i have haltech e6s, when i check the timing with the light the mark is moving all over, what could be the cause?

 

what type pick are you using? stock CAS or S1 or S2 switch? most likely culprit is interference or a loose or poor connection. make sure all ignition connections and all connections in general are soldered and heat shrink wrapped. disconnect the alternator(large source of interference) and route the ignition leads(what type are you using) away from the pick up wiring. and make sure the shielding is grounded on one end of the wire. the E6S does not filter out interference as well as the newer ECU's.

 

thanks, i think it's the way the wire are done.