Engine Management For Gasoline, LP, CNG, Dual-Fuel Uses

Diesel Progress North American Edition, Sept, 2001 by Mike Osenga

Precision Governors LLC has introduced an EFI engine management system for gasoline, LP, CNG and dual-fuel industrial engine operation. Initially introduced for the Ford 1.3 L model 413 engine, Bob Dayton, company president and CEO, said the system is designed for complete engine management, including electronic fuel injection, spark control and engine governing.

Targeted equipment for this EEL system with the 1.3 L engine includes industrial sweepers, aerial platforms and scissors lifts. Other engine sizes and use in other types of equipment are currently being studied, Dayton said.

Formerly known as Precision Governors Inc. (PGI), the Rockford, Ill., company was sold in April to Chartwell Holdings Inc., with PGI founder Hal Meyer remaining as a consultant to the new company Dayton is president and Bill Earls is general manager of the newly formed Precision Governors LLC.

The EFI system Precision Governors is now taking to the industrial engine market is designed as an engine management system that includes a governed throttle body assembly, a digital ECU, engine management software, engine sensors, along with additional system hardware.

"One of the keys to the system is that we're not using radically new products or technologies," Dayton said. "We're combining Precision Governors' digital electronics expertise with an array of proven, readily available automotive components."

The system is designed to provide governed speed control with a fast-response Precision Governors-built actuator. It is dual-fuel capable via an in-line LP mixer system from either Nolff's or Impco that is connected to the throttle body air horn. The ECU allows up to four discrete speeds to be selected, ramp-up and rampdown, or drive-by-wire, and it stores engine calibrations for a variety of fuels.

Additional customizable features include overspeed protection, overtemperature and low oil pressure shutdowns, starter lockout and external shutdown input.

The governed throttle body assembly includes: a Delphi fuel ring injector subassembly that includes the fuel injector and pressure regulator; a new, Precision Governors-built fast response (45 msec), low inertia actuator; an inlet air temperature sensor; a throttle position sensor; throttle body heater unit; and the inlet air horn that is designed to allow the air intake to be positioned in any direction, Earls said.

The same throttle body can be modified by changing the bore size and using a different injector to create a system for other engine sizes, specifically in the 1.3 L to 4.2 L range. "The modularity of our system means that it can be easily scaled to other engines," Dayton said. "We're not locked into any specific displacement."

The digital ECU is designed and manufactured by Precision Governors. All of the calibrations for gasoline, LP, CNG and dual-fuel operation are on the same board. The board itself is four-layer, surface-mount technology in a housing that is potted and sealed with epoxy against the operating environment with heat sinks for cooling. The ECU is mounted away from the throttle body, Dayton said.

Four engine sensors are included; a MAP (manifold absolute pressure) sensor, inlet air temperature sensor, throttle position sensor and an engine-coolant temperature sensor. The additional system hardware includes an electric fuel pump, power relay for the fuel pump, ignition and fuel injector, and an engine manifold mounting adapter.

Besides its work in the gasoline and dual-fuel markets, Precision Governors also has an active diesel engine control program including two digitally controlled linear actuator systems that controls the fuel rack of off-highway diesels. For these applications, which have been in production manufacturing for three years, Precision Governors supplies the linear actuator, digital controller, and a LED digital display that was designed specifically for each application.