idle at 1500 than 2300 rpm ??

[schakal]

the 9 had this problem since it all started and its getting a bit
annoying now :evilzz:

start the engine from cold it idles around 1200rpm which is fine for cold
engine but even when it gets hot it will idle in between 1200 and 1500 rpm .than once i go on belting mode and go over 5000 rpm on the road it will start idling around 2300 rpm and it wont go down unless engine is turned off and on again which is making it also pretty dangerous if you are like me using the compression of the engine to aid braking .

i have been told this is all to do with the road speed sensor and nothing else .my speed sensor is double-triple earthed and its still doing the same thing .in fact , i even disconnected the 3 pin plug that is on the speedo cable all together and it has not made any difference at all .

my question here is , is the idle control valve physically able to make the
engine idle over 1500 rpm ? i mean is the hole inside when fully open
able to supply enough air to make it idle over 1500 rpm ?
what i am trying to get to here is , for the engine to idle at 2500 rpm
for one reason or another ,there should be extra air getting in to the
inlet manifold as well. is the air getting through the idle control valve or
the throttle body ?

[sideways danny]

LAs randomly idled at 2k+ until i cleaned and lubricted the idle valve and changed the thermostat.

[schakal]

i will start swapping the icv for another one ,i am sure my thermostat is
working perfectly fine .

[sideways danny]

Stat needs changing a lot more frequently than you'd expect. I think changing it could improve a lot of peoples economy and poor idle. If the engine doesn't get fully warm it will just run rich. Make sure if you clean out the idle valve with something like brake cleaner, that you add a squirt of WD40 afterwards, or the valve will be too dry and stay sticky

[Wobba]

If jammed open there is enough air from the ISCV to idle at 2.5k. I think.

I'd check for air leaks though mate. WD40 around potential air leak spots and listen for leaks. Tighten jubilee's to the inlet from the ISCV. Leaks BEFORE the ISCV are irrelevant, it's the one's after.

If you've not done so, clean that ISCV!

Got a spare ECU to try?

[schakal]

dan : thermostat is not the issue , i have a secondary water temp sender fitted in the middle of top rad hose and it tells me as soon as the stat opens .

i have since changed the idle control valve and fitted a brand new
speedo cable which only fixed the twitchyness of the speedo needle .

the thing is ,this car had the very same behaviour with the 1.8 16v engine .
since fitted the 2 litre , all that stayed from the old engine was icv , speedo cable and throttle body . now unless its a fault at throttle potentiometer it has got to be the fokkn speedo cable somehow .
next to come out is the throttle body 8)