black deposits on rotor arm?

Hi,

its a 3.9 efi v8 from a 96 disco now in my comping truck. I have had sooo many problems with it i don't no were to begin! took the car to a pay and play the other day, it overheated. mind you the engine was not properly timed, although it was there or there about. I put some engine fans on it and changed the thermostat and it now does not overheat (I think!) but it has become a super pig to start. it will crank for 20 seconds easily before any go at any temperature and is really delayed on the throttle. It has had new plugs. In the last 75 miles has had new cap, rotor arm and ht leads. but having alook under the cap today and the cap contacts have white deposits on them and the rotor arm has black deposits. I cleaned these and it started easily. but next attempt it was back to the cranking, low and behold the deposits were back. i do not know what is causing this.

and it drinks fuel like a bitch.

All sounds to me like it might be a timing issue. Have you checked that the vacuum advance is working freely, mechanical advance is operating as it should (not stuck on max advance for instance), checked that the TDC mark is correct etc. The bad starting and delay in the throttle suggests that there might be too much advance at some point to me.

what he said

what they said. get the timing right and theyre lively. they should blip up nicely without any delay.