3512B Generator Set Engines with Dynamic Gas Blending Caterpillar

Engine Top Speed Is Not Obtained

Usage:

Use this procedure to troubleshoot an engine that will not obtain top speed.

Note: If this fault occurs only under load, refer to Troubleshooting, "Acceleration Is Poor or Throttle Response Is Poor".

Probable Causes

Engine misfires, runs rough, or is unstable
Parameters
Software
Input signal
Fuel system
Inlet air restriction
Fuel injectors
Turbocharger
Exhaust restriction
Driven equipment

Recommended Actions

Show/hide table

Table 1
Troubleshooting Test Steps	Values	Results
1. Check the Operation of the Engine	Engine Operation	Result: The engine operation is in a lug condition, is producing excessive smoke, runs rough, or unstable. Proceed to Test Step 5. Result: The engine operation is smooth and appears normal except for top engine speed not being obtained. Proceed to Test Step 2.
2. Check for Incorrect Configuration Parameters A. Connect Cat^® Electronic Technician (ET) to the service tool connector. B. Use Cat ET to verify that the correct parameters are being used. - "High Idle Speed"	Parameters	Result: The parameters are correct. Proceed to Test Step 3. Result: The parameters are not correct. Repair: Input the correct parameters. Refer to Troubleshooting, "Configuration Parameters" for additional information. If the problem is not resolved, proceed to Test Step 3.
3. Ensure that the latest Flash File Software is Installed in the ECM A. Connect Cat ET. B. Use Cat ET to verify that the correct flash file is being used.	Flash File	Result: The latest flash file is installed. Proceed to Test Step 4. Result: The latest flash file is not installed. Repair: Perform the following procedure: 1. Download the latest flash file from SIS web. 2. Install the software into the ECM. Refer to Troubleshooting, "ECM Software - Install" for additional information. If the problem is not resolved, proceed to Test Step 4.
4. Check the Desired Speed Input Signal A. Connect Cat ET. B. Use Cat ET to monitor the following: - "Desired Engine Speed" - "Engine Speed"	Input Signal	Result: The "Desired Engine Speed" parameter is equal to the required engine speed needed for normal operation. The "Engine Speed" parameter is less than "Desired Engine Speed". There is not a problem with the speed signal input. A mechanical problem is not allowing full engine speed to be achieved. Proceed to Test Step 5. Result: The "Desired Engine Speed" parameter is less than the required engine speed needed for normal operation. The "Engine Speed" parameter is equal to "Desired Engine Speed". Repair: There is a problem with the "Desired Engine Speed" input signal to the ECM. Check the device supplying the "Desired Engine Speed" input signal or wiring for proper set-up and connections. If the problem is not resolved, proceed to Test Step 5.
5. Inspect the Fuel System Refer to Testing and Adjusting, "Fuel System Inspection" for additional information. A. Visually check the fuel level in the fuel tank. Do not rely on the fuel gauge only. B. Ensure that the vent in the fuel cap is not filled with debris. C. Ensure that the fuel supply valve (if equipped) is in the full OPEN position. Note: Cold weather adversely affects the characteristics of the fuel. Refer to the engines Operation and Maintenance Manual for information on improving the characteristics of the fuel during cold-weather operation. D. Check fuel quality. Refer to Testing and Adjusting, "Fuel Quality - Test" for additional information. Check the fuel tank for debris or foreign objects which may block the fuel supply. E. Check for fuel leaks.	Fuel System	Result: The fuel system is OK. Proceed to Test Step 6. Result: The fuel system is NOT OK. Repair: Repair or replace damaged fuel system components. If the problem is not resolved, proceed to Test Step 6.
6. Check for a Restriction in the Inlet Air System A. Check the air filter restriction indicator, if equipped. Refer to the Operation and Maintenance Manual for additional information. B. Measure the inlet air restriction for each turbocharger. Refer to Troubleshooting, "Inlet Air Is Restricted" for additional information.	Restriction	Result: The inlet air restriction is OK. Proceed to Test Step 7. Result: The inlet air restriction is NOT OK. An imbalance in the system is discovered. Repair: Repair or replace damaged inlet air system components. Equalize the inlet air restriction for each of the turbochargers. If the problem is not resolved, proceed to Test Step 7.
7. Test the Fuel Injectors A. Connect Cat ET. B. Use Cat ET to perform the following fuel injector tests: - "Injector Solenoid Test" - "Cylinder Cutout Test" Refer to Troubleshooting, "Cat ET Service Features" for additional information.	Fuel Injectors	Result: The tests were not successful. Proceed to Test Step 8. Result: The tests were not successful. Repair: Diagnose the problem. Repair or replace damaged components. If the problem is not resolved, proceed to Test Step 8.
8. Check for Proper Operation of the Turbocharger A. Check for any oil that may be leaking into the inlet air.	Turbocharger	Result: The turbocharger is not leaking oil into the inlet air. Proceed to Test Step 9. Result: The turbocharger is leaking oil into the inlet air. Repair: Repair or replace damaged turbocharger. If the problem is not resolved, proceed to Test Step 9.
9. Check for a Restriction in the Exhaust System Note: A restriction of the exhaust can cause high cylinder temperatures. A. Measure the exhaust restriction during engine operation with a load. For data that is specific to your engine, refer to the Technical Marketing Information (TMI).	Restriction	Result: The exhaust restriction measurement is OK. Proceed to Test Step 10. Result: The exhaust restriction measurement is NOT OK. Repair: Repair or replace damaged exhaust system components. If the problem is not resolved, proceed to Test Step 10.
10. Inspect the Driven Equipment	Driven Equipment	Result: The driven equipment is NOT OK. Repair: Repair or replace damaged driven equipment. Verify that the repair eliminated the problem.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).