george

Thank you too all whom have contributed to this thread, I believe that the problem that I had arose from a faulty rotor arm. I have since replaced it and the car now runs well.

Good to know someone else has had a similar problem, I’ll definitely try new leads if the dizzy cap/rotor arm doesn’t change anything.

It’s running a delco 212873r distributor with an AccuSpark electric ignition kit

Thanks for the suggestions, I have ordered a new dizzy cap and have a new spare rotor arm to put on once the new dizzy cap arrives

Hi all first time posting here. I have a Vitesse 6 that runs fine at low RPMs (up to 3.5K) or when cold. Once the car warms up or the revs exceed 3.5k or so the car develops an aggressive misfire/ splutteing and refuses to rev any higher. The misfiring continues to get worse as the car warms up to operating temperature, eventually causing it to stall even under no load at idel. To try and diagnose this issue: I have set the timing at idle with a timing lamp to 10° BTDC. Both the mechanical and vacuum advance work. I’ve also checked the mixture on the carbs (Stromberg 150CD without emission control); with the lifting pin, the revs increase briefly and then go below idle speed, but the misfire still persists. To see if the misfiring was caused by a lean mixture; whilst the car was misfiring I pulled out the choke, but this only made it splutter harder. Checking if the misfiring was caused by a rich mixture I made the mixture intentionally lean but this had no impact on resolving the misfire. I then moved onto the plugs, I found that they were sooty so I cleaned the soot off but the problem still persisted so I retried making the mixture richer or leaner, but had similar results. Thinking the problem was fuel related I took apart the fuel pump to see if the diaphragm or valves were clearly damaged, they weren’t. I have also checked the operation of the fuel pump when hot by lifting the priming lever, but fuel still came out of the pump. I then checked if fuel was getting into the bowls, expecting it to be a vapour lock issue on the carbs I removed the brass mixture adjuster on the bottom, there was plenty of fuel in the bowls, which were also cold. I then wondered if the misfire was caused by some kind of blockage between the fuel tank and pump so I ran the car off a fuel cell that used the cars mechanical fuel pump but the problem still persist. I then wondered if the problem was caused by a head gasket failure (at this point I’m clutching at straws) but there wasn’t any oil in the radiator or water in the oil. At this point I am stumped so would appreciate any help from anyone.