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My car is idling a bit dodgy at the moment, it's at about 950rpm, which is normal idle speed however, is fluctuates slightly and goes down nearly to the point that it stalls, then goes back to normal.

I recently changed the cam belt, but doubt it's that as It's deffo the right tension etc. I also changed the plugs, leads oil and filter. I also replaced both temp sensors and the thermostat.

Any common problems that I should know about? I aint had chance to check the dizzy yet, but I dont think it's gonna be that.

Any help would be cool.

Cheers

does it only do it when it's cold or all the time?

Did you use a genuine blue temp sender ? Does it run rich at the moment ?

It idle's rougher when cold, and actaullt cuts out on some occasions, but when it's warm it's pretty much the same but doesnt cut out.

It's proper annoying me cos it feels like it's gonna cut out all the time and I just want it running smoothly

Dan, the blue temp gauge was from G&S so not VAG, but surely that can't be it. Why would they sell dodgy sensors?

As for running rich, how can I tell? Smoke?

my G40 does something similar, however its only when its been warm, cooled down slightly and then run again.

i've changed the plugs and checked leads, dizzy etc with no problems. changed the blue temp sensor which didn't appear to make a difference, which is annoying!

so i'd be interested in anyone elses thoughts!

regards
Doug

I don't trust non genuine temp sensors, I've had bad ones in the past. For the sake of a few pounds saved, it's more hassle I think.

You can check the resistance of it to see if it's ok. It should be around 200-250 ohms when the engine is hot.

Rich running you would smell and tell by the unusual fuel consumption. That would be a lambda problem fault.

Because I'm a dumb ass, how do I check the ohms?

Fat Ash, seems to think it might be the timing thats out? Would that make it idle low once the engine is warm!?

grab yourself a £5 digital multimeter from aldi's or the like, get the engine warm and switch off, unplug the sensor, turn the meter dial to the 200 or 2000 ohm setting and touch the probes to the sensor pins.... see what the readout says.

I tried advancing the timing last night and it made no difference.

Isn't there a sequence you have to do when adjusting it? i.e. resetting the ECU by unlpuging somat?

Thanks for all your help guy's BTW

Done a fuel filter lately? If not, it's often worth a shot.

If the timing was fine before, then theres no reason it would suddenly be a problem.

You need to set the ignition timing in 'service mode' that involves warming the car up, un plugging the blue temp sender. You should hear the revs rise to about 1200 odd rpm.

If it doesn't do this, it's not going into service mode because either one or more sensor is out or something is miles out of adjustment.

Then you hold the revs at 2000rpm and set the timing to 6 deg +/- 1 degree BTDC.

hi i'm running metz polo gt saloon and i'm having the same problem as you the cars not idling properly and cutting out when cold i changed the oil yesterday and the rocker gasket did you find out what was wrong with your's could you let me know thanks Grant