hello,i looking for some addvice and possibley a sulution to a problem with my disco, iv had fited a new tank lifter sender unit, a new lift pump, a injection pump, new seals on the sedimenter, all the fuel lines presure tested(all ok)new timing belt, and the disco is still losing power, it dips out then comes back ad if you rev it to 3000 rpm it go up then flucktuates down to just under 3000 rpm then comes back up and there's a bit of grayish smoke comes from the back, and when i drive it dips out on power then comes back and takes a while to get to the speed you want, any sugestions to wat it mite be please
