Engine speed sensor fault!

[merlin's S4]

I've had my car plugged into vagcom to try and diagnose it's running problem and the engine speed sensor came up twice. Now I know this fault will show without the engine running but I had one fault listed for that and another which said something like an intermittant fault with this sensor (sorry can't remember the exact wording). The running problem I would describe as a missfire but the guy with vagcom didn't think it was and said it felt more like an intermittant earth fault as it doesn't happen very often. You can sometimes induce the fault by dropping a gear and flooring it or occasionally with full throttle driving in any gear but it doesn't seem to be limited to those situations. I've replaced the speed sensor which hasn't helped and the problem's really starting to bug me now! Seems like these cars are never quite right! Please help.

Thanks!!

[Knight Rider S4]

Have you went through the usaul check as in coil packs ,spark plugs failing under load,

Mine had a problem were when it was cold it would be fine but the minute it heat up it would miss slightly and i would not get the full power out of the car, the problem ended up been the power out-put stage that fed the 2 coils at the front ,when the car was hot the back plate on it was effected and this caused the problem

If you read the link it goes into great detail of POS and methods of checking for these faults

Hope you find the problem

Cheers
..Steve

http://www.sjmautotechnik.com/trouble_shooting/S4_Ignition.htm

[Mikes2]

Sounds like the timing may be out.

[merlin's S4]

Sounds like the timing may be out.

Not had that suggestion yet! Thanks Mike! How do I go about checking it?

[Mikes2]

The cam pulley and flywheel marks must line up exactly when #1 cyl is at TDC.