Little update, I'm still waiting for a good weather for doing those tests.... the car since the day I opened this thread is working ok, idle always perfect (1200rpm cold then 900rpm warm), no more 1600rpm during driving... I dunno, this car is joking to me?
Hello everyone, another big update. My car, since 2 months (basically the time I sent the last reply) is driving perfectly. Idle is perfect around 875, 900 rpm warm, 1200 with cold start... driving smoothly and I did nothing to throttle valve or other parts of the engine. Could be something related the warm weather? Because I had this big issue only in winter weather with rain and umidity...
An update on my daughter's car. Things got worse and she got fed up with it so I changed the idle control valve. The idle is now totally steady as it should be.
Also I helped a friend with an older MEMS 1.6 system. This car had a potentiometer on the side of the throttle body. I read that this should be at 0.4 volts with throttle off but we couldn't achieve this with his so bought a new potentiometer. This fixed the idle on his car. The fix involved fitting a new potentiometer and then physically twisting and shimming it so that it reads exactly 0.4V (read in live data on pscan). It was quite sensitive and only idled properly once it was set right. After adjustment the ECU was calibrated by something like:-
Ignition on
Press throttle slowly five times.
Wait a minute.
Ignition off.
This from memory so Google it.
