Gti 8v that only runs for 2sec

[bongosworld]

I have a mk3 2.0 8v gti that will start no problem but will cut out after only a couple of secs. I bought the car with a blown head and replaced it with a second hand one. It now does not want to play!!!!
I have checked the signal from the hall effect sensor and thats ok, I checked the signal going to the coil with a LED and well, There is a normall flash when the car starts but then you get one big bright flash then nothing, car dies. It kinda sound like there is some sort immbizer problem.

[kite]

Your right, immobilisor problem !!

[bongosworld]

Thought so, any ideas how to fix it? Am i right by saying that its the black box under the dash? Is there way of bypassing it?

[kite]

Sorry, no idea how to fix.
Try resycing your key, there lots of posts on here how to do it.

[bongosworld]

Do those things have a transponder chip in the keys?

[smokey0123]

try starting it with the spare key

[bongosworld]

There is a transponder chip in the key, the key i was using didnt have a chip so i found the orginal and it is now purring like a kitten!
Cheers smokey0123 and kitten!!!

[smokey0123]

pleased you got it sorted :D it may be worth getting another spare key and getting it programmed to the immobiliser so youve always got a backup incase you loose your working 1.