erratic idling & bad fuel consumption.... need new air filter element?

[cara_essex]

Hi,

Posted a while back as was having probs with my golf mk3 (R- 1998) cutting out alot, turned out it was the throttle position sensor, so had to fork out for a whole new throttle valve contol unit as you cant just buy the sensor.

It was fitted and car was fine for a few days, original problem disappeared, however its not idling really erratically. Sometimes when I start it first thing in the morning its just vroooooom shoots upto about 2500-3000 revs for a few secs then dies down to normal (however 'normal' is now alot higher than what it used to idle at. Before the new TVCU it used to idle at around 800, now is idling around 1100 all the time, but the main problem now is once the engine warmed up, whenever the cars at a standstill at roundabout etc the revs are constantly up and down between 1100-1800 which is very annoying and also must sound t passers by like I am constantly putting my foot on/off accelarator when Im barely touching it!
As a result the fuel consumption is horrendous!

My question is does this sound like it needs a new air filter element as according to haynes manual these symtons can be that this needs renewing every 20k miles, was last done 20500miles ago!!!

Please help as Im fed up with it its running like **** and sounds like a tank now, am gutted as used to be so quiet and good runner.

thanks, cara x

[Dollso]

check the 3 plugs around the injector unit (one eather side and one at front) also check for air leaks in pipes. sounds more like an electrical fault to me than an air filter. I replaced my TVCU few weeks back, and it idels fine now, although if you were to disconect the plug from the TVCU the car would do excatly what yours is doing now.. my 1st guess would be bad conecton or the unit is faulty (or wrongly fitted) Go on ebay and buy a VAG-COM lead (£15) and goggle "VAG-COM" for the softwear. then run the fault finding program on your car (be carefull thouh, your garage my not have erased the old fault codes since fixing it, so good idea to erase them, drive the car a bit then do the reading - ignore the Hal sendor no sig fault as that always shows up)

[Crasher]

Did you fit a used throttle body or a new unit? The positioner is available separately to the sensor new on the AAM and ABS engines. Have you had it read for fault codes?

[Dollso]

didn't you post about this before? think i remember you saying you paid the guts of £300 to get it sorted.. if so i would be back to whoever did the work and demand they sort it out...