Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
have you double checked the timing marks on the timing chain?
BASE TIMINGThe distributor ignition system has no provision for timing adjustment. The base timing is preset when the engine is manufactured and no adjustment is possible.The distributor may need adjusting to prevent crossfire.Refer to Camshaft Retard Offset Adjustment See: Camshaft Retard Offset AdjustmentIgnition timing can only be changed by reprogramming the PCM using Techline Information System 2000 (TIS 2000) PC, and the Tech 2 scan tool. Please contact your dealer for necessary updates and procedures.
Camshaft Retard Offset AdjustmentCamshaft Retard Offset TestThe ignition timing cannot be adjusted. The distributor may need adjusting to prevent crossfire. To insure proper alignment of the distributor, perform the following:
Important: Cam Retard Offset reading will not be accurate below 1,000 RPM.
Adjusting Camshaft Retard Offset
4.1. To compensate for a negative reading, rotate the distributor in the counterclockwise direction.4.2. To compensate for a positive reading, rotate the distributor in the clockwise direction.
then your off a tooth pull the timing cover
i have not but 454 s are not that common at the dealership any more