Inconsistant Ability to Idle!!? 1.6 EG GTi

Hi All,

Currently trying to get to the bottom of an idling issue of with my 1600 GTi which has been annoying me for a whie now. Basically what happens is, the car just won't always idle correct.

Sometimes it will idle perfectly at 900rpm. Then you'll drive for say 5-10 mins, and when you come to rest, it will try and idle at 400-500, trying to stall. Other times, it will try and idle at 1400rpm!! This is regardless of the electrical load (headlights, heater) and whether the engine is hot/cold. It almost seems random?

In the last couple of months, I've replaced spark plugs, leads, distributor cap, rotor arm, air filter, all vacuum hoses and checked the timing. The car pulls amazingly well in every gear from idle to the limiter, and even recorded 120mph on the dials (private test track), so no lack of fuel/power. Even checked the fuelling on a wide band lambda which is showing 14.5:1 at idle, which i think is about spot on.

Any ideas on most likely cause? Am I right in thinking the only real things left to change are the Warm Up Regulator and test the Auxillary Air Valve?

Any ideas much appreciate, stalling at junctions is really annoying me now! Cheers

Matt

Try clamping the hose from the AAV back to the manifold.  Just a basic check but if the revs drop then it's not properly closing, although this would mean that your idle is set at it's lowest of 500RPM.  Sounds unlikely to be this.
A fuel problem i would think.  I guess eliminating the WUR might be the first step.
Out of interest (i'm having problems of my own) what does yours idle at when first started cold?

Cheers

Rik

Try clamping the hose from the AAV back to the manifold.  Just a basic check but if the revs drop then it's not properly closing, although this would mean that your idle is set at it's lowest of 500RPM.  Sounds unlikely to be this.
A fuel problem i would think.  I guess eliminating the WUR might be the first step.
Out of interest (i'm having problems of my own) what does yours idle at when first started cold?

Cheers

Rik

Just to update, I removed the WUR today and on inspection of the inlet, I noticed that there were 3 small circular gauze filter type inside. There was also small fragments of crap, which I believe are probably from when the filler neck rusted away years ago. I've cleared it all out, but in doing so, the gauze filters came too - they were wrecked. I put it all back together, minus the gauze filters, and I think I might have sorted my problem although i'm yet to do a proper test drive.

Anyone know whether there should be 3 gauze filters? Or if they have come from else where? Should I be worried?? lol