hopefully someone can help me here as this is really doing my head in now

basically my Si will hang at around 1500rpm and seems to take ages to drop to a normal idle speed. when i first start the car it is fine but it is only once i move off, for example when i drive off and come to standstill it stays at a high rev but will drop eventually. it doesnt seem to matter if the car is cold or warmed up nicely either

i have cleaned the ISCV, changed the TPS, cleaned the MAF, had inlet checked for airleaks, throttle body cleaned and recently changed the speed sensor but it still does it

anyone got any ideas??

John

 

fella try the coolant temperature sender either in the top hose or on the head but first disconnect the battery for half hour see if that puts it right if it does get it scanned but u will need to wait until the fault comes back first

 

sounds like a simple suggesting but have you run the car with the iscv unplugged? i cleaned mine out and tried everything else only to find the actual unit was knackered. i just drive round with it unplugged for now till i fit the new one i got

 

that is going to be my next point of call

should there be any difference in the sound of the engine when you unplug this ie should it drop revs etc..?
i have got a brand new one that i am waiting to buy

 

will have a look at the temp sender but i have tried the battery disconnected route and it didnt do anything

 

Is it when you start your car from cold it idles normal but as soon as you touch the throttle and release it revs up by itself and as soon as you drive down the road it stops?

I am thinking CTS as it seems temperature related an incorrect CO mixture can also cause this.

Martin

 

not really as it does seem worse once the car is warmed up or ive been on a run

basically when i touch the throttle it sticks at around 1500rpm for too long if you know what i mean

 

yeh the revs will drop and the car will either idle so low it will try and cut out, or (like mine) it will find itself after 10-15seconds. although it'll still idle very low so you will have to give it a few turns on the idle speed screw next to the inlet. as soon as i unplugged it i rev'd it up and it dropped back down fast like it should unlike before