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
I was advised the other day NOT to unplug my airpump unless I want a dodgy idle.
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.
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.
from what ive heard itwont
jsut unplug it not that hard connection right there
reset ECU and go from there see what happens
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...
When you say idle valve, do you mean the little screw under the inlet elbow?
Jon
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
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.
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
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.
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??
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
plus why would the dle stay high or go back up high when it gets really hot?
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
well looks like im going to take throttle body off tonight and give it a good clean check round there
and clean so hopefully that should work
Do the FD\'s have a BAC valve like the FC\'s ? - if so this also affects Idle and can be cleaned. I believe it has something to do with load related air flow.
http://www.1300cc.com/howto/how2/bac.htm (http://www.1300cc.com/howto/how2/bac.htm)
Unmetered air intake is another cause of erratic idle - try spraying some hydrocarbons/alcohol (degreaser spray) around the gaskets for the throttle body and UIM/LIM and see if the revs suddenly pick up - if they do you\'ve got a leak.
first ive heard of this BACK valve where on the FD is it? to me jus tlooks liek the idle valve which already looked into
also thanx for the headups up on the leak thing
Grab a multimeter and check the voltage on the TPS, its an easy thing to do and does not involve jepardising gasket seals with constant removal and replacement........................................ and they DO go out of tolerance and cause hunting aswell as irratic idle issues, so well worth a look.
TPS check and double checked and perfect within range
my idle doesnt hunt it just hold itself high
Cool and double cool, an unmetered leak will also cause irratic idle not a constant high, looks like the answers been on the thread all along. investigate your idle screw.
ok theres three screws that could be all idle screws imo and all three at note touch the throttle stops
and the throttle flaps are cloing 100% as i took the throttle body off last night gave it a good clean and check and def not that