Hi

Apologies if this should be in the RS Turbo section.

Quick over view cars just had new oil pump, rebuilt hybrid turbo, valve stem oil seals, and then set up on a dyno. Car only made 150bhp which is low for the stuff it has fitted and the tuner suggested it might be a tooth out on the timing. Checked the timing and it appeared one tooth out so adjusted it and took it for a run out, it drove really well then all of a sudden it seemed to drop a cylinder. Done the usual checks then attatched a timing gun across all 4 leads, no flash on cylinder 2! So iv changed the plugs, leads, cap, arm and coil, still very intermittent to no flashing on number 2s lead, pull the lead and theres no change to the running of the car. The plug sparks out of the head, iv closed the gap to maybe 5 thou incase it wasnt sparking under compression, still runs as if its a cylinder off. Checked the injector on that cylinder and its fuelling fine, compression checked all 4 pots and they are decent 130-160 cylinder 2 being one of the better ones. Im absolutley stumped, its just appears to not be sparking on 2 when inside the head. Anyone help or experienced this before?

much appreciated

Lee