Unsteady idle

[CHEF_GOLF]

My chim is re making an appreance after storage.
I had this problem before she had a little sleep.
The engine rpm seems to stick for a couple of extra seconds at about 1500-2000rpm then drops.
Or sometimes goes the other way and almost stalls. (Sometimes it has)

Any suggestions. I have cleaned the stepper motor

[StarmistBlue400]

Mine does this all the time. Not sure if its a case of they all do that but it used to rev upto 2000rpm. I cleaned the stepper and it didn't help but unplugging for ECU for 20secs improved it a lot.

[kevin63]

I would start with cleaning the stepper motor out.

[QBee]

And then unplug the ECU for 60 seconds.
Then re-set the base idle, and turn the little adjuster alan key screw for the throttle down to no more than half a turn open.
Then check the throttle position sensor voltage is no more than 0.28 volts when the throttle is closed, adjust it by undoing the two retaining screws and wiggling the sensor ends by the screws up and down until you have the correct voltage.

It is a bit of a case of "they all do that sir. it's a feature", as it is in some circs, like when approaching a roundabout, down to the way the car talks to the ECU to tell it what speed it is going, but you can make it do it as little as possible

[EGB]

kevin63 said:

I would start with cleaning the stepper motor out.

Including the hole the stepper fits into.

[FlipFlopGriff]

Everyone always says stepper, but its highly unlikely to be this. Hundreds of other things it could be though. Likely something simple, just finding it.

FFG

[blitzracing]

Try unplugging the stepper when the car is idling and warm (engine running) and see if the idle becomes stable again.

[CHEF_GOLF]

Fixed it. It was the vacuumed pipe that was blocked. She runs like a dream

[zacherynuk]

CHEF_GOLF said:

Fixed it. It was the vacuumed pipe that was blocked. She runs like a dream

is that the little one that runs up to the window ?

[CHEF_GOLF]

No it was the one that runs to the top of the plenum

[paramount1443]

Mine started to do this too, think it maybe the hot weather. I`m going to well grease the throttle linkage to see if that helps.