Please can anybody help me with the following and suggest what I should check next. I am relatively new to the 7 and techncal knowledge is a bit hit and miss.
My car has a hesitation rather than a misfire. Plugs 1 and 2 come out a bit sooty, 3 comes out looking healthy and 4 wet.
When idling if I remove plug 1 or 2 with insulated pliers the engines slows noticeably. If I remove plug 3 or 4 there is little or no difference to idle. So 3 and 4 dont seem to be doing much.
If I pull the plug leads off with pliers and hold them close to plug there is a healthy spark sound on all 4.
I have replaced plugs, leads, distributor cap and coil pack.
Car is standard 1600 sprint on twin 40's.19,000 miles
Just shanged oil which came out very black (not sure how grey it would look if water mixed in with it) but no evidence of sludge around filler cap or anywhere else.
Any advice would be gratefully received.
Many thanks.
Mark