Author Topic: Golf MK3 - Running issue, immobilizer?  (Read 574 times)

Offline PeterByrtus

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Golf MK3 - Running issue, immobilizer?
« on: 21 February 2020, 13:30 »
Hi guys. So I've had 6 MK3 Golfs in total. I had a silver estate for about 2 years that was originally a 1.4 Petrol (Living in Ireland) that I swapped to a 1.8 8v Petrol from a donor car. I drove around it for a little over a year just as a beater car. Early last year, I decided to scrap the shell as it was rusty. I picked up a very clean metallic red hatchback, once again with a 1.4 Petrol. Before I scrapped the estate shell, I removed the engine/trans, axles, ecu loom, ecu and the clocks.

I just finished swapping the 1.8 into the new hatchback shell. Have the basics in, engine/trans, ecu loom and ecu. No coolant hoses or anything as I just wanted to start her up since I did a head gasket/timing belt whilst the engine was out. Sooo, the lights come on, engine starts for about 2 seconds and dies. If I hold down the gas pedal, it will rev when started but again, dies in 2 seconds. Many people told me it would be an immobilizer issue.

I am using the 1.8 ecu with the 1.4 key, immo chip/box. I don't remember swapping out the immo in the previous swap (unless I did) soo did I f*ck this up. Should have I kept the little ring around the key barrel and the box? I have the key with the chip from the previous car, swapped the chip but still the same. Do I need to source all new ecu/keys/ring or can I still make this work? Thanks very much, really need to get this going soon!!

Offline Pete le Deet

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Re: Golf MK3 - Running issue, immobilizer?
« Reply #1 on: 21 February 2020, 15:56 »
That is the symptom of the immobiliser operating, Peter. And unfortunately the 'set' of matched components does include the small black box fitted above the pedal box (it's engine ecu, immobiliser box and key chip(s)). The 'reader spool' fitted around the lock barrel isn't coded, but failure isn't unknown.

The ways I'm aware of around it are;

 a) acquire another set of components for the 1.8 engine, taking care to get one for the right engine code
 b) have your 1.8 engine ecu de-immobilised
 c) get an auto locksmith/diagnostic specialist to match the 1.8 engine ecu to the 1.4 immo. box and chips