Pete, Could you have possibly messed up the timing by moving the ignition distributor when you replaced the cap. Is the rotor down good? Cap must also snap into it's position. Run through the check list. 13 degrees before TDC is the initial setting. Then look while the timing light is hooked up to see if you have advance when you rev up the engine to 2000 rpm, advance should be close to 40 degrees BTDC. See D:04:01. Once you have determined it 's not timing or advance. Then I would look into fuel. Black plugs usually means it's running to rich. I would then think you need to adjust the CO setting. You could also have low pressure on the top of the control plunger which would allow it to rise to high and cause an enrichment problem. Refer to D:02:01 for proper settings of fuel pressure. Be sure to check the 02 sensor, and the frequency valve, If the lambda circuit isn't working properly, the lower chamber of the fuel distributor could be allowing to much fuel to the injectors also. Just a few hints. John Hervey www.specialTauto.com