How to rule out/confirm immobiliser without having to buy a new one?

[candikid]

My car suddenly stops while driving. If I'm lucky, I can just clutch, and the car is running again by the time engine has reached idle rpm. It can happen six times in a mile, and it can happen once every six miles, completely random. Paperclip test shows 145 immobiliser (was that no signal?) and MAF sensor, whatever code that was. That might be an old code though.

Anyways, I am truly sorry for making yet another thread about these bloody immobilisers, I just need to confirm (or have you confirm) that I should go and buy a new one.

Searching didn't really do the trick for me when trying to find a walkthrough on the actual swap of immobiliser, could someone link me in the right direction please?

Thanks

[TheBoy]

I think you want to be looking at ICV first...

[candikid]

ICV just checked, everything mechanical is clean and sliding freely. Resistance measured at 9.9ohms, anyone knows what to expect?

Think I should rule that one out.. What about the immobiliser now, does it seem like it could be what's causing my intermittent and very short lasting stops?

[TheBoy]

Pretty certain immobiliser will only stop it starting, not causing it to stall.

[candikid]

Aha, I see. So if I was able to take the key out of the ignition with the engine running, and went some place far away, the car would not stop? Maybe I should open my key, start the motor, go some place with the little chip, and see if the motor stops? That would definately rule out the immobiliser if it kept running, right?

[candikid]

And might the maf sensor be what's causing the stalling then? Can a faulty maf sensor make the car stall while driving, and can I check if it's faulty or not somehow?

[dbug]

Yep maf sensor could cause this - disconnect maf sensor and see if any different

Any codes?

As said immobiliser issues will only stop car starting, won't cause car to stall.

More likely dodgy crank sensor

[candikid]

Disconnected maf and it hasn't stalled all day and just went to pick one up,but it's too late to replace now, so I'll let you know tomorrow. Thanks for all your help so far!

[TheBoy]

Given the age, is it a IR locking system, or RF locking system?

[candikid]

It's an IR, I'm pretty sure. Haven't seen that thing in ages though, it didn't work when I bought the car.

[candikid]

Changed the maf sensor today. The car didn't stall for the five minutes I got to drive it, but the EML came on again after a few minutes and stayed on...

[Andy H]

It's an IR, I'm pretty sure. Haven't seen that thing in ages though, it didn't work when I bought the car.

If it starts without using the IR fob to disable the immobiliser I would assume that either someone has hacked the wiring to bypass the immobiliser or the immobiliser is faulty.

If the wiring has been hacked then there may be some poor connections. As stated above though the immobiliser is designed to stop the engine starting and not to cut the engine once you are moving (as that causes a hazard for you and other road users). Not sure whether that logic is in the immobiliser or in the engine ECU. If in the ECU an intermittent immo signal wouldn't cut the engine. If the logic is in the immobiliser then poor connections would stop the engine.

[candikid]

I see what you mean, and I'm starting to think this quest has just begun 

What anyone happen to know where (geographically) on the car that sort of wiring would take place, if it has been done?

Oh an btw, is the immobiliser the electronic thing stuck to the back of the ignition switch barrel?
I'm just gonna have to start replacing more things...

[Andy H]

I see what you mean, and I'm starting to think this quest has just begun 

What anyone happen to know where (geographically) on the car that sort of wiring would take place, if it has been done?

Oh an btw, is the immobiliser the electronic thing stuck to the back of the ignition switch barrel?
I'm just gonna have to start replacing more things...

Early IR (infra red) remote/immobilisers had a dark dome up by the rear view mirror/interior light. Pointing the key fob at the dome and pressing the button unlocked the doors and released the immobiliser.

Later cars have the wireless/RF (radio frequency) system where a circuit board in the key fob communicates with the central locking to open the doors. The immobiliser is plastic collar around the ignition barrel which uses (a different) radio frequency to talk to a tiny chip (also in the key fob).

The systems are totally different, going by the year of your car I would expect yours to be IR therefore the immobiliser is part of the locking system (and not on the ignition barrel)