ellis_in_s4 za rulem

Couple month ago I installed the Bosch Platins, and after I started my car I felt it was idling pretty bad. I drove like this for 3-4 days and I felt power surges in every gear between 2000-4000 rpms. Then I took out the plugs to check the gap (it was fine on all of them) and reinstalled them. The car was running beautifully for a week, and after this the rough idle came back.

I checked Groups 15 and 16 for misfires, and it showed between 6-12 misfires on cylinder 2 once in a while. The strange thing was that the car was idling rough all the time but misfires appeared only once in a while. I put in the stock plugs, same rough idle, swapped the chip to stock, no difference (but misfire readings disappeared).

I was told that it could be a faulty fuel injector, but who knows.
The interesting thing is that when it was 40F outside, it was idling really rough, but when it got to 70-80F it got better (still not the same as before). I made an appointment to the dealer, but since it got warmer and the idle was not as bad, I figured the dealer will tell me their usual thin: "Could not duplicate the problem."

An again, no DTCs all this time.

Any ideas?

LUCIFA

and they tell you "sorry, can't find what the problem was!" "need your signature right here" "thank you, bye bye"

grrr.....

Blitzkrieg

could be temp sensor

aurfalien

could be as simple as plug wire or plug wire connection points

ellis_in_s4 za rulem

Then why it shows no misfires now as well as being temperature sensitive?

aurfalien

... temp sensative and being that your in a truly multi climate area, I would look in replacing the wires (and while your at it, get some nice ones).

I mean what you've described is hard to diagnose so start basic.

Also, a nice thing I keep in mind "when all logic fails, the the illogical is logical" - Spock