Mechanical Inspection: Compression
Check engine mechanical condition with a compression gauge, vacuum gauge, or an engine analyzer. See engine analyzer manual for specific instructions. To check engine compression with a compression gauge, bring engine to normal operating temperature. Disconnect fuel injector connectors. Remove ignition coils. Remove all spark plugs. Fully open throttle. Ensure engine cranking speed is at least 250 RPM when measuring compression. Repeat engine compression test procedure at least 2 times.
COMPRESSION SPECIFICATIONS
| Application | Specification | |
|---|---|---|
| Compression Ratio | 10.5:1 | |
| Compression Pressure | ||
| ES300 | 218 psi (15.3 kg/cm2 ) | |
| GS300 & SC300 | 192 psi (13.5 kg/cm2 ) | |
| GS400, LS400 & SC400 | 178 psi (12.5 kg/cm2 ) | |
| Minimum Compression Pressure | ||
| ES300 | 145 psi (10.2 kg/cm2 ) | |
| GS300 & SC300 | 156 psi (11.0 kg/cm2 ) | |
| GS400, LS400 & SC400 | 142 psi (10.0 kg/cm2 ) | |
| Maximum Variation Between Cylinders | 14 psi (1.0 kg/cm2 ) | |