Compression Check

Minimum compression pressure should be 370 psi for I-Mark and 398 psi for Pickup and Trooper II. Minimum cranking speed should be 200 RPM. Check compression pressure as follows:
1. Start engine and allow to reach normal operating temperature.
2. Remove sensing resistor, glow plug connectors and glow plugs.
3. Disconnect fuel cut solenoid electrical connector.
4. Disconnect quick start system electrical connector located near battery on left side of engine compartment.
5. Connect suitable gauge and adapter, then check compression pressure. If pressure is not as specified, need for engine repair is indicated.