My S1 Exige idles completely normally when stationary, but as soon as it is moving (with wheel rotation detected by the right rear wheel speed sensor), the idle speed flares to about 2200rpm. The effect is reduced as the car warms up, but even when completely warmed up the ‘rolling’ idle speed remains high.
So far I have:
Reset the TPS using the normal procedure
Removed, cleaned and refitted the Right Rear Wheel Sensor
Removed, cleaned and refitted the IACV
Replaced the Brown Temp Sensor
Disconnected the Battery for an hour or so in the hopes that it may put the ECU back into a learning mode (yeah, I know, clutching at straws)
Does anyone have any other good suggestions before I commit to taking it in to a dealer or independent? Although not a major problem, it really is driving me mad!
Get an Emerald.
Seriously, mine did this from time to time on a random basis… having tried all you have too! Have you also tried reversing!
Emerald is the way to go!
You’ve probably seen my post on this subject, but when I had the same issue, it was the right rear wheel speed sensor. I cleaned the pins and connector with electrical cleaner, repositioned the sensor (centralised), problem cured
Good luck - it drove me mad every time I went out in mine
Yes, tried the wheel sensor once but I guess I’ll try it again and make sure that it’s centralised then …
However, the fact that the wheel sensor is detecting wheel motion would seem to indicate that it is probably not the main reason …
In fact, with the car jacked up, spinning the right rear wheel reproduces the effect exactly which indicates that the wheel sensor is working (ie detecting wheel motion?)
Any ideas most welcome!
Possibly the throttle body butterflies sticking slightly open?
Incidentally … For the TPS reset/recalibration procedure, does it matter whether the immobiliser is active or not in order for the MEMS ECU to accept the new datum?