throttle pot collywobbles??

[roger brown]

Help! Have I got the dreaded throttle pot collywobbles? Are these the symptoms? Driving to London in my S2 from Stoke yesterday morning after 11/2 hours steady running the engine started missing, stuttering, picking up, sounding flat like a wet blanket being thumped, more throttle brought no response then in with a bang. Made the Oxford services and called the AA. Change of plugs and all seemed fairly well. Again after about 1 1/2 hours steady running reached the A3 turn off from the M25, off the throttle and the missing begins. Reach the A3 to Kingston and the car is missing and kangerooing. Called the AA again, but scratched heads. By now the car has cooled and I make it to my daughter at Wimbledon. Later set off home with fingers crossed. Again 1 1/2-2 hours in of steady running, decelerate and woops no pick up, just missing, gasping, no throttle response, runs just sounding flat and dead. It's late and I keep going wanting to be home. Ease the throttle a bit and it begins to run better. Decelerate through the M6 roadworks north of B'Ham and it misses and stutters. So it runs better at 80 than at 50! Drive on, feels like the engine mixture is over rich (like a car on full choke when hot), accelerate hard to see if it clears. It does sort of. Enough to get me home. The thing is every time I decelerated the symptoms returned.
Does any of this sound familiar to you? Can you tell where I should begin looking for solutions please? Thanks.

[roger brown]

Thank you to those who have replied. Please keep suggestions coming anyway. I hope to find time at the weekend to try and sort out the problem so any other ideas are most welcome.

[roger brown]

HT leads? Umm, dunno. They're black, fitted with supressors and look pretty ancient. I don't suppose there is a way of checking them on the car is there?