Engine Compression

Disconnect fuel shut-off solenoid wire. Remore injectors. Install Compression Gauge and Adapter (J-35129) into injecxtor hole. Install injector retaining clamps. Crank engine until no further rise in pressure is indicated on gauge.

If piston rings and valves are in good condition, the highest pressure increase will be seen on the 1st full compression stroke. Compression will build up to maximum on subsequent strokes

If compression increases only gradually on each compression stroke, this indicates that burnt valve seats or worn valve guides. If maximum pressure is low on all cylinders, this indicates worn pistons, rings, or valves.