Random misfire - Where to look

[mitnworb]

First of all before I get jumped on, I have searched and read every post I could find about misfires and none of them describe my issue. On my 2006 A4 Quattro 3.2l w/Tiptronic with 83000 miles, I am getting a misfire only on cylinder 4 when I fist step on the gas. I have VCDS and it shows the misfires go away after higher revs. I have installed all new injectors, plugs and coils. I have moved coils and plugs around from different working cylinders and still no change. I have all new upper and lower intake gaskets and seals and I have done the valve cleaning. According to VCDS I get the misfire right at acceleration and every once in a while at idle but not enough to turn on the MIL. Where would be the logical place to start checking to see what could be causing it. Thanks.

[MacFady]

Have you inspected the wiring/coil pack harness to cylinder 4. That's where I'd start given what you describe.

[mitnworb]

I guess that's what you would call it but it only misfires a couple of times. I thougth about maybe switching the harnesses. Is that possible do you know?

[MacFady]

You can swap the harness in its entirety but you can't switch the connectors to different cylinders.

[esandes]

when it comes to misfires i have:
1) changed the original coilpacks to the Bosch. misfire resolved for 6 months. then it came back.
2) upgraded the coilpacks to the R8 version and changed plugs to Bosch copper tri-electrode. it has been working great. the engine is smoother running, better power and mileage.