About a year ago I posted a link in here (technical Q & A) and was looking for help with my Sierra cosworth.
The responce I got was great and I did try all of the suggestions (not cheap I can tell you).
And when I was just about to give up on the car a friend of mine asked to take one last
look at the car before I sold it off, and I let him. Two days later he calls me and asks me to come and try the car and tell him if it was better.
I took the car for a drive and what do you know... The car was absolutely brilliant.
I went back to the garage where he was and asked him what he did to the car.
He said it was pretty simple, the Timing belt was off by one "tooth" (is that what u call it??? )
and the timing gears at the cam shafts were the wrong way around.

Just thought I might share it with you if someone might have the same problem later on.

Same day I broke one of my alloys into pieces (literally) and the great thing about it was I didnt hit anything,
It just gave up