VALVE-RELIEF 6U1989 - Caterpillar

Caterpillar Products:All 3500B EnginesCaterpillar Products:Machine Engines with Electronic Unit Injectors 3500 SeriesEngine: Commercial with Electronic Unit Injection 3500 SeriesIntroduction
Do not perform any procedure in this Special Instruction until you read this information and you understand this information.This procedure is used when there is a failure of a fuel injector for a 3500 engine and the fuel injector is being returned to Caterpillar for failure analysis. The information for the injector from the field is incomplete many times, or the information for the injector from the field is not provided. Because of the lack of information, determining the root cause for the failure is much more difficult. "No Fault Found" is determined for the injector. This is frustrating for the customer, for the dealer and for Caterpillar. Following the procedures below and accurately documenting the results will provide the failure analysis group with the information that is needed to determine the root cause for the failure of an injector. This should reduce the amount of injectors that are determined "No Fault Found". A copy of the completed worksheet needs to be included in a separate sealed plastic bag with injectors that are being returned for failure analysis.This worksheet is used in conjunction with the troubleshooting steps that are outlined in the literature for the Caterpillar product that is being serviced. Using the Worksheet
Fill out the initial informationThere are five symptoms. Table 3 provides suggestions for the cause and suggestions in order to fix the problem.For example, a customer indicates that an engine is smoking. Refer to Troubleshooting, "Troubleshooting without a Diagnostic Code". After you refer to the Troubleshooting manual, and you still suspect that the fuel injectors are causing the smoke, follow the suggestions that are listed in Table 3.Initial Information
Table 1
Dealer Name     Date    
Dealer Contact Name     RMA Number    
Contact Phone Number     Engine Serial Number    Symptoms
Table 2
Low Power     High Power     Fuel Dilution     Engine Misfire     Smoke    Worksheet
Table 3
Symptom    Check    Reference Information    Results    
Low power
High power
Engine misfire
Smoke     Connect the Caterpillar Electronic Technician (ET)
Refer to Troubleshooting
Ensure to perform engine speed/timing sensor calibration     Use the Cat ET help button with the software, if necessary.
Refer to related information about Cat ET within Troubleshooting     Any problems found?
Yes / No
Explain if Yes    
Low power
High power
Engine misfire
Smoke     Additional Cat ET diagnostic tips can be found in the Service Training Tips Newsletter     Refer to "Service Training Tech Tips Newsletter, No. 27" (1)     Any problems found?
Yes / No
Explain if Yes    
Engine misfire     Does the ECM function properly?
(Solenoids are actuated during the injector solenoid test)     Refer to engine Troubleshooting, "Injector Solenoid Test"     Did each injector solenoid audibly "click?"
Yes / No    
Low power
Engine misfire     Check for a sufficient fuel supply, sufficient fuel transfer pump pressure.
Check manifold (if multiple engines use the same fuel tank)     Use a 1U-5450 Monitor Arrangement to check for adequate fuel flow.     Fuel