New owner needs a little help

Just picked up my first mk1,it's a 83 Gti cabby.It's going to be my daily driver until summer,by which time my Mk2 Tdi project will hopefully take it's place (however i'm starting to fall for the mk1 so things may change 8)

Anyway,it has a few issues…..

1.Rough idle and slight misfire on steady throttle (fine under load and pulls well).I've rectified the following….

cracked dizzy cap
tracking No.2 HT lead
perished breather hose
loose vacuum pipes
Vacuum pipe disconnected behind dash (onto clocks for economy gauge i think)
Timing waaaay advanced (stuggled to turn over sometimes)


The previous owner had tried to mask all this by increasing the idle to about 1500 rpm :roll:

It's a million times better,but still not perfect and tends to bouce up and down slightly around 900rpm.I can feel it vibrate from inside the car.I've tried tweaking the mixture very slightly one way,then back (about 180 degree turn on allen key in total),and found it's happiest setting,which was half way point,although i hope to get it on an analyser soon.

It starts great from cold,idle comes down nicely when warm,but the miss is still there,any idea what i should check next?

2.Just to clarify,ignition timing marks on the flywheel,i have a slot across the edge which has been marked with white paint,is this tdc or the 6 degree before setting?

3.the digital readout on the dash comes on with ignition,then slowly fades away :?

4.I don't believe the temp gauge as it quickly goes up to about 7/8 and stays there,is this a common fault?


apart from that,it's a great little car!!

1. 180degrees is a huge amount to turn the co screw! deffo get it on a reader.  make sure there are no vac leaks anyware, remove inlet boots and check in all the folds for hidden splits.

2. there are 2 marks, small punch mark which is TDC and a large diamond which is BTDC.
 
I assume this is a 1.8 yes? if so, you set ign timing at idle, line the diamond mark up so it looks like the piccy above, simples.


3. check the earth wires to the head, plus the one between head and coil mounting bolt. brown/whirte wire to head is main earth for dash. if that doesnt help check the dash fuse is ok, could be corroded or something. failing that you may need new dash

4. normal running is at 1/2, 3/4 is when fan should kick in. 7/8 is too high, could be related to dash fault above

Thanks Johnny!

I turned the mixture screw first one way (till the revs dropped),then back again (till revs dropped).This in total was 180 degrees.I then found that it's happiest setting was mid-way between the two,which more or less took me back where i started!.(I will check it on an analyser when i get the chance)

Thanks for the head earth strap tip - i'll have a look at this tomorrow.My car had 3 gauges in the console which were not connected, luckily one of them is water temp.I've now hooked this up and can confirm that the dash gauge is 20 degrees out :roll:

Since soaking the engine bay in a whole tin of WD it's behaving a lot better,i'm very pleased with cold starts now.I just have to sort the bulhead now which is quite badly split by the clutch cable (the damage extends about 8 inches )