Hi all:
VW New Beetle, 2001 1.8T, manual.
I have a rough idle for about 20-30 seconds cold. It often sounds like a consistent one cylinder miss with an intermittent rolling miss. I have the Ross Tech VAG 1551/1552 and pull the random misfire code (16684) and 16687, 16685 & 16686 individual cyl misfire codes. Although I have ocassionally seen these codes before, there were no drivability problems. This current situation started the other day with a bad #3 coil over pack that failed creating real drivability problems; I traced back all wiring into the harness repairing any broken insulation (numerous), confirmed voltages on all coilover pack connectors and pulse from the ECU, replaced plugs and the #3 coil (confirmed bad). All of the problem was resolved except a cold start miss (never happened before). After the initial warm up period, 20-30 seconds, the car runs perfectly in all driving conditions and throws no codes. My O2 sensors are reading fine but I'm always suspicious of sensors over 80K mi (car has 98K). I hear no vacuum leaks and all hoses seem fine. Any ideas anyone?
Thanks in advance for your help!
Uppi
