tad said:
The car runs smoothly up to about 3000 rpm, then acts like it has water in the fuel...coughs,misses and backfires, till about 3800 rpm and it smooths out again.
- so below 3000 it's ok, and above 3800 it's OK?
- Is this under gradual / constant throttle?
- Stock SU H6 carbs? DGV weber? DCOE?
- Is this a sudden thing? Had it been running well prior to a recent tank of gas or work done?
Sounds weeeeeird, especially if it's stock SU carbs.... If it's webers I'd say something is amuck (pun intended) in the transistion circuit ("idle" jets)
I would definitely pursue TR3driver's advise - but my gut is saying ignition wouldn't be the culprit if all is well over 3800 RPM.....
With sincere sympathies to your misfortune, this will be an interesting thread to watch. Keep us posted!