0433690 JOHNSON CARBURETOR ASSY., Port, 90

Illustration 1 g00934947
Test Step 1. Check for Connector Damage.
Turn the keyswitch to the OFF position.
Thoroughly inspect the ECM connector J1/P1 and the machine connector J2/P2. Inspect all of the other connectors. Refer to the diagnostic functional test Troubleshooting, "Inspecting Electrical Connectors" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the ECM connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the machine connector (allen head screw) for the proper torque of 2.25 0.25 N m (20 2 lb in).
Check the harness and the wiring for abrasion and for pinch points.Expected Result:The connectors and wiring are free of the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - The connectors and wiring are okay. Proceed to Test Step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Stop.Test Step 2. Inspect the Throttle Assembly.Inspect the throttle assembly for damaged components.Expected Result:The throttle assembly operates smoothly without excessive drag. The throttle assembly returns to the low idle position without assistance in less than one second.Results:
OK - The throttle assembly is operating correctly. Proceed to Test Step 3.
Not OK - The throttle assembly is not operating correctly.Repair: Repair the throttle assembly or replace the throttle assembly. The throttle assembly should operate smoothly without excessive drag. The throttle assembly should return to the low idle position without assistance in less than one second. Stop.Test Step 3. Check the Throttle Position with the Caterpillar Electronic Technician (ET).
Connect Cat ET to the cab service tool connector J31. Start Cat ET.
Turn the keyswitch to the ON position. The engine should be off.
Observe the throttle position reading on Cat ET.
Depress the throttle and release the throttle.Expected Result:The throttle position reads 0 percent when the