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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Compression Check


When checking compression, cylinder pressures should be approximately 427 psi at 200 RPM. Minimum allowable limit is 384 psi at specified cranking speed.
Check compression with engine at normal operating temperature, injection nozzles removed from all cylinders and fuel cut solenoid wiring disconnected.