Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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Ignition Timing: Adjustments

Electronic ignition engine timing is entirely controlled by the Powertrain Control Module (PCM). Electronic ignition engine timing is NOT adjustable. Do not attempt to check base timing. You will receive false readings. Base ignition timing is referenced to the position of the crankshaft position sensor. It is set at 10 ± 2 degrees Before Top Dead Center (BTDC).