MembersPage/MattiasSandgren/AudiQuattro (2005-08-20 16:45:08)

Leifs Audi 80 Quattro

leif1.jpg

Basic engine specs:

2.0l 16V ABF, head KR, lowered compression, JE pistons, Verdi rods, custom turbo cams, Holset HX50 turbo, custom intake and exhaust manifold.

Engine management:

Genboard v3.2, stock VR trigger, sequential fuel injection, MSD6 ignition amplifier using stock distributor.

Emil and others helped get this car running and I could tell you more about the tuning issues but that's not important as they can all be solved and is not Genboard-related.


EGT issue

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

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.

Now, disconnect the carburators and run the fuel injectors from VEMS, and the temperatures in the VEMS reads 1100 degrees C. The Fluke meter still reads about 700 degrees C if you connect the EGT probe to it.

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.