Flexfuel sensor turning off kpro board
Posted: Sat Jul 15, 2023 3:17 am
2003 S2000 with K-Pro4 serial 42646, kmanager 4.5.5
I've been running with this ecu for several years, right now it is on a SC setup.
Latest modification was new EV14 1500cc 8.5Ohm injectors and GM #13577429 flexfuel sensor.
After this I have had major problems when trying to start the car.
At first I thought it was a low cranking voltage problem so replaced battery, ground cables etc but no change.
Now I have found and isolated the problem to the flexfuel sensor.
Sensor is powered on with ignition.
If I turn on ignition with sensor unplugged, kpro board turns on like normal.
If sensor is plugged in no led's light up on kpro board, only one green led on the S2000 adapter board closest to ecu plugs turn on.
What's even more weird is if I have a laptop connected via usb and turn on ignition, kpro boards starts up like normal.
Laptop has to be turned on but I do not need to have kmanager running.
As long as I can get through the starting problem sensor is working and reads correctly.
I also found this seems to be a known problem since many years ago viewtopic.php?t=21028
Is it some kind of hardware problem and what is the best known solution?
I've been running with this ecu for several years, right now it is on a SC setup.
Latest modification was new EV14 1500cc 8.5Ohm injectors and GM #13577429 flexfuel sensor.
After this I have had major problems when trying to start the car.
At first I thought it was a low cranking voltage problem so replaced battery, ground cables etc but no change.
Now I have found and isolated the problem to the flexfuel sensor.
Sensor is powered on with ignition.
If I turn on ignition with sensor unplugged, kpro board turns on like normal.
If sensor is plugged in no led's light up on kpro board, only one green led on the S2000 adapter board closest to ecu plugs turn on.
What's even more weird is if I have a laptop connected via usb and turn on ignition, kpro boards starts up like normal.
Laptop has to be turned on but I do not need to have kmanager running.
As long as I can get through the starting problem sensor is working and reads correctly.
I also found this seems to be a known problem since many years ago viewtopic.php?t=21028
Is it some kind of hardware problem and what is the best known solution?