I had to do a heater matrix change on my 1996 audi 80 cab, also changed the ignition lock and barrel. Both operations were a great success but, as they say, the patient didn't survive. The car starts first time but will only run for a couple of seconds. Auto electrician says it isn't the immobiliser. I can set, trigger and disarm the alarm also open and close locks on after market fob. I have tried the old ignition lock and barrel back in place but same result, anyone any ideas?