I have a Y17DT, 96k in an astravan.
The engine seems to miss a beat, wether i would call it a misfire or a hesitate i dont know, at around 3500RPM. The effect is noticable when driving but does not appear to affect acceleration much.
It appears to happen when the engine is loaded and around max torque in the rev-range., i.e Up a hill in 4th at 3-3.5K RPM is most noticable.
However the problem is not repeatable for the same rpm, and sometimes happens at 2 or 3 points throughout the rev range.
The van is'nt getting much use lately, and i suspect this may have contributed or caused the problem.
My initial guess is a blocked injector or something up with the injector system, has anyone any previous experience with a problem like this?
Any help is greatly appreciated.