1994/07/01 Caterpillar

Fuel Injection Nozzle Spray Orifice Plugging{1254}

Usage:

3406B/C Truck Engines

Some fuel injection nozzles are being found with one or more spray orifices plugged. Some of the symptoms of plugged nozzle orifices are misfire, acceleration flutter, or possibly low power. In some cases, complete sets of nozzles have been changed when only one or two nozzles had plugged orifices.

Testing of returned fuel nozzles indicates that in most cases plugged or partially plugged orifices can be identified by checking the nozzle in a 5P-4150 Nozzle Testing Group and observing the nozzle spray pattern. If any of the above engine symptoms exist and plugged fuel injection nozzle orifices are found with the nozzle test group, only change the plugged nozzles, NOT the complete set of nozzles. The sources of debris that can cause the plugged orifices are being identified and fixes are being made.

Caterpillar Information System:

1994/07/01 Be Sure To Use The Correct Reverse Flow Check Valve{1251}

1994/06/24 Installation Procedure For 1R-0716 Engine Oil Filter{1318}

1994/06/24 Procedure For Lapping Sealing Surfaces Of Fuel Injection Pump Barrels And Bonnets{1251}

1994/06/24 New Valve Lifter Assembly Provide Improved Lubrication Of Lifter Roller And Camshaft Lobes{1209,1210}

1994/06/24 New Rocker Arm Adjustment Screw Used To Adjust Valve Clearance{1123,1100}

1994/06/24 New Intake And Exhaust Valves Used{1105,1100}

1994/05/31 New Oil Cooler And Filter Base Assembly And New Oil Cooler And Filter Base Group Have Stronger Mounting Flanges {1378,1306}

1994/05/31 Date Code On 7000 Series Fuel Injection Nozzles; New Seals Used In 7000 Series Fuel Injection Nozzles {1254}

1994/04/22 Service Tools For Electronic Controls{0781,0782}

1994/04/22 Final Control Group (Personality Module) Update{1902}

1994/04/22 Fuel Injection Pump Improvements{1251}

1994/04/22 Identification Of Intake And Exhaust Valves That May Be Used In Remanufactured Direct Injected 3400 Cylinder Heads{1105}

1994/08/30 Changes To 3116 Truck Engine For 1994{0374}

1994/08/30 Use Of 4C-4377 Stress Plate Group In 3116 Cylinder Block Reconditioning{0672,0673,1201}

1994/08/30 Service Procedure For 40 Pin Connector Seal{1901}

1994/08/30 December 1993 FLASH File Update And Fan Control Logic{1902}

1994/08/30 New 310A Jake Brake® Available{1119}

1994/08/30 New Oil Pressure Regulating Valve Used In Oil Filter Group{1315}

1994/08/30 False Logging Of Diagnostic Codes 100-01 (FC46) "Low Oil Pressure" And 100-11 (FC46) "Very Low Oil Pressure"{1902}

1994/08/30 Longer Studs And Spacers Used To Retain Exhaust Manifolds{1059}

1994/08/30 New Exhaust Manifolds, Longer Mounting Studs And Spacers Used In Exhaust Manifold Groups{1059}

1994/08/30 New Water Seals Used in 3400 Head Assemblies{1124}

1994/08/30 Changing Complete Sets Of Fuel Injection Pump Groups May Not Fix Low Power Problems{1251}

1994/08/30 Use Only Clean Engine Oil To Lubricate Unit Injector O-Rings{1290}