0586363 JOHNSON ECU ASSY., 150HP Models

Refer to the Operation and Maintenance Manual , "General Hazard Information and High Pressure Fuel Lines" before adjustments and repairs are performed.Note: Refer to Systems Operation, "Cleanliness of Fuel System Components" for detailed information on the standards of cleanliness that must be observed during ALL work on the fuel system.Ensure that all adjustments and repairs are performed by authorized personnel that have had the correct training.
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
If air enters the fuel system, the air must be purged from the fuel system before the engine can be started. Air can enter the fuel system when the following events occur:
The fuel tank is empty or the fuel tank has been partially drained.
The low-pressure fuel lines are disconnected.
A leak exists in the low-pressure fuel system.
The fuel filter has been replaced.
The engine has not been in use for an extended period.Hand Fuel Priming Pump
DO NOT loosen the high-pressure fuel lines in order to purge air from the fuel system. This procedure is not required.Use the following procedures in order to remove air from the fuel system:
Ensure that the fuel system is in working order to remove air from the fuel system. Ensure that the primary filter is clean and free from dirt.
Check that the fuel supply valve (if equipped) is in the ON position.
Illustration 1 g03352705
Typical example
Unlock priming pump handle (1) by turning handle counterclockwise. Note: During priming the hand pressure required to prime the fuel system will increase.
Operate the hand priming pump for 2 minutes. After 2 minutes, the system should be primed and the engine ready to be started. Lock and priming handle by securing the handle into the body of the pump (2). Push handle in and turn handle clockwise to lock. Note: Ensure priming handle (1) is locked correctly into place . If the priming handle is not locked into place, fuel flow to the fuel system will be obstructed.
Operate the engine starter and crank the engine . After the engine has started, operate the engine at a low idle for a minimum of 5 minutes. Operating the engine at a low idle will help ensure that the air has been removed from the fuel system.
If the engine will not start, repeat steps 2 to step 5. After the engine has stopped, you must wait for 10 minutes in order to allow the fuel pressure to be purged from the high-pressure fuel lines before any service or repair is performed on the engine fuel lines. If necessary, perform minor adjustments. Repair any leaks from the low-pressure fuel system and from the cooling, lubrication, or air systems. Replace any high-pressure fuel line that has leaked. Refer to Disassembly and Assembly, "Fuel Injection Lines - Install".If you inspect the engine in operation, always use the proper inspection procedure in order to avoid a fluid penetration hazard. Refer to Operation and Maintenance Manual, "General hazard Information".
The low-pressure fuel system can be pressurized for a time period after the engine has stopped operating. The operating pressure of the low-pressure fuel system can be 500 kPa (73 psi). The secondary fuel filters should be drained before any maintenance of the low-pressure fuel system is carried out.
If the engine will not start, refer to Troubleshooting, "Engine Cranks but will not Start".Electric Fuel Priming Pump
Do not crank the engine continuously for more than 30 seconds. Allow the starting motor to cool for two minutes before cranking the engine again.
DO NOT loosen the high-pressure fuel lines in order to purge air from the fuel system. This procedure is not required.
Ensure that the fuel system is in working order. Check that the fuel supply valve (if equipped) is in the ON position.
Illustration 2 g03359890
Typical example
Remove the protection cap (1). Depress valve (2) in order to purge air. Caterpillar recommends that a tire inflator with a suitable length of clear hose attached to be used. Refer to illustration 2.
Illustration 3 g02948436
(A) Connection for clear hose
(B) Inflator
With tool (B) installed to valve (2) turn the keyswitch to the ON position. When fuel has filled the bowl at the bottom of the filter (3), the tool (B) can be removed. Ensure that the protection cap (1) is install.
After the keyswitch is turned to the ON position, the relay (4) will allow operation of the electric priming pump for 2 minutes. After 2 minutes, turn the keyswitch in order to operate the starter and crank the engine. If the engine does not start, turn the keyswitch OFF and then ON again and allow 1 minutes 30 seconds before starting the engine.
After the engine has started, operate the engine at a low idle for a minimum of 5 minutes. Operating the engine at a low idle will help ensure that the air has been removed from the fuel system. After the engine has stopped, you must wait for 10 minutes in order to allow the fuel pressure to be purged from the high-pressure fuel lines before any service or repair is performed on the engine fuel lines. If necessary, perform minor adjustments. Repair any leaks from the low-pressure fuel system and from the cooling, lubrication, or air systems. Replace any high-pressure fuel line that has leaked. Refer to Disassembly and Assembly, "Fuel Injection Lines - Install".If you inspect the engine in operation, always use the proper inspection procedure in order to avoid a fluid penetration hazard. Refer to Operation and Maintenance Manual, "General hazard Information".
The low-pressure fuel system can be pressurized for a time period after the engine has stopped operating. The operating pressure of the low-pressure fuel system can be 500 kPa (73 psi). The secondary fuel filters should be drained before any maintenance of the low-pressure fuel system is carried out.
If the engine will not start, refer to Troubleshooting, "Engine Cranks but will not Start".