1. Verify that TDC mark on dampner is correct by CAREFULLY AND SAFELY rocking engine back and forth with a length of wire in #1 spark plug hole to determine maximum rise of piston. This is TDC. 2. If the dampner mark is correct, disconnect the 4 wire plug near the distributer and start the engine and reset timing with a timing light to factory specs.. Shut engine off and reconnect 4 wire plug. If this does not solve the problem, check the operation of the ESC. While someone watches the timing mark with a timing light, CAREFULLY AND SAFELY tap the engine block on the lower right side, near the knock sensor with a wrench. The timing should retard significantly. (The KNOCK SENSOR is the goofy looking thing screwed into the right bank water drain plug hole.) If this works, some other thoughts are: 3. A clogged or inoperative EGR system will cause more detonation, because the addition of recirculated exhaust lessons the potential of the charge to detonate. 4. A blown head gasket between two cylinders can cause the !@#$%^!@@#$# knock you've ever heard because the leakage between cylinders can cause the neighboring cylinder to light off at the wrong time. Do a compression check and look for cylinders next to each other that show low compression. 5. Contrary to some peoples' opinions, rotating the distributer in a computer controlled engine such as this WILL change the timing, and should lessen or increase the knock. The computer can screw with the timging just so many degrees off the base timing, and when you change the base timing, the range the computer changes the timing will change along with the position of the distributer. Let us know what you find out... IT SHOULD BE INTERESTING!
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