COMMANDER lDx- AIR/FUEL CONTROL UNIT
US Government vehicles converted by Carburetion and Turbo Systems Incorported
|FUEL SYSTEM ANALYZER|
IMPCO Technologies Incorporated
INDUSTRIAL 6 CYLINDER APPLICATIONS
IMPCO PART EKCDP-lDx-4 & -6
This document will show you how to install the IMPCO Commander fuel control processor for industrial engines. The Commander 1Dx kit contains all of the electrical components required to convert your IMPCO open-loop fuel system to a state-of-the-art closed-loop fuel control technology. Please check the components parts list to be sure your kit is complete.
The Commander is an advanced digital closed-loop fuel control processor for alternate fuels. This kit supplies the required electrical parts to convert IMPCO open-loop fuel systems to closed loop feedback control. This IMPCO controller provides an overall reduction in exhaust emissions without catalytic converters. The Commander's compact construction provides for an ideal under hood package, hermetically sealed for operating in harsh environments. The small electronic module controls fuel pressure based on engine speed and rich/lean status from the oxygen sensor. The Commander's microprocessor reads and computes this data one hundred times per second, which gives a precise stoichiometric air/fuel ratio. The IMPCO Commander delivers good exhaust emissions, drivability and fuel economy at a reasonable cost. The fuel controller is compatible with all current IMPCO feedback mixers.
COMPONENT PARTS LIST
BEFORE YOU BEGIN
Although the Commander is easy to install some special tools are required to properly adjust the air fuel mixtures and verify proper system operating pressures.
The IMPCO FSA-1000 or FSA-1 fuel system analyzers are used to set the fuel mixture and duty cycle. This is a required tool for the Commander installation and is also used on other IMPCO closed-loop fuel systems. The ITK- I pressure test kit is used to verify system fuel pressures. The IMPCO ITK-1 pressure test kit is a required tool for all IMPCO fuel system diagnostic testing. When converting a open-loop system to closed-loop you will also need to change out the standard air gas valve, or complete carburetor with a (FB) feed back air gas valve, or complete carburetor. The FB valve is not included in the Commander kit. See TABLE ONE FOR SPECIFIC AIR GAS VALVE RECOMATIONS
The Commander processor’s intended use is with volatile
and if improperly installed may create a hazardous condition.
The Commander processor is a stand-alone unit. It has no interface capabilities to a factory onboard computer.
During the installation of the Commander, if you come across unfamiliar or potentially hazardous conditions, call your local IMPCO distributor for clarification before proceeding.
To prevent ignition of leaking gaseous fuels that may cause a fire and/or explosion, avoid open sparks, flames, and operation of electrical devices in or about the engine compartment.
Always follow installation regulations that apply to you. These requirements are found in NFPA-52 for natural gas. This is a U.S. standard. For Canadian codes see National Standards CANADA. Additionally, some Countries or provinces may also have certain requirements of which you must be aware.
1 . The Commander is under hood compatible and is hermetically sealed to operate in harsh environments. However, the Commander cannot be installed near high temperature sources such as exhaust manifolds or high-tension spark plug wires. Determine a suitable location for the Commander module. An ideal mounting location is on the firewall. Mount the Commander securely on a flat surface using the mounting holes provided. Do not distort the base of the unit.
2. Install the recommended IMPCO fuel system components for your specific application (Commander requires an FB series carburetor/ mixer). Preset the fuel power adjustment to the middle of the rich/lean scale. Install the IMPCO fuel control valve (FCV) on the regulator/converter assembly, as shown in Figure 1.
The FCV must have an independent air valve source from the IMPCO mixer/ adapter. Keep these vacuum lines as short as possible.
3. Route the Commander wire harness leads to approximate terminations using the wiring system schematics. Secure the harness leads away from high heat sources and moving parts.
4. Prepare to install the supplied oxygen sensor. The supplied sensor should be mounted near the closest exhaust valve. This could include the exhaust manifold, or there may already be a port to install the sensor.
This kit supplies a mounting boss for the sensor. This
be welded to a convenient location on the manifold or on a section of
exhaust pipe header.
Remove the exhaust piece from the engine that you will modify for the sensor installation. We do not recommend sensor boss welding while still mounted to the bus.
Drill or punch a 7/8" hole to the area you wish to mount the sensor. Thoroughly clean and debur this hole to prepare for welding.
Place the oxygen sensor boss shoulder ridge down and clamp in place. We recommend lightly installing an old spark plug to the boss to protect the threads from damage during the welding process. Place a generous weld bead around the entire boss. Let cool, remove the spark plug and check the thread integrity by installing the oxygen sensor. It should screw down flush easily finger tight without the use of a wrench to the contact gasket. If not chase these threads with a tap until this can be achieved.
Torque the sensor to 41 N-m (30 ft. lb).
5. Mount the FCV (fuel control valve) near the IMPCO vaporizer/regulator. Install the tee fitting to the vent port on the IMPCO regulator converter with the 5/32" hose nipple toward the FCV. Insert the J1-21 (0.100") orifice into the 3/8" tee nipple and attach the hose. Connect the other end of this hose to a filtered air supply. If a balance line must be used please read the "Tips and Tricks" section of this manual.
Trim and connect a suitable length of supplied vacuum line to the fitting and connect to the FCV port identified in Figure 1. It is important to follow this recommendation, as the valve is directional.
Remove one of the 1/ 4" x 28 air valve vacuum screw plugs from the IMPCO mixer. Install the supplied F4-40 vacuum fitting. Cut a suitable length of supplied vacuum line to reach between this vacuum fitting and connect to the remaining port on the FCV and the newly installed F4-40. Keep these lines as short as possible.
2. Connect the Commander red wire to a switched +12 volt source through the 5-amp fuse. This source must be hot with the key in the "START" and "ON" positions. This source should not supply power with the ignition key in the "ACCESSOR" position. For dual fuel vehicle installations the switched + 12 volts, source must be wired through a fuel selection switch. This is to cut power to the Commander during gasoline operation. Direct power is applied through the key switch only on dedicated, single fuel systems.
3 . The black ground wire must be attached securely to an engine ground. Terminate the wire with suitable connector and attach to an engine ground using a #8 or larger screw.
4. Connect the Commander white wire to the vehicle negative terminal of the ignition coil. Consult your factory service manuals ignition diagram for this connection if you are not sure.
5. Connect the violet and yellow wires to the fuel control valve. The FCV has no polarity; either wire can be connected to either terminal.
6. The red, black and green wires terminating at the connector are plugged into the HEGO sensor located in the exhaust pipe or manifold.
7. Connect the grey alarm lead to the indicator light black lead. Connect the indicator light red lead to a 12-vdc-ignition source. The indicator light turns on when the fuel mixture is rich more than two minutes.
IMPCO Fuel System Analyzers
The Commander is designed as an independent fuel control processor. However, it is very important that all existing onboard controls and sensors work properly. Many engine-operating problems are due to malfunctions of the existing gasoline systems equipment. Make sure the following engine systems are to specifications: ignition, timing, valve adjustment, exhaust and cooling. Also assure that the IMPCO fuel control system components have been installed properly and the fuel pressures have been tested before adjustment.
The Fuel System Analyzer (FSA-1000 or FSA1) must be used to adjust the IMPCO fuel management system. Always verify emissions with a CO meter after FSA adjustment.
Connect the FSA according to the instructions that came with the unit.
If using the FSA, hook up the unit's black lead wire to ground, red to + 12 volts, green to the oxygen sensor and yellow to the yellow wire of the FCV.
Idle Mixture Adjustment
Ensure that the vehicle's engine, transmission and hydraulic system are at operating temperature before taking fuel system readings or making adjustments.
1. Determine if the vehicle has feedback control during idle
2. When the vehicle has feed back control at idle, adjust the IMPCO carburetor idle mixture adjustment screw until the "COMPUTER COMMAND" reading on the FSA is approximately 50. By setting the reading as close to 50 as possible, the controller has full range to go rich or lean. The "50" is the perfect number. You may see swings between 30-70. This is an acceptable range. The LED lamps should transition from rich to lean in a fairly regular mariner.
A vehicle with feedback control at idle should show significant change in the "COMPUTER COMMAND" when turning the idle mixture adjustment screw.
Power Mixture Adjustment
Tilt relief is full throttle, continued hydraulic loading at maximum travel of mast tilt. The transmission must be in neutral.
Adjust the power valve slowly and allow at least 30 seconds for the reading to stabilize.
Final Load Check
1. During the load test the "COMPUTER COMMAND" should remain
30 and 70 under normal "closed-loop" operation. This verifies
the computer has the amount of control necessary to keep the fuel
If you are unable to achieve this, verify that the OEM system is functioning properly, determine that the alternate fuel system is also operating correctly. Test the operating fuel pressures with the ITK-1 pressure test kit. Check both primary and secondary pressures. Always disconnect and plug the vacuum line from the carburetor to the fuel control valve when checking pressures. A fluctuation will occur with the line connected. Compare these steady pressures with the specifications of the regulator you are using. Refer to the IMPCO Material Handling Catalog for specifications.
Refer to publication part number 23800-27, "Fuel System Analyzer Instructions" for additional information on IMPCO closed-loop feedback systems.
TIPS & TRICKS
Due to friction within the installed balance line, it may be necessary to use the larger 0.100" restrictor. This proves to be suitable for balanced systems where the balance line is at least 24" long.
The technical information, specifications, data and assertions regarding the products described herein is believed to be accurate and complete. However, no representation or warranty is made with respect thereto except as in writing at the time of sale. IMPCO does not warrant that the products described herein are suited for any particular purpose except as IMPCO may warrant in a separate writing at time of sale. In the event of a conflict between the IMPCO drawings, specifications, and warranty for the product described herein and this document the IMPCO drawings, specifications and warranty shall have precedence.
Commander 1Dx Specifications
Power: 10.5 to 14.5 V DC
Power Protection: 5-arnp fuse
Diagnostics: Connection to FSA-3 analyzer
Temperature: 20oF to 250oF
Alarm Circuit: I 00 ma max.; grounds light with system rich
Idle Memory: Updates after 3 minutes of idle
02 Sensor: Heated 3-wire
Sensor Output: 0.0 to 1.OV DC
Sensor Life: Approximately 2,000 hours
Fuel Control Valve: 0 to 200 ms off time
For millions of drivers in the U.S. and around the world, an experience like that is a daily occurrence. Diesel-powered trucks and buses crowd the nation's roads, and each one contributes to the fouling of the air we breathe. Beverly Miller is Director of the Salt Lake Clean Cities Coalition (SLCCC), a non-profit organization dedicated to promoting the use of alternative, cleaner fuels for transportation. "What we really need to be doing," she says, "is addressing those big diesels, because they are the big polluters, puffing and snorting around."
Is there an alternative to the big rigs powered by diesel fuel? Yes, and for several years the Idaho National Engineering and Environmental Laboratory has converted vehicles in INEEL's fleet from gasoline and diesel to a cleaner, less-polluting fuel. Furthermore, if engineers and scientists in Idaho Falls have their way, they will establish INEEL as a national center of expertise in developing this alternative source of energy, especially for heavy-duty transports like trucks and buses. The alternative fuel is liquefied natural gas, or LNG.
Used in a test fleet in California, LNG was almost unbelievably clean. Emission of ozone-forming compounds was down 70-80 percent, of carcinogenic particulate matter, down 90 percent, and of unburned fuel, down 50-60 percent. These were among the lowest levels ever measured from heavy-duty vehicles.
Scientists and engineers at INEEL know that before this cleaner fuel can be widely used in heavy-duty vehicles, several things have to happen. Facilities must produce liquefied gas that is uniform in quality, refueling stations must be built, and vehicles must be modified to take the fuel. Above all, if LNG is to become a permanent part of transportation, the fuel must be competitive in price with gasoline and diesel.
Wilding's group designed and patented an ingenious methane plant, a low-cost refueling station, and an engine modification that will allow the efficient use of LNG in trucks and buses. With an increase in public awareness of how clean LNG burns, and with the right kind of support, they believe that within a couple of years, LNG vehicles could be a common sight in Idaho and Utah. Prove the concepts and the vehicles to be successful in those two states, and they could soon be in use nationwide; all because of three licensable technologies developed at the INEEL.
The Methane Liquefaction PlantNatural gas flows from oilfields and gasfields across the country, through high-pressure pipelines to distribution centers and ultimately to consumers. To liquefy natural gas, you can compress it, or you can chill it. If you compress it, you get a liquid that is a mix of substances and variable in quality, not always suitable for vehicles. But just as water vapor condenses to liquid water on a cold surface, so natural gas will liquefy if you lower its temperature far enough. And as you lower its temperature, the different components in the mixture become liquid one by one and can then be removed. Butane, propane, and ethane become liquids at successively lower temperatures, until the only gas left is the one you need to liquefy for the heavy-duty vehicles: methane, with a purity of 98% or better. The ingenious part of this chilling process lies in the use that can be made of the separated liquids during the purification of the methane. For as a liquid expands to become a gas, its temperature drops. The butane, propane and ethane liquids are each separated and then allowed to expand, whereupon they become cold gas again, which can then be used to cool the complete natural gas mixture coming into the plant to be processed. Eventually, the separated gases are pumped into tanks for storage and sale, but in the meantime, they have also contributed to an inexpensive, efficient process for producing clean and pure LNG.
The Refueling StationThe typical LNG stations are expensive, because of the special equipment needed to store and dispense a liquid at a temperature of -200 to -260 degrees Fahrenheit and a pressure of 25 to 135 psi. Researchers at INEEL sought simple ways to store and pump the fuel. Their design for the refueling station uses the physical properties of the liquefied fuel to provide the force needed to transfer the LNG from the tank of the station to the tank of the vehicle, and reduces the cost to $100,000 or less, competitive with gasoline stations.
Liquefied natural gas must be stored cold and sealed. If its temperature rises, some of the liquid vaporizes to gas above the liquid surface, and raises the pressure of that gas. The INEEL plan is to store the fuel very cold, so that the pressure of the gas above the liquid is about 25 psi. In the vehicles coming in for refueling, however, the temperature of the fuel in their tanks may be higher than that in the station, and the pressure of the gas correspondingly greater. This means that an expensive pump would be needed to force the fuel from low pressure in the station to higher pressure in the vehicle. But the staff at INEEL devised a way of maintaining a high pressure above the liquid in the storage tanks of the station, thereby eliminating the need for the pump.
Their design is to bleed off the liquid gas from the bottom of the tank, warm it and vaporize it in a coil that draws its heat from the surroundings. The gas is then discharged into the top of the storage tank, increasing the pressure there, which can drive the refueling process. At the same time, a small pump sends a quick surge of very cold fuel into the tank of the vehicle. This chills the fuel, causing some of the gas above the liquid to condense, thereby lowering the pressure. The fuel is then being transferred from high pressure to low pressure so that no more pumping is needed. Gravity and the "false pressure" created in the storage tank combine to fill the tank in the vehicle.
The Engine ModificationIn an LNG vehicle, the engine draws liquid from the bottom of the tank, or gas from the top, depending on the pressure of the gas and the setting of a special valve called the economizer valve. With a pressure below the valve setting, the engine draws liquid; with a higher pressure, gas. When the fuel is very cold, the engine can suffer fuel starvation during acceleration or when under a heavy load. Engineers at the INEEL changed the piping of the fuel system to prevent fuel starvation.
Ingenious and economical though these innovations may be, the real test of LNG will come on the road. For several years the INEEL has operated buses and trucks running on LNG, and four buses went to Atlanta to serve as part of the transportation fleet for the 1996 Olympic Games. Based upon that success, the engineers and scientists at the INEEL proposed a project to expand the use of LNG heavy-duty vehicles in Idaho and Utah. It will be a collaborative effort with the Utah Energy Office, the Salt Lake Clean Cities Coalition, Utah Transit Authority, and Questar Regulated Services Company to install a methane liquefaction plant and a refueling station to supply transit buses and other heavy-duty vehicles in Salt Lake City and its suburbs.
"We are absolutely delighted and thrilled to be part of INEEL's project," says Beverly Miller, "for we need to convince owners and drivers that if they use LNG, they can save dollars. And natural gas as a transportation fuel has an extremely impressive safety record." As an example she cites the experience of the Newspaper Agency Corporation, the company that home-delivers the Salt Lake City Tribune and the Deseret News. Of their 250 vehicles, 238 are powered by natural gas in one form or another, and they drive six million miles a year. Miller believes that the tradition of using natural gas vehicles in the Salt Lake City area makes it an ideal market for the INEEL proposal.
Safe, effective and cleaner than diesels, the LNG vehicles would also be as economical as the big rigs and buses if there were filling stations and liquefaction plants around the country. The vision of the framers of the INEEL project is to achieve that goal. Build an economical LNG infrastructure in Idaho and Utah, and then convince the rest of the country to do the same. California would be one of the first candidates, with its smog problems in the Los Angeles basin and elsewhere.
Already in the Sacramento area, one company is trying out heavy-duty LNG trucks. Raley's, a chain of grocery markets in northern California and Nevada, bought eight big trucks in 1997. Kathleen Tschogl (pronounced Shagle), Manager of Governmental and Regulatory Affairs for Raley's says "We are very pleased with the program and are looking at ways to expand it. They were unbelievably clean."
They are clean of that cloud of smoke and particles that comes from diesels. Not merely unpleasant, the emissions from the big rigs are dangerous. The U.S. Environmental Protection Agency describes hydrocarbons from incomplete burning as toxic and possibly carcinogenic. When they combine (in the presence of sunlight) with other emissions like nitrogen oxides ("noxes"), they form ground-level ozone, a major component of smog and a cause of reduced lung function in humans. The black and sooty particulate matter that is spewed by the exhausts of diesel-powered vehicles lodges in the lungs, perhaps causing premature death. The State of California has recently concluded that exhaust particulates are carcinogenic.
Kevin Chandler is principal research scientist for Battelle, contractor for the National Renewable Energy Laboratory, monitoring the Raley program. He compared the emissions from LNG vehicles from Raley's fleet and the emissions from diesels. "The values [from the LNG trucks] were low enough that we thought there was a mistake." With a 70-80 percent reduction in "noxes", a better than 90 percent reduction in particulates, and a 50-60 percent reduction in hydrocarbons, "they were the lowest levels from heavy-duty engines we have ever received," Chandler says.
Unaware of all that the researchers at INEEL had done to advance the cause of using clean LNG fuel instead of diesel, an automobile driver sits at a light. When it changes to green, a nearby tractor and the bus move. She hears the roar of their engines, but sees no dark and billowing clouds come out into the air. The dream of engineers and scientists at the INEEL is for the moment a reality. "I want the world to get our vision," says Richard Rice, Department Manager of Advanced Fossil Fuel Products: the vision of clean, heavy-duty transportation.
Written by Robert Evans for INEEL Research Communications.