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Sat 22 Mar 2008 15:13
1996, 1.9d, fuel pump/ immobiliser - Peter.N.
I don't know about it causing misfiring as all the leads only serve to open the fuel solonoid using the code so that it will run, although I didn't think you could overide it with out removing the module from the pump, which requires a bit of butchering.

How does this irregular missing manifest itself?
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Sat 22 Mar 2008 15:44
1996, 1.9d, fuel pump/ immobiliser - Andy_r
I assume the module normally just takes a digital signal from the keypad and provides a supply to the fuel solenoid. The by-pass has done this by puting a supply direct to the solenoid. that said, I'm not sure what the two wires to the solenoid do. One of them remains un-connected.

It would appear that the module on the back of the pump controls something electronically in addition to the fuel solenoid I have access to, as it won't run with its plug disconnected. The fuel solenoid opens and closes ok, I've measured V and I to confirm this on the by-pass lead.

when accellerating, the miss presents at random, reasonably frequent intervals in the form of slight hesistancy. Once lifted off, the engine runs normally.

Thanks

Andy

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Sat 22 Mar 2008 17:15
1996, 1.9d, fuel pump/ immobiliser - Peter.N.
Sounds suspiciously as though you have air getting into the fuel system, has the fuel filter been replaced recently.
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