what controls idle aswell except idle valve?

[aposegil]

Hello all

except for a idle valve, what else controls the idle depending how hot the engine is? ?

is it that double throttle thing that works off water temp ?

thank you in advance

[Ricco_04]

I was advised the other day NOT to unplug my airpump unless I want a dodgy idle.

[aposegil]

oh ok

but im bit confused how that will affect idle depending how hot the engine is?

also air pump there if you have a CAT otherwise no need for it.

[Ricco_04]

Oh sorry, shouldnt make a difference betwene hot and cold - didnt get that bit into my head! :2Confused

I went full decat the other day and when I asked if it was ok to unplug the air pump I was told yes I can but it will make the car have a bad idle.  I don\'t know why it does, I didnt ask further.

[aposegil]

from what ive heard itwont

jsut unplug it not that hard connection right there

reset ECU and go from there see what happens

[iaint]

Maybe disconnect is different from removal - mine\'s removed and no idle issues  Programmable ECU may make a difference but I guess only because teh stock ECU accounts for the load from the pump belowe 2.5k rpm...

[jonrx7uk]

When you say idle valve, do you mean the little screw under the inlet elbow?

Jon

[aposegil]

nope i mean the actual electrically controled valve that sits on the side of inlet and faces firewall thats has a white plug to it

the idle screw is all the way in

[jonrx7uk]

I dont think the screw should be all the way in? do you have a PFC?

There is a "fast-idle-cam" attached to the throttle body (firewall side) that when water temp reaches a set point (60 deg IIRC) lowers the throttle cable all the way down, lowereing the idle speed.  You can check its working by putting it in boiling water (wax rod inside expands).

Cheers Jon.

[aposegil]

i know what u mean about that wax rod

it does move but how much is it meant to move? also my guess is something is sticking as when its hotter its sticks even more i.e idle is kepted higher

so is there anythign i sould take off clean etc? to make it better?

I think its got something to do with that thing on the side of the throttle body face the firewall

as the americans get rid of it but they call it something else

[nikp]

Yeah - concerned about your comment \'idle screw is all the way in\' - having this screw all the way in will increase the idle speed dramatically.

[royal]

If your idle screw is all the way in wouldn\'t it be compensating for some kind of vac leak? just speculating but just wondered??

[aposegil]

nikp thats a interesting comment u just mention

i didnt put it all the way in but ive just tried it and if u turn it clock wise (outwards) idle raises? so not sure what to say?

nope idle on boost gauge showing 20 which im told is good

plus if i unplug a vac either for dump valve or boost gauge idle goes up even more

[aposegil]

plus why would the dle stay high or go back up high when it gets really hot?

[jonrx7uk]

The fast idle cam does have an adjuster screw.  I would take this off and test it in boiling water.  Page F79 of workshop manual shows you how.

Also , the dashpot (little mushroom thing the throttle cam sits down on when you let off) can become stuck.

Cheers
Jon