This is the Bosch 0432131694, a new nozzle and holder assembly for Cummins B-series engines. It replaces Cummins 3932123 and the Cummins service number 3802905. The injector body carries the ID 2123 and the holder is a Bosch KDAL59P6. Catalogs list it for the 4B and 4BT 3.9L four-cylinder and for 5.9L six-cylinder builds that use the same injector. It opens at 240 to 254 bar. It is a Bosch-made part, sold each.

Hard starting, white or black smoke, a rough idle, fuel knock and fuel in the oil are the usual signs of worn nozzles on these engines. Mechanical injectors wear as a set, so most shops test or replace all of them at once. A weak lift pump, air in the supply line or a worn injection pump cause the same complaints, so rule those out first. The 3.9L used several injectors over the years. They look alike and carry different numbers, so match the Cummins number or the body ID on your old injector.

Specifications

Fits / Applications

• Cummins 4B and 4BT 3.9L four-cylinder builds that call for injector 3932123 or service number 3802905
• Cummins 6BT 5.9L six-cylinder builds that call for injector 3932123
• Old injector stamped with body ID 2123
• Four injectors on the 3.9L, six on the 5.9L

Fit a new sealing washer under each injector and make sure the old one is out of the bore. Flush the lines before you connect them, change the fuel filter and bleed the system. Torque the hold-down to the engine manual, not by feel.

Part Numbers & Cross Reference

Bosch 0432131694  ·  Cummins 3932123  ·  Cummins 3802905  ·  Bosch nozzle holder KDAL59P6

Cross-reference numbers can change with engine serial, build year and emissions tier, so treat this list as a starting point. Send us your engine serial number and we will confirm the exact match against your build before anything ships. That check is free and takes a few minutes.

Frequently Asked Questions

What numbers does the Bosch 0432131694 replace?

Cummins 3932123 and the Cummins service number 3802905. The body ID stamped on the injector is 2123.

Is it the same as the 0432131698?

No. Both open at 240 to 254 bar, but the 698 is Cummins 3930573 and Case J930573, on a KDAL59P16 holder with body ID 0573. This one is Cummins 3932123 on a KDAL59P6 holder with body ID 2123. Order by the number on your old injector.

Does it fit the 5.9L as well as the 3.9L?

Catalogs list Cummins 3932123 on both four-cylinder 3.9L and six-cylinder 5.9L builds. Call 530-668-0818 with your engine serial number or CPL and we will confirm it for your engine.

Is it new, and do I send my old injector back?

It is a new Bosch injector, not a rebuild. It is sold outright, so there is no core to return.

Related Parts

• Cummins 4BT 3.9L & 6BT 5.9L Mechanical Fuel Injector (3930131, 3802748) | Bosch 0432131743 New
• Cummins 4BT 3.9L & 6BT 5.9L Mechanical Fuel Injector (3926819, 3802547) | Bosch 0432133861 New
• Cummins 4BT 3.9L & 6BT 5.9L 7 mm Tip Mechanical Fuel Injector (3919302, 3802327) | Bosch 0432131840 New
• Cummins 4BT 3.9L, Case, Kobelco VE4 Injection Pump 0460424081 | Bosch Authorized Remanufactured by VFI
• Bosch P7100 Inline Injection Pump Rebuild Service

Why Buy From Valley Fuel Injection

We are a diesel fuel-injection and turbocharger shop in Woodland, CA, rebuilding pumps, injectors and turbos on our own benches since 1993, not a drop-ship storefront. When you call, you talk to the people who test these units. We verify fitment against your engine serial, VIN or build date before anything ships, so the right part arrives the first time.