82 xfire is idle high

[Phenom]

I took the air cleaner off and put it back on just how its supposed to, all hoses are secure, but I swear thats when it started idling too high, maybe its unrelated, but it idles at 1200 and will not come down. Any suggestions before I take it in...

 

[rbyrne]

AC idle solonoid?? Just throwing out ideas here to narrow down the problem.

 

[Twin_Turbo]

forgot to hook up the Thermac vac switch hose to the throttle body (hose runs fron drivers side TB outer port to the air cleaner base - underside, into he themac vac switch, then switch runs to the thermac valve o the snorkel)

 

[Phenom]

yes

Its all hooked up, Where is the iac and the ac idle solenoid at anyway, I have read everywhere that its probably a vacuum leak.
There is a valve inside the aircleaner that has alot of carbon, it seems to click when i turn the engine off.

 

[Twin_Turbo]

sre you certain the linkage is not binding under the aircleaner beacuse of something in the way there??

 

[Phenom]

hmmm... I dont think so, but I'll check.

 

[Twin_Turbo]

also check if the cruise control servo or linkage isn't making the stuff hang so that the plates won't close properly.

 

[Phenom]

That vac switch in the air cleaner is clicking back into position when i shut the engine off, I dont remeber it doing that, and if I restart immediatly, it idles correctly for a minute, that seems suspect, maybe ill try replacing that switch, whats the exact name for it?

 

[Twin_Turbo]

The thermac switch switches vacuum to the servo for the snorkel flapper. There's always vacuum on the switch, not on the flapper.

The fact that it idles properly for a minute could be open loop. That means that during closed loop there's an idle controlproblem.

During startup (open loop) idle should be around 1000Rpm and it shoulddrop when the engine is warmed up.

 

[Phenom]

so that the plates won't close properly.

Which plates?m an idiot, but Im learning alot here.

 

[Twin_Turbo]

throttle plates, the things that control throttle

 

[Phenom]

The thermac switch switches vacuum to the servo for the snorkel flapper. There's always vacuum on the switch, not on the flapper.

The fact that it idles properly for a minute could be open loop. That means that during closed loop there's an idle controlproblem.

During startup (open loop) idle should be around 1000Rpm and it shoulddrop when the engine is warmed up.

Ahhh. there is a vacuum on the hose going to the snorkel, so you are saying there shouldnt, it is holding that flapper closed all the time too i think.

 

[Twin_Turbo]

No, there's a vac hose from the throttle body port to the switch (the little block under the aircleaner base, has 2 ports on it) and then one from the switch to the flapper servo.

Something like this:

 

[Phenom]

throttle plates, the things that control throttle

No they close properly as far as I can tell, the TB is dirty where it seats the air cleaner, is there supposed to be an airtight seal between the air cleaner and the TB's?

 

[Phenom]

No, there's a vac hose from the throttle body port to the switch (the little block under the aircleaner base, has 2 ports on it) and then one from the switch to the flapper servo.

Something like this:

Great illustration, when is that damper supposed to open back up, I pull the hose off and plug it but there is no effect on the idle.
Also the temp sensor, how can I eleiminate that a the culprit.

 

[Twin_Turbo]

the seal is supposed to be dirt & dust tight. The TB's have gaskets on top of them to seal to the aircleaner. If they are missing unfiltered air will go through there but it won't give a high idle.

High idle is caused by a problem that occurs at (misadjusted minimum air, IAC control problem - can be ECM problem due to one of many possible reasons) or after the throttle plates (vac leak)

 

[Twin_Turbo]

temp sensor? you mean the CTS 9coolant temp sender) in front of the manifold (often the cause for too rich mixtures or idle problems) or the temperature controlled vacuum switch ?

The flapper should ONLY be open if it's cold (engine compartment air). the switch has a bi-metal in it that opens the vacuum switch when cold and closes it when hot.

 

[Phenom]

OK, the it appears to be working correctly, the temperature controlled vacuum switch was what I was referring to, what about bypassing it.

 

[Twin_Turbo]

leave it connected, it isn't the source of your problem if it's connected.

Is the check engine light illuminated?

 

[Phenom]

No the light isnt illuminated, I appreciate your help by the way,