Alright so i will try to expain as simply as i can. first off this stuttering happens hot or cold day or night. its almost like i have a fuel injector just randomly shutting off, and i can never make it stutter it just does it when it wants to. It never does it under full throttle and seems to do it more at cruse, or when your not on the gas but not off it (if that makes sense, its that in-between area). I have checked plugs and they are fine...and new ones are in it now, the wires are fine, the cap and rotor are fine. About 6 weeks ago I pulled the injectors and tested the spray on them...they sucked but this stuttering problem just happend so altho the injectors may be all retarded i dont think they have much of a factor on this. Im thinking it could be a faulty ICU or maybe ECU? any ideas would be great since im stumped. thanks!!

 

How's the fuel filter?

 

fuel filter is about 5 months new, but i havent tested fuel pressure to ensure that the injectors have the right pressure behind them...but i would think that would make things really run funny, and only under hard accel.?

 

Check fuel pressure regulator, pull vac line and look for fuel, check for vacuum from throttle body.

when you come off the gas the regulator should direct excess fuel to the return pipe.
If its failing then the injectors are getting too much pressure, they keep firing anyway regardless of the throttle position. The sprak plugs keep sparking when your foot comes off the throttle and the fuel pump keeps delivering fuel, so something has to control the fuel delivery/pressure.

 

So i checked injectors and they wouldnt close when they should haha so new injectors and problem went away and 37mpg came back!!! thanks all