Hi all, my 3.9v8 serpentine engine is overfueling (plugs black after a short time).Has had new M.A.F., / Stepper motor/ Water temp sensor/ Alternator. Engine ticks over ok, but when try to rev it up ,it wont pick up smoothly. Have had ROVERGUAGE connected and it says no faults. Anyone got any ideas, thanks.
 
Hi all, my 3.9v8 serpentine engine is overfueling (plugs black after a short time).Has had new M.A.F., / Stepper motor/ Water temp sensor/ Alternator. Engine ticks over ok, but when try to rev it up ,it wont pick up smoothly. Have had ROVERGUAGE connected and it says no faults. Anyone got any ideas, thanks.

Could be your fuel pressure regulator gone bad, black plugs poor running and possibly hard to start.
 

Similar threads