View Full Version : Rough idle when cold

29-11-2009, 01:31 PM
Hello there I am new here and my name is Cory and I live in Germany. I own a 35I 1992 Passat with a 1.8 (ABS engine code) the problem is: In the morning when I first start the vehicle it runs really rough and wants to die I have to sit there for about 2-3 minutes with my foot on the gas to keep it running, then it runs fine. I have checked the cold start door in the air box and replaced the vacumm diaphram that opens up but still did not fix the problem. Any help would be greatly appreciated.

29-11-2009, 06:20 PM

Could be a problem with the Temperature sender for the ECU? I do not know the ABS engine, but on a PB engine it is fitted to the plastic water pipe on the front of the cylinder head?
A bad Temp sender can cause the ECU to think the engine is warm, so no cold enrichment is used.

01-12-2009, 10:43 PM
Thanks for the quick reply, Last winter I changed the temp sender because it would not start at all until I put a pair of jumper cables on to keep the battery up. Then I changed the sender and everything was fine until about a month ago. Do you think it is going bad again??