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There is trouble with the exhaust gas temperature measurements.
Apparently the egt1_cal is not calibrated properly. I took some notes on GenBoard/Manual/ExhaustGasTemp |
| There is trouble with the exhaust gas temperature readings, see GenBoard/Manual/ExhaustGasTemp. |
| Last year the engine ran on carburators with the MSD6 and the temperatures were normal, about 700 degrees C measured at an exhaust port close to the head using the Fluke as the EGT meter. With the VEMS measuring EGT and the carburators handling fuel, it measures the same and all looks well. |
| Back in 2004 the engine ran on carburators with the MSD6 and the temperatures were normal, about 700 degrees C measured at an exhaust port close to the head using the Fluke as the EGT meter. With the VEMS measuring EGT and the carburators handling fuel, it measures the same and all looks well. |
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I would have to get some good pictures of the board to tell you how the EGT chips are soldered and configured. But the board is a couple of hours away from me in the car, so maybe later this fall. For now, the Fluke meter can be trusted.
Any input is appreciated. Jörgen: The fact that the sensor show correct numbers when the ECU doesn't handle fuel make me suspect a ground problem. The heavy load placed on the ECU by the injectors can cause this. The EGT sensor is the most sensitive sensor we have, 1000C is only 41mV! Make sure that the sensor is isolated by making sure that the resistance from the sensor wires to GND is in the Mohm range with the sensor unplugged from the ECU. If the sensor is not isolated it's very important that the grounds are VERY strong and nothing say that it will work anyway as only a few mV make a huge difference. |
| This problems is solved by turning off PWM as that mechanism is what causes the ground issues. This means running the injectors in saturated mode with a big transient suppression diode to better control closing time of the injectors. |