ive been having problems with my truck not starting then as soon as i put in gear it dies so i have put a new coil a new thermostat and distributor cap and rotar button on it along with a new battery and now the thing will not start all together its got fire just not starting my fuel pump is kicking on and my filter is flowin it had a crappy little battery that kept getting drained so changed it now it wont start so is it a sensor or a vaccum leak or alternator