Quote Originally Posted by a8 tech View Post
I am a fully trained dealer master technician and yes I do
Post a scan
It's likely to be engine speed sender or voltage supply relay to the ecu



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Longtime buddy, can I borrow your experience for a minute please bud.

Friend has a A4 cab B6 2.4, randomly cuts out say could be anything from 5 mins to 25, I've done some checks myself with meter etc.

Lift pump in boot seems perfectly ok, relay which supplies 3 fuse points seems to lose the signal which inturn cuts fuel supply, but even if I force the circuit on the relay to make the pump work, basically push the magnetic connections across with my finger etc, the car still wont start, I can hear the lift pump running, so its not this, I would say ecu or something is stopping the coils from firing it up, there is only 1 wire of the relay that I can possibly fault which goes to the ecu, I'm sure its a number of systems being disabled tbh given diagnosis with fuel pump.

No errors in engine 01 or anyother systems that would affect which lead me to test fuel supply as the issue which usually shows no errors up, so I'm stumped.

Speed sensor maybe one, but this engine isn't something I know tbh, any advice how to diagnose would be great thanks.

TIA.