Idle problems

[filh]

I know it has often been discussed here , I've got Idle problems .
The engine revs up and down from idle to about 2700rpm.
First of all , I swap my broken engine with a second hand one .
All periphericals are mine, from former engine .
I made a research here and found that the problem comes very often with cooling system .
So I check the cooling circuit , but found nothing .
Here's a list of parts I change to try correcting that problem :

-Intake air sensor
-water temp sensor
-start injector start time
-Vacuum Sensor
-VSV for idle up
Injectors , Throttle(including TPS) , and air colllector are same as the engine I broke , as I had no problem !

When idle move from low to high revs(+/- 2700rpm) I removed the Vacuum sensor hose and the idle was stablt . As soon as I got the hose on , the moving idle is back .
I also swapped 3 or 4 distributor , whithout success .
Any idea where to look at ??
I'm really desesperate and in a hurry for my next rally

Filh

[tolisspi]

its normal when start the engine to be 2700revs and after down

[filh]

I don't speak about cold start but engine at normal temperature ( 80 c°) of course!

[gtsr54321]

the valve under the throttlebody maybe?

whenever someone asks about idle problems on other forums people always say it has to do something with that valve.

[jondee86]

Try winding out the idle air screw (the one down the hole on the side
of the throttle body).

Oh, and the other thing that you should try, is blocking off the idle air
bypass port in front of the throttle butterfly. While the engine is running
just block it off with your finger, and see if the idle stabilises. If it does
you need to strip and clean/replace the thermostatic idle-up that bolts
to the underside of the throttle body (the part that the two small water
hoses connect to).

Cheers... jondee86

[Ivan141]

Those two small water hoses also get clogged up sometimes...

[filh]

thanks for helping . I read a lot on Club4age forum , and the same part is often pointing out : the AAV (I guess Additional Air Valve) .
I think it's located under throttle body ? How do you clean it ? Isn't it a sealed one?
About the two little water hose , there should be coolant in if not clogged ?
And last questions often discussed : As it's an other engine , I had to fill the coolant system , but it seems that a bleeding is needed ! I read several way of doing it , what's yours ?
Thanks again for spending time answering .
Next rally season begin in two weeks , and I'm nowhere now
Phil

[The Doctor]

if i bleed my system, i start and run it with the cap off, and the heater turned on. Let it warm up untill the thermostat opens and keep an eye on the level in the rad.

[Sanity Clause]

Have a look at this thread... http://www.aeu86.org/viewtopic/heater-pi...highlight=

Note my comment regarding the supply of hot water to the Auxiliary Air Valve. You may have a blocked water pipe.
However, if hot water is circulating through the AAV, it's possible that the valve [thermostat] no longer works.

To check it, remove your throttle body, and unbolt the AAV.



The AAV [the bit with the pipes coming out of it] can be seen screwed to the side of the TB in the above pic.






Put the AAV in some hot water to see if the valve closes.
If it doesn't, replace the AAV.

HTH

[filh]

Thanks a lot , I just remove the throttle body and will check tomorrow , to see if the AAV work .
Phil