My 1998 jetta TDI loses power while accelerating and if you lift off the throttle for a second and get back on it it picks back up but will lose power in several seconds. Sometimes it gives a timing control code sometimes nothing. I just resealed the pump off the car put a new timing belt on set the timing with vag - com. I also had the intake off and cleaned the carbon out and replaced the boost hose that goes to the ecm and pressure test to make sure the computer had no internal leak. This thing has me stumped. Any help would be appreciated.