My 99 non turbo just started doing this. When I step on the accel, the idle just drops then reacts. If it is at idle it will most likely stall but at higher rpms I will stump the throttle and the rpms drop than goes up. Bad hesitation.

 

For got to mention that there is no check engine light.

 

has the car presented a check engine light yet?

hesitation is caused when the newly injected gas quenches the spark. that can be caused by either a rich mixture or a cold spark. On the mixture side, problems can be caused by vacuum leaks, fuel pressure is off, dirty intake parts (MAF, idle air valve, throttle body). On the spark side, it can be plugs, wires, coils (for the cars with coil packs). I'd start by inspecting the vacuum lines and intake tubing, intake parts etc, then throw in some new plugs and take a close look at the coil pack connectors for cracks etc. You may even want to try popping off the head cover and start up the car in a dark garage to see if you can see any arcing (misting with water can help). If your coils have over 100K on them they may be a cause but usually they will create a CEL code for a misfire on one particular cylinder. Anything change as the engine warms up to suggest a temp sensor?

 

Thanks for the help MT. The CEL has not come on. I just changed the plugs and they where black which I guess means running rich. Is there a vacuum diagram on a non turbo out there. I have checked like crazy but only turbo. You would thing that the CEL would come on if its spark or vacuum. I haven't drive it yet, afraid of getting stuck but will try it now.

 

Just took it out to fill tank and noticed that if I instantly step on the accel at idle, it stalls. Then if I feather the throttle and then floor it takes off. Makes no sence, it seems as long I keep pressure on the throttle it will not hesitate but when I lift off, it stumbles again then takes off. Still no CEL and runs perfect,other than the stumble.

 

I drove the car for 40 miles straight and little by little the hesitation want away. I was happy but puzzled. I get in the car again to go home and I see the CEL on. Check the code and it gives p1008. I clear it and I can hear a change in the tone of the engine and the hesitation came back but this time after 40 miles it didn't go away. WTF

 

Since it's set a P1008 maybe you have a ETM going bad.