I recently purchased a TTA and I am trying to figure out a part throttle miss/buck condition. The problem seems worse when cold then improves as engine reaches normal operating temp. I have replaced plugs,wires,coil,module,tps and iat. Fuel pressure does not drop when miss occurs.The computer has no stored trouble codes and both stock and performance chips have been tried. The miss dissappears if I let off the throttle just a bit or if boost starts to build. Also, the air/fuel meter indicates lean simultaneously with each miss. Any suggestions anyone? I would like to figure this problem out before doing any modifications. THANKS!!
Sounds like what I just went through. First replace the coolant temp sensor at the front of the intake manifold. This helped some of my missing when cold, but did not eliminate the part throttle miss/buck (I tried all the stuff you did as well).
Unplug the cam position sensor while the car is warmed up and running. The car will run, but not start with this unplugged. See if that clears things up. If so, pull the CPS and see if there is any crap inside there. Mine was full of dust. I cleaned things up and replaced the sensor (just the cap part) and my miss went away. I'm not sure if the sensor was bad or if the dust inside was causing the problems.
Good Luck,
Kenny Brown
Thanks for the suggestions Kenny. Your suggestions sound logical. I'll try them as soon as possible and keep you posted. This problem seems to be getting worse and I am anxious to start upgrading parts, so I hope this helps. THANKS AGAIN, PETE