Immobiliser Troubles!

Mudgey · Post by **Mudgey** » Thu Jul 17, 2014 9:48 am

Hello Luders!

I would deffo like to bring the K20 beasty up to the national meet but am a bit worried about my temperamental immobiliser that seems to be working way to effectively! Has anybody had experience with removing immobilisers before?

Its a bit hit and miss when cold, sometimes it fires up right away, others it needs a good 5 or 6 cranks, however when its warm it almost never starts which as you can imagine is going to be a PITA at a petrol station!

How are these immobilisers generally wired in, mine seems to have about 20 wires coming from the unit! Is there a way to easily bypass or test to know for sure its definitely the immobiliser that's causing the problem?

There is just over a week remaining till the meet and its time to get this knuckled down and sorted! I think the unit is a cobra system but will find out the exact model later today.

Cheers!!

bb1boy · Post by **bb1boy** » Thu Jul 17, 2014 9:57 am

I'll be honest, it doesn't sound like an immobiliser issue to me. This sounds more lke main relay issues, mate..

Mudgey · Post by **Mudgey** » Thu Jul 17, 2014 10:08 am

Oh really? How could I check if that's the case?

bb1boy · Post by **bb1boy** » Thu Jul 17, 2014 10:13 am

Try fitting a known good one and see if your car starts in different conditions

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu Jul 17, 2014 12:31 pm

Or if you don't have a known good one available, just take out your old one and re-solder the terminals and then suck it and see...

Post by **Merlin** » Thu Jul 17, 2014 12:35 pm

Immobiliser issues could easily be interpreted as a problem with the main relay. The immobiliser would stop the fuel pump from working, just like a faulty main relay.

bb1boy · Post by **bb1boy** » Thu Jul 17, 2014 1:35 pm

^^ true, but it's the 'will rarely start when warm but starts most of the time when cold' bit that made me doubt it was a problem with the immobiliser.

Post by **Merlin** » Thu Jul 17, 2014 1:37 pm

Yup that is true as well. My 4th once had the classic main relay issue before I re-soldered it.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Thu Jul 17, 2014 2:49 pm

I've gone through the same issues with my lude (which also has an immobiliser).
Originally thought it was the immobiliser, tried different fobs, adjusted the aerial for the fob etc no joy so moved on.

I was sure it was main relay, took it apart, couldn't see anything wrong, soak tested it, couldn't get it to fail, so I refitted it but left it hanging loose and bought a good spare for next time it played up (still have it like that

) and... next time it wouldn't start, I swapped the relay and it still didn't start

swapped it back and it still didn't start, then did

Then I switched it off, swapped the relay again and it still started.

So I actually haven't got a clue what it is. I have traced lots of the wiring through for the alarm/immobiliser, but it goes all over the bloody place and I'm not sure which bits are alarm and which bits are immobiliser. I don't really want to remove them, either so I have no intention of going any further.

I agree with bb1boy though that if I were Mudgey, I'd start with main relay before drokking around with the immobiliser.

Mudgey · Post by **Mudgey** » Thu Jul 17, 2014 3:13 pm

Thanks! I'll try this first, does anybody have a part number for the Relay?