yes i know tickover threads have been done to death but i had a search and didnt find anything relevant to my problem,

 

its been like this for a while now and i just got round to investigating

 

basically the car drives and runs superb, good pickup smooth gear changes etc. auto j spec tt btw.

 

now no matter what temperature the engine either from cold or normal temp, the tick over in neutral is always 1000 rpm, if i switch the aircon on it rises slightly which i beleive is normal.

 

i think its running quite rich cos i noticed when backing up i get black smoke out the zorsts. it basically seems to me that the "choke" is stuck on all the time, so im thinking the ecu doesnt know what temp the engine is, ive cleaned the coolant temp sensor and throttle bodies. any other areas to check,

 

much help appreciated as 10 mpg is killing my wallet

It could be the TPS not being adjusted correclty - try resetting the ECU as well - see if that cures it. I have seen similar problems if the TPS is adjusted on the car while the engine is running and it confuses the ECU and idles at high values. Failing that it may just be the base idle needs adjusting - but you have to disconnect the idle control as it will compensate!

 

Plenty of write ups on how to do all those things.

Could also be a small vacumn leak. SMW1 had very similar symptoms.