I have a 1998 Chevy Venture minivan with 210,000 miles. For the past seven
month, the van has had a miss or stumble that occurs occasionally. It
seems to happen most while traveling on the interstate as I begin to go up
a grade. The miss happens only one time per hill, it is usually very
strong and harsh. I can sometime cause it to miss if I begin to increase
the speed as if I had encountered a hill. The gas mileage has not
decreased, nor has the power of the motor decreased. No smoke at any time
and the van does not burn oil. Other than this single miss every now and
then, the van runs great.
Things I have replaced or checked:
Spark plugs. (AC/Delco plugs)
Plug wires, twice. Last time with Delco wires.
7X crankshaft position sensor.
Checked the fuel pressure, it is in spec and seems to change pressure
Both oxygen sensors.
Catalytic converter twice, last time with a GM converter.
No codes are stored, the service engine light does not come on. I have an
interface and can connect the OBD II to my laptop, but this does not show
any problem with the various sensors, and the OBD indicates a "pass" on all
Any ideas or help is greatly appreciated,