UK Car Repair: Engine dies while driving Rover 216sli 1.6 L Reg, clutch pedal, head gasket

Question
I have a Rover 216sli with Honda engine, L Reg 1.6. While driving when you
approach traffic lights and change down and press the clutch the revs drop so
low it sometimes cuts out.  The car starts again after persistent turning over
or leaving it for a few minutes. Sometimes straight away. Its not always like
this some days it will be fine and idle normally.

Ive put new spark plugs in and the battery is in excellent condition, but now
the problem is getting worse, it died on me 3 times in a 5 mile journey last
night. Managed to get it back home though!

Any suggestions would be appreciated, my thoughts is that it may be fuel
related or perhaps the head gasket, but im no expert.  

Answer
This condition is typical of a car that has excess play in the crankshaft. When you push the clutch if forces the crank forward misaligning the con rods and causing it to tighten up. There is no easy answer other than re shiming the crank. When you try to restart the car do NOT hold the clutch pedal down.