Running problems with 82Gti cabby

I am having a problem with the car when it is running and just after starting. When the car starts it idles around 1000 and then after a few seconds it starts to idle erratically dropping down to 4-500 and then back up again to around 850. When you slow down at a junction the revs drop off again quite low but never stalls and when driving the cars seems to hesitate when you accelerate. I have put slick 50 into the petrol and was wondering if this could be causing the problem as it cleans the fuel system, the car has had a new fuel tank and filler neck but not sure about the lines/injectors etc. Thanks in advance for the advice.

what does it idle at when warm?

you want it idling at 850 when warm, once thats set then we can advise you a bit better (thats if it doesnt sort the problem out)   :wink:

The car idles just below 1000 when warm but still drops way down even when the engine is warm especially when changing down at junctions. It still hesitates when its warm as well. Could it be that the timing or idle that needs adjusted and would this sort out the uneven idle when the car first starts as well.

Its probably a little bit too rich.

When you get out of the car after you have been driving it, it does smell of petrol is that what causes this and how do I go about trying to adjust that. Sorry I dont know much about engines or how to work on them. I also forgot to ask about the problem I have starting the car. When the car is warm or cold the first couple of times you turn the key there is only a click and the engine does not turn over, someone told me it is most likely a new starter needed and after a couple of turns of the key it fires ok.

common problem, plenty of causes but, personally i'd check all you vacuum/breather pipes to see if they're all tight, as well as your injector seals (give 'em a lil wiggle) if there's play then they'll need changing

most common cause of idle "hunting" and drop in idle is an air leak somewhere (it wont cost a penny for you to check and it only needs a little leak to cause issues), and there's no point playing around with mixture yourself - without the proper tools you'll just be winging it

check the above, listen out for any hissing/air leaky sounds and hunt them down and try n deal with them, if you still have the problem take it for a tune.. but make sure there's no air leaks otherwise whatever work they do will come to nothing - everything needs to be spot on before hand  :y:  otherwise you'll end up being charged for something you could have done yourself :wink:

forgot to add;

check inside your dizzy cap and rotar arm for wear (pitting and build up around contact surfaces), also the contition of your spark plugs and HT leads

all can leave a smell of unburnt petrol as well as dodgy idle

once all thats elliminated, if the exhaust fumes smell rich (eye watering, quite litterally) then take it for a tune, please dont wing it, its almost an art to get right (along with timing) without the correct tools