Engine Compression
To check engine compression, bring engine to normal operating temperature. Disconnect fuel injector connectors. Remove air intake hose from throttle body. Remove ignition coils and high-tension cord set assembly. On all models, remove all spark plugs. Fully open throttle. Ensure engine cranking speed is at least 250 RPM when measuring compression.
COMPRESSION SPECIFICATIONS
| Application | Specification | |
|---|---|---|
| Compression Ratio | 10.5:1 | |
| Compression Pressure | ||
| ES300 | 218 psi (15.3 kg/cm2 ) | |
| GS300 & SC300 | 195 psi (13.5 kg/cm2 ) | |
| GS400, LS400 & SC400 | 178 psi (12.5 kg/cm2 ) | |
| Minimum Compression Pressure | ||
| ES300 | 145 psi (10.1 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 ) | |