its playing up again

[lottysvdub 0]

hi guys need a few more thoughts on my car please :) , my car cut out again on wednesday morning on the way to work and wouldnt start again :x so i got it towed home complments of my wife , anyway i left it untill that night when i got home to have a look at it , had to put a boost pack across the battery as i had flantend it trying to start it earlier , the bloody thing burst in to life much to my supprise anyway it ran ok until you reved it up to around 4000 rpm then it would cough and fart a bit , i left the car until today to have a propper look at it as ive been to busy to before today , with a timming light across the plug leads individualy i can pick up a miss fire at around 4000 rpm and across the king lead its the same , so im thinking plugs leads and a coil to eliminate the fault , should i go to VW this time as i changed most of this last year with stuff from GSF and it seems to be at fault again , also whilest testing everything today my cooling fans didnt cut in at all so i switched them on manualy at 110 c i think its the thermo switch again as well , does any one know the pin numbers in relation to the 3 coloured wires to the switch as i want to know which one goes were as i think it could be wired up wrong via the previous owners attempt at rewiring the switch as before the fans stopped working it only ever worked just before 110c . any suggestions would be appreciated thanks guy oh yes its a 2ltr 16 v :oops: