The LPG/CNG Feedback Fuel Controller uses EEE TEE Digital Design's unique digital Dynamic Alternate Fuel Controller and is designed to maintain a stoichiometric fuel mixture.  It functions very similarly to Dual Curve's PN 5952 Digital Fuel Controller but improves upon Dual Curve's design by incorporating an on-board monitoring system directly on the module.  This controller includes the equivalent of the Dual Curve PN 4041 - Mixture Monitor.  While this feature is an extra cost item from Dual Curve, it is integrated into this controller, which accounts for the higher cost of this item compared to the PN 5952.

This system allows for the continuous monitoring of the operation of the controller and simplifies the set up for the technician without the purchase of additional monitors or instrumentation.  The module includes combination lights including a power and failure light, warm-up and O2 light, and individual lights that monitor the amount of modulation during fuel mixture control.

For monitoring capability, the Controller has an output for an optional, dash-mounted warning lamp.

Although designed to be compatible with Impco systems, it is also compatible with most gaseous fuel systems using either LPG or CNG.  For vehicles with catalytic converters in the exhaust, the use of a feedback air-gas valve is required to maintain a stoichiometric fuel mixture for low emissions.  For off-road vehicles without a catalytic converter, this controller may be used with the standard and lean gas valves to ensure that fuel economy does not suffer when the engine is warming up.

This fuel controller is very easy to set up.  For both idle and full-throttle power for feedback operation, the fuel mixture should be adjusted so that the controller alternates evenly between rich and lean operation.

For systems without feedback gas valves, after reaching operating temperature, set the idle for the highest and smoothest idle and set the power adjustment for best power on the lean side.  This is usually about 2% exhaust CO at maximum load.  When the engine is cold, the controller will keep the fuel mixture from becoming too rich.  With short trips in cold climates , this makes a big difference and has a fast payback.

The Fuel Controller package consists of the following items:

  • 1 x EEE TEE Digital Design PN FC-495-X Alternative Fuel Closed Loop Controller
  • 1 x Impco HK-54702-001, Vacuum Control Solenoid
  • 1 x Gann VF-2 Vacuum Fitting, Brass, ¼" Hose x ¼"-28 MFT
  • 1 x Gann 21EN Vacuum Elbow, Nylon, ¼" Hose x ¼" MNPT

We recommend using a heated O2 sensor with this item if the vehicle does not already have an O2 sensor.

A single Fuel Controller may also be used to control two converters with the addition of a vacuum Tee, which can be purchased from any autoparts store.

LPG/CNG Feedback Fuel Controller

  • $385.21