I have had the head overhauled, new valves, guides, seats, plugs etc. The carb's were also overhauled completely with all new parts. The work was done by a long time Jaguar mechanic who specializes in SU Carbs.
Since the repair, the car runs fine when at speed but lacks power when cold and backfires when accelerating. Obviously too lean or a timing problem. The shop's gas analyzer says the mixture is OK and timing is set properly but still the acceleration is terrible when engine cold. Much better when at operating temp but still lacking the true acceleration of the car/backfiring. Have tried many things including colder plugs but the problem remains. As a last resort the shop is trying different size needle valves in the carb's. I see the recommended size is .125 for the HD8 SU's. Can anyone suggest some other area to consider?
Glen Read
