Single Fuel Injector for Cummins 4BT / 6BT 3.9L Engines

Replace a single failed injector and restore proper fuel delivery to your Cummins-powered equipment. This OEM-replacement fuel injector is precision-matched to Cummins factory specifications for the 4BT and 6BT engine families — delivering consistent fuel atomization, smooth idle, and reliable engine performance with no modifications required.

✅ What's Included

• 1 × Fuel Injector
• Part Number: 3909475

🔧 Compatible With

• Cummins Engines: 4BT, 6BT, 3.9L
• Fits a wide range of equipment powered by the Cummins B-series engine family, including excavators, skid steers, tractors, generators, marine vessels, and light commercial trucks

⚙️ Key Features

• Direct OEM replacement — plug-and-play fitment, no modifications required
• Precision-calibrated nozzle for consistent fuel atomization
• Restores fuel efficiency, power output, and smooth idle
• Eliminates hard starting, misfires, and excessive exhaust smoke
• Built to withstand the high-pressure demands of heavy-duty diesel operation
• Manufactured to meet or exceed original Cummins specifications

💡 Need a Full Set?

For complete engine balance and maximum uptime, consider our 4-Pack Set — replacing all injectors at once ensures uniform fuel delivery across all cylinders and reduces future labor costs. View the 4-Pack →

🛠️ Signs Your Injector Needs Replacing

• Hard starting or extended crank time
• Rough idle or engine surging under load
• Black or white exhaust smoke
• Loss of power or reduced performance
• Increased fuel consumption
• Diagnostic fault codes related to fuel delivery

SKU: 3909475  |  Fits: Cummins 4BT / 6BT / 3.9L  |  Qty: 1 Injector per Order