A malfunction in either the fuel or ignition system can cause an engine to run rough.
It also can be due to an internal engine condition, such as
1)Bad Valve.
if tappets or valves adjustments are too tight.
2)Bad pistons.
3)primary or secondry circut problem.(for example, ignition coil,ignitor, plug cords, etc.)
4)dirty Fuel filter or choke fuel line.
Make small analysis on to certain conditions;
a)DOES IT OCCUR WHEN IDLING?
B)WHEN ACCELERATING?
C)AT ALL SPEEDS?
Your best bet have a master tecnitian perform diagnostic and tune-up as needed.
Stalling
This can be caused by incorrect idle speed adjustments, a malfunctioning sensor or switch, dirty fuel system parts, worn spark plugs or other engine deficiencies
Does it stall when:
· Hot?
· Cold?
· With air conditioning on?
