Hi guys, I've been having a problem with intermittent starting failure and misfiring at low revs - so I've started a little troubleshooting and the plugs looks a bit worse for wear.

I've changed them all this morning, andfound that I simply cannot get the furthest left HT lead (the longest one)back on the plug. When I checked them yesterday I had the same bother, but it went on eventually. However today... If I take the plug out, it's no bother. Put it in, attempt to put the lead on and it just will not go!

Has anyone come across this before? What the heck could be stopping it fitting back? It's driving me mad!

check your old plugs, do they all have the little female screw on them? one could be stuck in the ht lead..

The contacts inside the cap are only thin strips of metal and can get damaged/distorted.

Have a look in the offending cap to see if the contacts have bent out of shape (compare with another one if need be).