On 4.3 litre engines it may be necessary to remove the distributor and elongate the hold down bolt hole to allow for adjustment. The hold down is fixed to the distributor. In many cases the adjustment is wrong from factory.
Inspection 1. With ignition off, connect scan tool to Data Link Connector (DLC). Start engine and allow it to reach normal operating temperature. 2. Increase engine speed to more than 1000 RPM. Using scan tool, monitor CAM RETARD OFFSET. If camshaft retard indicates zero degrees plus or minus 2 degrees, distributor is properly adjusted. Procedure is complete. If camshaft retard is not zero degrees plus or minus 2 degrees, see ADJUSTMENT. Adjustment 1. Turn ignition off. Slightly loosen distributor hold-down bolt. Start engine. Increase engine speed to more than 1000 RPM. 2. Using scan tool, monitor CAM RETARD OFFSET. To adjust for a negative reading, rotate distributor counterclockwise. To adjust for a positive reading, rotate distributor clockwise. 3. Continue to adjust as necessary until zero degrees plus or minus 2 degrees is attained. Turn ignition off. Tighten distributor hold-down bolt to 25 ft. Lbs. (34 N.M). Start engine. Increase engine speed to more than 1000 RPM. Using scan tool, verify camshaft retard offset adjustment. NOTE: Camshaft retard offset reading will not be accurate with engine speed less than 1000 RPM. Page 1 of 1 3/22/2010 .
Monday, March 22nd, 2010 AT 2:40 PM