Anyone Recommend Someone to Tune GTI Bristol/Chippenham area

Hi All,

I've spent a couple of evenings trying to get my GTI running right (it never has since I bought it) but seem to be failing.  I've basically given it a service, new plugs, leads, cap, oil, filters and played around with the mixture (allen key in top of airfilter bit) and retarding/advancing the timing.  I don't seem to be able to get it right, it tends to either be good high up in the rev range but lumpy low down or the other way round. Not sure if there are any other adjustments I'm missing  and I've got to the point where I'd rather just pop it into someone who knows what they are doing with these engines and can get it sweet.  The engine has been rebuilt by TSR around 1997 and is a 1900cc so my first thought was to give it back to them to sort it but wondering if anyone knows anywhere in Bristol (where I work) or Chippenham area (where I live) that they would recommend.

Cheers
 

Are you using super unleaded petrol or normal unleaded?

mark1gls said

Are you using super unleaded petrol or normal unleaded?

Just running normal unleaded 

Try using super unleaded as these cars was set up to run on 98 RON petrol so try some petrol near that sort of figure as normal unleaded is 95 RON. You may need to re adjust the timing as you have to retard it 6 degrees to run normal unleaded.
Keep advancing the timing till the car "pinks" under load then retard it a little till it stops "pinking"  but make a mark some how on the dissy shaft so you know how much you advanced the timing so you can always put it back to how it is now if you wish.

Once the timing is right, may take a few trips to listen out for any "pinking" it may be worth checking the CO2, 1.5 to 2% is what you are looking for.

I tried normal unleaded for about a year but I could not get my car to run right as it felt like it was down on power and I could not get it to idle nice and smooth and I seemed to be using more petrol as I felt I had the press the pedal a little more to get going so I switched back to super unleaded and much happier.

Thanks for taking time to respond, I'll give that a go at the weekend.. a good excuse for a blast into work tomorrow to get rid of the standard unleaded

It definetely smells rich and I really stuggle to get the tic over below about 1200+ revs when it's running at it's best through the rev range and thats with the stop and cable backed right off.. not sure where I can get access to a co2 tester which would be useful.

 

Do you have a friendly local garage or perhaps a regular garage you use for MOT etc which you can ask them to plug into there machine and check for some beer money?

To adjust the idle tick over there is a screw at the back of the throttle body, you need a 7mm spanner to adjust it, you can see the brass coloured screw in the picture.
Don't mess with the screw near the stop which the cable fixes to as that will just move the position of the butterfly valves inside the throttle body.


The rubber oring on the idle screw can also go flat and hard letting in air so may be worth checking that.
Old o ring on idle screw.


New o ring, a little smear of grease helps slide it on.

I've got a mate that restores MK1 GTIs as a hobby and has a garage in Thornbury and lives in Malmesbury. He does my 89' cab and really knows his stuff. PM me for details.