Vems ign based idle cold start

[Error404]

10-15deg sounds in the right ball park. What I would do is find approx MBT at idle at normal operating temp, then retard say 5 deg timing, adjust idle ariflow to give you approx your chosen idle rpm, then you know you have a good range of timing for the idle control to play with. If you are at MBT already and the engine is struggling to hold idle, then the ECU has nothing to work with. Obviously fueling needs to be correct first. Do you have a pre-heat function for the lambda sensor in VEMS? Could help to help you find the right compensation on cold start = lambda sensor comes online quicker - still some trial and error though.

[s2dk]

hey.. a80avant is very helpfull (i hope) havent tried his doings yet haha. but i will keep in mind

[QuattroFever]

10-15deg sounds in the right ball park. What I would do is find approx MBT at idle at normal operating temp, then retard say 5 deg timing, adjust idle ariflow to give you approx your chosen idle rpm, then you know you have a good range of timing for the idle control to play with. If you are at MBT already and the engine is struggling to hold idle, then the ECU has nothing to work with. Obviously fueling needs to be correct first. Do you have a pre-heat function for the lambda sensor in VEMS? Could help to help you find the right compensation on cold start = lambda sensor comes online quicker - still some trial and error though.

^^^
Yes! Check your lambda sensor has the heater wired up. Will help you dial in cold start settings.
I relayed mine from a switched live from the ignition. Correct wideband Calibration needs this as well.

[customizer]

Very helpful, thanks

[s2dk]

i did go back to using the isv btw.. i never got the cold start to work that well..