Regarding EFI idling

[chipis]

Hello,
have some problems with bosch two pin idle valve controlled by the ecu adaptronic 420d, cannot get normal idling at all, maybe someone could share some basic settings where i could start from fine tuning?
what frequency i should set on ecu for valve? has it be inverted or PWM? and with what number i should start PID table?

thank you for the support

[Scoff]

First of all you must be sure that the fuel and ignition maps are good. So make sure it is idling well without the idle control valve. Use the throttle stop screw or air bypass screw to set idle at 850rpm, or whatever.

Of course, if the fuel or ignition map is poor around idle then it wont idle properly.

Once you are happy that the fuel and ignition is good and you have a stable idle without the idle control valve then you should set the idle control valve like this:

1) Return the throttle stop and byoass screws to normal.
2) Connect the idle control valve, one pin to ignition live and the other pin to AUX 1,2 or 3 on the ECU. (It must be 1,2 or 3)
3) Enable PWM on this output.
4) Set PWM frequency to 50hz
5) Disable closed loop idle control (so set zero for all P,I & D loop settings in the idle settings)
6) Use the "Base idle value (based on coolant temp)" table to set your idle duty compared with temperature. You should maybe start at 50% in all boxes. Start the engine and note the idle speed. If it is too high then reduce these numbers. If it is too low then increase them.
7) Once you have found a good duty % for a hot idle then you can enter slightly higher values for cold temperatures.

There are some short cuts and tricks to speed the programming up but they are very hard to describe here. One trick is to set the idle table to 80% everywhere and then use the "Max value" on the idle tab to start at 40% and increase this number until you find a good idle speed. Once you find a good speed then you can use this value in the "Base idle value" table and restore the "Max value" to 100%.

Chris

[chipis]

thanks! is there any difference which pin will go to +12V and which one to aux output? because none of the pins are market on the valve

[Scoff]

You can wire it any way :)