mpi immobilizer problem

[mini1994]

Hi ,
I was helping my friend to paint the engine on his mpi 99 and when we put the car together the fuel pump and the starting motor dont work when i turn the key , would it be the immobilizer cutting them off ?
Thanks

[woody]

Sounds like the immobilizer or relay modual. Is the red LED on the dash switching on and off with the key fob? If it is check the connections to the relay modual on top of the servo.

[mini1994]

Thanks for your reply Woody ,
The key fob works as it turns the alarm on and off , but when i turn the key the led doesnt stay on constantly as it used to and the connection on the relay seems ok

[DOUGAL]

If u had a problem with immobilizer the engine should still turn over With no spark and no fuel pump running.
I think u are missing a power supply to the relay box .
Re check the connections at the starter as your relay box / fuse box and ign switch are fed from there .

[woody]

No the MPi immobilizer has two outputs, one prevents the engine cranking and the second is a digital code to the ECU which in turn controls the fuel pump.
I presume you haven't changed either the ECU or immobilizer as they are a matched set.
I had a simular problem to this which turned out to be a problem with the connector on the immobilizer. Power was going into the connector but not onto the pin into the immobilizer. Somebody had probed the connector and widened it making a bad contact. Its something Rover brought up in there technical bullitons for there garages.

[mini1994]

No i didnt touch the ecu or immobilizer , im going to get a diffrent relay to check will it be ok , will pluging the connector on the immobilizer out and pluging it back in help ? Thanks for your help

Patrick.

[woody]

Me thinks we better go back to the start. When you were painting the engine bay what exactly did you do ie. move/remove any items, dissconect anything, change any parts. Was any other work carried out on the car at the same time? How long was the car off the road?

[Dylan8660]

Sounds like a bad earth to me, check engine to body strap and battery to body strap.

[mini1994]

The car was in the garage for about 2 weeks ( battery was disconnected ) , nearly every think was taken out ( such as servo, injection, the sensors going into the engine , the ignition coil, just the side with the ecu wasn't touched ,
There was a new manifold and exhaust put on it , would it have somethink to do with the sensor on the manifold ?
And when i think about it the earth strap was put on under the black plate that holds the engine steady and not on the top of the bolt like it was , would that stop the fuel pump and the starting motor from working
Thanks for helping

Patrick.

[woody]

A bad earth on the engine may cause poor cranking but not the other symptons,make sure there isn't fresh paint under the earth connection. I remember when we rebuilt Billy's MPi after a respray we had major problems with the earths on the wiring loom in the engine bay. One is above the ECU on the side you didn't touch and the other is under the expansion tank on the passenger side.It took several goes to get a good connection on both.
What exhaust manifold did you use and where is the lambda sensor located in it?

[mini1994]

Got it sorted , the plug blue plug that goes to the injection was plug into the relay and the black one that goes to the relay was pluged into the injection , thanks for the help

[woody]

Good to hear you got it sorted.
Still interested to know what manifold and lambda sensor location you have.