I don't know what on earth is going on here... I've had the wagon up on stands for the last week or two while working on the brakes - which ended up being a full overhaul, front calipers and discs all off. At the same time I fitted an anti-lift kit and replaced a missing turbo-downpipe nut.

So I let it back down onto the ground, started it up and immediately it started idling at 2000rpm! Then after a couple of seconds it dropped down to around 1500rpm, then back up to 2000, and it's basically been doing that every time I start it up, bouncing up and down from 1500-2000 in absolute regular time, somewhere between once or twice a second.

Looking at my Power FC trace on all 8 channels I can see every line bouncing up and down perfectly in time with the weird idling. All the sensor voltages that I can see on the commander look OK. At least the ones I know about - throttle position, O2, etc.

So what's going on??? Have I accidentally loosened an electrical plug somewhere while working on the brakes and suspension? Or while I had my arm up next to the downpipe to put the nut on the turbo? Has the heavy whacking with a club hammer (torqueing up the ALK nuts, knocking out brake bolts etc) set off some kind of failsafe? Has the angle of the car when bringing it down off the ramps, activated some kind of weird tilt switch? HELP!!!

 

Not to worry...it's all sorted itself out now! I decided to take it out for a drive anyway, to see what would happen, and before I'd left my front yard the revs had dropped right down to normal. After a minute or so of hunting around between 600 and 1000 revs, it then sorted itself out properly and it's still idling fine now. Weird. Could it have been the Power FC getting its bearings again after a couple of weeks of not having the engine started?