Cold lumpy idle - NOT MAF or LAmbda
 

Ok as title (MY 00 standard uk turbo),

What else could it be? I start the car from work drive about half a mile (Surging) and stop at the traffic ligfhts. It is then lumpy at idle - Stays this way till its warmed up.

I replaced the MAF recently and tested the Lambda tonight - Pin 21 of the ECU blue plug which appeared as expected - i.e. 0 - 0.8 volts up and down.

What else could it be?

Any ideas would be appreciated!!!

Possibly idle control valve if non of the others you mention.

Try a search for "idle", "titles only" and see what problems others have had. Quite a few that will help you.

could it be the water temp sensor ?????
doesnt this give feedback when the engine is cold to feed more fuel, ie 1100 revs cold then settle to 850. If it was playing up giving ecu duff gen, could trick it into raising revs.
What rev range does it rise and fall between ??

The rev range barely moves to be honest - It just judders all the time. Once warm it nearly goes away but not quite - Then judders every 3-4 seconds but only mildly compared to when it is cold.

hmmm try as triple said, idle control valve, give it a clean, be careful to put it back in same position it came out in.

OK will try - Where abouts is it and what do you mean make sure it is put back in the same place. Will give it a try this weekend.

Cheers

As you look at the engine with the bonnet up, its on the engine just to the right of where your intercooler pipe joins the air intake manifold.
You see it is held in place with 2 screws IIRC, if it isnt replaced with same orientation,
it will affect idle speed.

Cleaned the idle control valve this morning and the boost solonoid valve. The idle valve was black and the solonoid valve had some oil in.

Will let you know how I get on with it.

Thanks again.

how did you get on?
 

I have just started my car as normal, warmed up idling from cold as it should.
Had some pratt blocking the road in front of my whilst chatting to his mate on the other side so caned it up the inside and after that the warm idle started pulsing up and down, longer it was left, the wider the surges (900 to 700, then 900 to 500, then 900 to 300 and almost cutting out.

Drives great, just idles in this pulsed manner.

Im going to clean my idle control valve and boost solonoid valve.

Just wandered how you got on with doing yours ?

Was it easy to get to them, remove, clean and replace ??

Thanks,

MKC