nobody on the VW forums seems to know much... I'm having intermittent rough idling and loss of power. here's the brief..

01 Jetta MKIV, 2.0 engine

started happening suddenly while driving one day

rough idle to the point of flashing CEL and stall, worked fine above 1000rpm

cleaned MAF and it went away, then came back the next day

cleaned MAF and it went away, then came back the next day

replaced MAF and its now running for a few days in a row, but it still shudders and starts misfiring once in a while at idle.

Its the intermittent nature of this that bugs me... My next step is to monkey with the wiring while its running.. see if I can break something that's starting to fail. Any good advice or wild suppositions out there? I'll take anything

 

Does the ecu throw an emissions code? Could be your o2 sensor(s).

 

that's another weird thing. it doesn't throw anything but the misfiring codes.

 

hrmm.. .interesting.

(merged posts)

did you get it sorted?

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woah... this was posted in june. sorry!

 

don't worry, still around and it was quite the 'interesting' problem.

Turns out the MAF and the coil pack went out at the same time so spraying the coil pack with silicone was only a good test after I had replaced the faulty MAF. The coil pack gave me the variability of symptoms based on how much moisture was in the air.

I figured that all out and sold that car ASAP! (full disclosure, I'm not an a$$hat)

With all the stupid trouble that car gave me I'll never mess with a VW again. Damn Germans!