1985 VW Golf GTi 8v (K-Jet) - Idle pulsating

[Taylo3480]

Hi all,
I recently bought myself a 1985 Golf GTi 8v (K-Jet) however I have noticed that the engine pulsates at idle.  The engine rocks a little but I must add, its not all the time it seems to be an intimitant fault.
Any idea's what this could be...? Anyone else experienced the same kind of thing?
Appreciate the help if possible! 

[SoundillusioN]

It's always a little hard to diagnose issues like this by description.  Would you go as far as saying its misfiring and is it when cold or warmed up or both? Knowing this would be helpful.

Only yesterday mine was being a little like this and it turned out to be loose spark plug. 

[bodga]

Could be a HT lead breaking down, have a look under the bonnet when its dark to see if there are any sparks off the leads. Does it missfire under load? Has it been stood for a while?
If you havent already give it a service, If you dont change the plugs, check them, they should all be the same colour, if one is different, check the lead for arcing, change it if you have a spare.
 

Mine will be a little upset when i tax it april 1st, its been stood in a garage all winter. after a few runs it will be fine. 

[Taylo3480]

Hi all,

It seems to do this when warm now you mention it - It does have new plugs and leads and distributor but I noticed the rotor arm was pitted.  Do you think this would cause this...? Or would it do that once started up anyway?
I will check in the dark to see if its arking out, but the leads were replaced a month before I purchased the car as were the plugs.

[sparkplug]

i have an 1985 8V (K-jet) too 
check your H/T lead that goes up to the ignition coil on the bulkhead
they often manage to chafe through on hose clips and cause a misfire