[MatthewL]

My 1995 420GSI Tourer is showing a high tickover and is a little rough idling, and I think makes a ticking noise under acceleration I don’t think it should. Have completed a few sensor replacements so there are no errors on my P-scan. The tickover when warm is around 950 and I’m worried my throttle stepper isn’t moving as much as it should. I’m loathed to adjust the stopper screw as I suspect this has never been adjusted and the issue is elsewhere. Throttle position sensor seems to get as low as 45. Idle dead band (HotDB Position) is 40. I’ve done the TPS reset a few times.

Can be anyone tell me what these figures should be for a healthy car? Does anything else look wrong to anyone? I’ll upload a picture of the PScan screen shortly. Cheers. Matthew

[MatthewL]

[220 GSi turbo]

The ticking under acceleration could be a manifold gasket starting to leak (which could cause an error in the Lambda sensor signal) or the manifold to downpipe joint starting to leak.

[MatthewL]

Thanks - that’s well worth a look. Is it easy to get a replacement manifold gasket? Might search Rimmers.

[MatthewL]

Found one on eBay will let you know how I get on - thanks mate.

[MatthewL]

Anyone any more thoughts on:
A) What the stepper settings should be for a warm car
B) Whether a load of vibration at around 70 (3500 revs roughly) is normal for a 420?

[Mikey216]

Stepper motor steps should be around 35 with a warm engine.
Mike

[MatthewL]

Thanks Mike. It never got that low so I wonder if it’s tried but is not freed up enough to get there, or if something is telling it to settle higher like a sensor reading. I’ll try squirting oil up the tiny bellows to see if it frees it up at all. It’s definitely still ticking over too high but maybe only by 100 revs. Does still feel a bit shaky on tickover but could that just be eirmbengine mounts?