ABF mk3 16v starting problem

[san]

I have a 97 gti mk3 16v abf, and the car wont start. It fires up but straight away cuts out and then wont start at all. Ive checked spark, fuel pump primes, I just cant figure out what it could be. Would appreciate any help.

[DazVR6]

Crankshaft position sensor.

[ben44]

possible factory imobilizer problem? with the vw immobilizer it will let the car run for three seconds then cut out. try using your spare key!
if not then, crank position sensor or ecu relay............

 

[rubjonny]

yeah sounds exactly like an immobilisor fault, get yourself a vag-com cable and a laptop, no point fubling around in the dark when you can just click a buttoin and have it tell you whats up

[ben44]

no point fubling around in the dark when you can just click a buttoin and have it tell you whats up

if only working women out was this easy!

[somerset_vdub]

 check ur throttle body

  i needed a sensor on mine to ensure it never cutout again.

   it seems to be a big problem and a b!tch to get right

[san]

After cranking the engine for 2 or 3 minutes it eventually started but sounded lumpy and had a misfire. I pressed the accelerator and it just died. It started again eventually and I left it running for a while to warm up and it sounded a lot smoother. Took it for a spin and it seemed to run fine but on gear change the revs stay up for a second.  Also when revving the car on idle the revs seem to go back down slowly. The same starting problem happens when the engine is cold. Ive changed the ecu temp sensor, crank sensor, spark plugs, then I had it plugged into VAGCOM but no faults came up. 

[DazVR6]

After cranking the engine for 2 or 3 minutes it eventually started but sounded lumpy and had a misfire. I pressed the accelerator and it just died. It started again eventually and I left it running for a while to warm up and it sounded a lot smoother. Took it for a spin and it seemed to run fine but on gear change the revs stay up for a second.  Also when revving the car on idle the revs seem to go back down slowly. The same starting problem happens when the engine is cold. Ive changed the ecu temp sensor, crank sensor, spark plugs, then I had it plugged into VAGCOM but no faults came up. 

So have you changed the ecu and fuel pump relays..? if not then they are numbered 30 and 167 and cost about £20 for both from the stealers.

[Pete Taylor]

Check the vac hose that runs from the top corner of the inlet manifold, through the bulkhead to the ECU

[sk8boy73]

had this prob myself.
mine was the brown thiing around the ignition barrel(not sure what its called)
it picks up the signal from the chip in the key.
what i had to do was trace the wire from it to the box just under the dash near the steering column.
you need to move this wire away from all the other wires>
apparently it picks up interfearance from the other wires!
sounds wired but it worked on mine and it has never not started since