paul b
04-08-2008, 07:52 PM
Evening all
I assisted a fellow forum member with his car, a 1999 VW Passat 2.3 VR5.
I've put the car on VAG-COM and there are no faults, so we're struggling a little. :confused:
The problem is, his car has moving flat spots, i.e. if you rev at 2,000rpm and then hit the throttle then the flat spot will come at 3,000rpm. Or if you rev at 3,000rpm and floor it then the flat spot will come at 4,000rpm etc. From the VAG-COM measuring blocks, the ignition timing falls when the flat spot occurs.
It is also starting weird. It starts perfectly, but will then cut out. Re-start and again it's fine, before it cuts out again. This can go on as much as 4 or 5 times I believe. In addition fuel economy is down, though it's never good on a V5. :(
He has changed the MAF (although he has fitted a Bosch pattern one), replaced the coils, spark plugs etc.
Another thing I thought was odd, was that the ignition timing read out fluctuates from BTDC to ATDC in the VAG-COM measuring blocks. Is that meant to happen ?
My theory was if there was a warm up compensator on the B5s. My old Mercedes had a problem like this and it was related to the warm up compensator. Am I right to think the B5s are fitted with a warm up compensator ?
Any help would be greatly appreciated. :beerchug:
Paul
I assisted a fellow forum member with his car, a 1999 VW Passat 2.3 VR5.
I've put the car on VAG-COM and there are no faults, so we're struggling a little. :confused:
The problem is, his car has moving flat spots, i.e. if you rev at 2,000rpm and then hit the throttle then the flat spot will come at 3,000rpm. Or if you rev at 3,000rpm and floor it then the flat spot will come at 4,000rpm etc. From the VAG-COM measuring blocks, the ignition timing falls when the flat spot occurs.
It is also starting weird. It starts perfectly, but will then cut out. Re-start and again it's fine, before it cuts out again. This can go on as much as 4 or 5 times I believe. In addition fuel economy is down, though it's never good on a V5. :(
He has changed the MAF (although he has fitted a Bosch pattern one), replaced the coils, spark plugs etc.
Another thing I thought was odd, was that the ignition timing read out fluctuates from BTDC to ATDC in the VAG-COM measuring blocks. Is that meant to happen ?
My theory was if there was a warm up compensator on the B5s. My old Mercedes had a problem like this and it was related to the warm up compensator. Am I right to think the B5s are fitted with a warm up compensator ?
Any help would be greatly appreciated. :beerchug:
Paul