Using the Eagle System to Read Air/Fuel Ratios

Transcription

1 Using the Eagle System to Read Air/Fuel Ratios _A.DOC 6/7/2012

2 Reason for using an air/fuel ratio device It is not necessary to have an air/fuel ratio to determine if the engine is rich or lean. The same techniques used on a mechanical fuel injection system with a mixture knob can be used. These are lean out RPM rises and EGT changes. These techniques are well defined in Lycoming s engine literature. One benefit of using an air/fuel ratio device is that you can determine if the engine is rich or lean just by looking at the air/ratio meter if the device comes with a display. The second benefit is if the device has an output, then it can be connected to the Eagle. The data output from the Eagle will include the air/fuel ratio which will be displayed with the rest of the data such as RPM, MAP, and BAP. The data can be saved and reviewed later to determine when the engine is running too lean or rich. Air/fuel Ratio Devices The oxygen sensor is not plugged directly into the Eagle system. The sensor is plugged into an oxygen sensor controller, which conditions the signal. The controller has an output harness that is plugged into the Eagle s ECU. We have used several different devices for measuring the air/fuel ratio and transmitting the information to the Eagle. Two of which are made by Innovate Motorsports, their web site is shown below. Their manuals are available on their web site, READ them. Many important details need to be followed for the device to work correctly! The Innovate devices that we have used are: 1. LM 1 kit includes an Oxygen (O 2 ) sensor, meter (display), and wiring. The LM 1 is no longer available and has been replaced by the LM 2, which works similar. Both of these meters have a data output cable that can be hooked up to the Eagle. 2. LC 1 kit includes an O 2 sensor, electronics housed in a connector, and wiring. There is no meter with this kit. The electronic housing does have a data output cable that can be plugged into the Eagle. The housing that contains the electronics needs to be inside the cabin like the meter from LM 1 so that the cowl heat does not over heat the electronics _A.DOC 1 of 4 6/7/2012

3 Calibrating the Innovate Device The Innovate device needs to be calibrated to output between 0 and 5 volts, this is in the range that the Eagle ECU can translate into an air/fuel ratio. The 0 volts represents an air/fuel ratio of 10:1 (fuel rich) and the 5 volts represents an air/fuel ratio of 20:1 (fuel lean). Plug the Innovate product into a laptop computer, install the Innovate software on a laptop computer, and chose the options as shown in the following photos. Choose your sensor Enter These Values _A.DOC 2 of 4 6/7/2012

4 Installing the O 2 sensor The oxygen sensor bung that is welded into your exhaust is available from Innovate or other suppliers such as Summit Racing. If you have a stainless steel exhaust system use a stainless steel bung. If the O 2 sensor is removed from the bung, plug the hole in the bung with a plug that has had its threads coated with anti seize compound. A plug with a raised hex head is preferred over one that has a recess for an Allen wrench because the Allen wrench cavity is easier to round out. The bung needs to be the correct distance from the head to keep the O 2 sensor temp from getting to hot or too cold. If the sensor gets too hot, it will be damaged and if too cold, the sensor will not read correctly. The orientation of the bung around the circumference of the pipe should be so that the sensor is inserted from the top down into the pipe NOT from the bottom up. These details are in the Innovate manual. Connecting Innovate product to the Eagle Electrical O 2 output from the Innovate products is in the form of a phone jack type plug, which is plugged into the ECU jack, which is located on bottom edge of the Eagle s ECU. The air/fuel ratio is only displayed on the LEFT ECU. The tip of the phone jack is analog channel 1. Reading the Air/Fuel Ratio with the Eagle Attach the LEFT ECU communication cable to a laptop computer. Type the command ops, the Eagle s data will be displayed. As mentioned before the air/fuel ration will only be displayed on the LEFT ECU data stream. The data will look something like what is shown below. We are only interested in two terms AFR and OXY. The AFR is the air/fuel ratio calculated by the Eagle and the OXY is the air/fuel ratio measured by Innovate. The two values should be similar. If they are not then the Eagle s ECU may need to be calibrated or the Innovate product is not calibrated or functioning correctly. PWusec VE% CHTPE% CHT IAT MAP" BAP" FPSIa PSID ADV GPH PPH MOD RPM TIME AFR OXY p :03: Leaded Fuel and the O 2 Sensor The life span of the O 2 sensor will be shorter with leaded fuel than unleaded fuel. The sensor needs to be turned on prior to starting the engine regardless of what fuel the engine is being run with _A.DOC 3 of 4 6/7/2012

5 Setting up the ECU Calibration File The Eagle system is factory set with the values mentioned in this section. The information shown here is for verifying or changing the settings if necessary. With a laptop computer hooked up to the ECU enter the command cfg, the calibration table will be displayed. The only item you are interested in is OXY. The value for OXY needs to be 001, this tells the ECU that you are using an Innovate O 2 device. For reference, a value of 000 will not display values, 002 will display the input voltage. cfg enter cfg=row,sp,col,sp,val,(cr) >GAIN <GAIN BOILT IMPCT +INDX -INDX FPTYP INJ LEAN CY PH SEQEN ECHO TSTRT TSTP OPSEN PW1 PW2 PW3 PW4 OXY MILPL F-C MAX_T MIN_T LBS+- PAGES PRIME PRTERR * _A.DOC 4 of 4 6/7/2012