Car is a Mk1 Golf Cabriolet with JH1 injected engine.
The car struggles to catch when the engine is warm. It turns over easily but will start to fire on only 1 or 2 cylinders for a while before catching on all 4. When cold, there is no problem - it starts normally. When running, either hot or cold, the car drives normally.
I have replaced the plugs, leads and battery, but no change. I have also replaced the fuel filter, thinking there was a blockage, but again no change.
The distributor cap and rotor seem a little worn and there is carbon deposits that I scrape off sometimes. Could that be a cause?