- Industrial Engine:
- C4.4 (S/N: 4441-UP)
- Generator Set:
- C4.4 (S/N: D4B1-UP; D4D1-UP)
- Marine Generator Set:
- C6.6 (S/N: C6T1-UP)
- C6.6 (S/N: 6661-UP)
- C6.6 (S/N: SDA1-UP; N6D1-UP; MRW1-UP)
Description of Change: An improved electronic unit injector has been introduced on C6.6 and C4.4 engines. The new electronic unit injector has advanced material technology on the control valve of the electronic unit injector.
Note: If your engine has no issues with performance, then there is no need to replace the electronic unit injectors or the flash files.
Adaptable To:
Note: If there is a problem with a single electronic unit injector, the latest part number for the electronic unit injector should be installed. The part numbers in the same group letter that are shown in table 1 can be interchanged in the same engine.The electronic unit injectors that are installed in the C6.6 and C4.4 engines have been marked with the manufacturers identification number. Refer to table 1 for the correct Caterpillar part number.
Note: A single electronic unit injector that has been damaged may be replaced with the latest electronic unit injector with the same group letter. The electronic unit injectors that have high leakoff will have the same rate of wear. The electronic unit injectors should be replaced as a set. If 276-8280 Fuel Injector Gp is installed in the engine and the 321-1080 Fuel Injector Gp can be installed in order to replace a single damaged 276-8280 Fuel Injector Gp .
Note: The group letters that are listed in the second column of table 1 represent the part number of the succession replacement for a given electronic unit injector. A typical example is the 276-8280 Fuel Injector Gp. This is the first part number that is listed in group "A". The 276-8280 Fuel Injector Gp replacements are 282-0480 Fuel Injector Gp and 293-9580 Fuel Injector Gp. The latest replacement part number of the electronic unit injector is 321-1080 Fuel Injector Gp. All electronic unit injectors that are listed in a group have the same performance characteristics. The materials that are used to manufacture the electronic unit injectors have altered to enhance resistance to damage that is caused by debris.
If there are no electronic unit injector part numbers listed for the latest flash file for your engine arrangement in Technical Marketing Information (TMI) and a replacement electronic unit injector is required, install the electronic unit injectors as directed in this article.
It is important to match the correct injector and the correct flash file. Refer to Troubleshooting, "Flash Programming" for the correct procedure. If you have questions regarding the correct electronic unit injector and the correct flash file for your engine, ask your Technical Communicator to enter a Dealer Solution Network Service Request.
The 321-0990 Fuel Injector Gp is installed to the engines that are shown in table 2. A new set of electronic unit injectors must be installed only if there is high leakoff of the electronic unit injector. Refer to Special Instruction, KENR6938, "High Leakoff of the Electronic Unit Injector" for the correct procedure. It is important to match the correct electronic unit injector and the correct flash file. Failure to match the correct electronic unit injector and the correct flash file may result in engine damage. The engine will not meet emissions.
Note: Refer to illustration 1 for table 2.
| Replacement Electronic Unit Injector | Engine Arrangement |
| 321-0990 | 310-6950 |
| 321-0990 | 274-1174 |
| 321-0990 | 308-5597 |
| 321-0990 | 335-1535 |
| 321-0990 | 310-6948 |
| 321-0990 | 329-3157 |
| 321-0990 | 335-1547 |
| 321-0990 | 284-4621 |
| 321-0990 | 310-6938 |
| 321-0990 | 284-4623 |
| 321-0990 | 274-1178 |
| 321-0990 | 310-6945 |
| 321-0990 | 310-6953 |
| 321-0990 | 310-6932 |
Note: Refer to illustration 1 for table 3.
| Group Letter | Old electronic unit injector | New electronic unit injector |
|---|---|---|
| C | 276-8270 | 320-0670 |
| 282-0470 | ||
| 293-9570 | ||
| 321-1070 | ||
| A | 276-8280 | 320-0680 (1) |
| 282-0480 | ||
| 293-9580 | ||
| 321-1080 | ||
| B | 276-8290 | 320-0690 |
| 282-0490 | ||
| 293-9590 | ||
| 321-0990 | ||
| D | 282-0455 | 320-0655 |
| 293-9555 | ||
| 321-0955 | ||
| 284-4034 |
| ( 1 ) | For group A, a new electronic unit injector is installed in order to improve engine performance on the engines that are listed in table 4. The 321-3600 Fuel Injector Gp is now installed to these engines. A new set of electronic unit injectors must be installed if there is high leakoff of the electronic unit injector. It is important to match the correct injector and the correct flash file. |
 | |
| Illustration 1 | g02151138 |
It is important to match the correct electronic unit injector and the correct flash file.
 | |
| Illustration 2 | g01935915 |
Typical example | |
As a typical example, use engine serial number 66600520. This engine was manufactured with 282-0480 Fuel Injector Gp that has been replaced with 321-1080 Fuel Injector Gp. Enter engine serial number 66600520 in TMI. Select the flash file folder (2) .
The latest flash file for engine serial number 66600520 is 314-6749 Engine Ratings Electronic Software Gp (1). The flash file is compatible with 292-3780 Fuel Injector Gp, 306-9380 Fuel Injector Gp or 320-0690 Fuel Injector Gp. If the original 282-0480 Fuel Injector Gp are still installed in the engine, the 314-6749 Engine Ratings Electronic Software Gp would not be compatible. Install the 320-0690 Fuel Injector Gp in order to be compatible with the 314-6749 Engine Ratings Electronic Software Gp. If the 320-0690 Fuel Injector Gp are installed, the electronic unit injectors must be installed as a completed set. The 320-0690 Fuel Injector Gp cannot be mixed with the 282-0480 Fuel Injector Gp .
Note: If your engine has no issues with performance, then there is no need to replace the electronic unit injectors or the flash files. The replacement of the electronic unit injector and flash file is a complicated procedure. If you have questions regarding the correct electronic unit injector and the correct flash file for your engine, ask your Technical Communicator to enter a Dealer Solution Network Service Request.