Buy 3934703 - Genuine Cummins Fuel Control Housing - wisentpartscenter.com

Description

Cummins 3934703 Fuel Control Housing - Genuine Cummins Fuel Control Housing for C8.3 Natural Gas (CNG) Engines

The Cummins 3934703 is the fuel control housing off the C8.3 natural gas (C Gas Plus / CNG) engine. It's the cast body that the gas fuel control components mount to - it carries the fuel passages, the mounting faces, and the sealing surface to the mating part. The metering hardware lives in and on it; the housing gives it a home, the ports, and a leak-tight mount.

Key Functions:

- Houses and locates the gas fuel control components
- Routes gaseous fuel through its internal passages
- Provides the machined sealing face and mounting for a gas-tight joint

Fitment & Specifications:

- Application: Cummins C8.3 natural gas (CNG) - C Gas Plus family
- Fuel type: Compressed natural gas / gaseous fuel only
- Part: 3934703 fuel control housing (housing only - not a loaded assembly)

Verify fitment with us before ordering to ensure the correct part for your application.

Purpose of the Part

It's the body the fuel control components bolt to. Nothing about a bare housing meters fuel on its own - it holds the parts that do, feeds gas through its passages, and seals to the mating component. When you buy the housing, you're buying the casting; you move your good internals over to it.

Issue Symptoms / When to Replace

A housing fails as a casting, not as a metering device, so look for:

- External natural gas leaks at the sealing face or ports
- Cracks or porosity in the casting
- Stripped, galled, or pulled threads at mounting or fitting bosses
- A warped or damaged sealing surface that won't hold a gasket

If you've got rough idle, surging, or AFR problems, that's usually the metering components inside - not the housing itself. No verified fault code points at a bare housing, and I won't invent one; gas leaks here show up as a leak, not a code.

Brand Information

Cummins has built the C8.3 and its natural gas variants for decades, so a genuine Cummins fuel control housing comes off the same specs as the original - the passages, mounting faces, and sealing surface are cut to match the mating parts on your engine. On a gas joint that's what counts: an OEM casting seals flat and holds the components where they belong. Cummins is a global engine and components maker covering on-highway trucks, buses, construction, ag, and power generation.

Installation Notes

- Housing only - transfer your working metering components over, or confirm what's included before ordering.
- Bare casting has no electronics, so the housing itself is plug and play - no calibration for the housing. Any metering component you move over may still need it; confirm for your engine serial.
- Gas leak check after install - soap-test the joint and fittings before any start attempt.

How to Identify an OEM Part

The cast-in number is your tell. Genuine Cummins will have 3934703 cast into the body, and OEM/reman castings run duller and rougher than the shiny aftermarket copies. Read the casting and match it before buying.

Why buy from Wisent Parts
  • ⏱️
    Fast shipping
    Orders before 12PM EST ship same business day.
  • 🛡️
    180-day warranty
    All parts covered from delivery date.
  • ↩️
    Easy returns
    30-day returns.
  • ✅
    Verify fitment
    Send VIN/ESN and we’ll confirm.

Shop with confidence

Warranty & Return Information
Warranty Information

Wisent Parts offers a 180-day warranty on all parts from the date of delivery. This warranty covers orders placed directly through our website. If a part fails during this period, we’re here to help - whether it’s a replacement, repair, or refund. For full details, refer to the Warranty page.

Return Information

Wisent Parts accepts returns within 30 days of delivery. All returns are subject to a restocking fee. To qualify, parts must be unused and in their original condition. For full return instructions and restocking fee details, please refer to the Returns page.