Low idle when temps are COLD??

[grasscutter96]

1984 GL 4X4

 

Is it possible to have a low idle (where car will stall), when its below freezing?

But then, when temps are hot during summer, the idle is high (like 2K +)??

 

Is there a switch or valve or something that would hold the throttle open when engine compartment or outside temps are hot? Would that same valve or switch then not function in the freezing temps?

 

Seems like I remember a thread that discussed a sensor that affected the throttle / rpm, based on engine compartment temps??

 

What I've done so far:

1984 GL 4x4. 77K. Rebuilt carb last year. (twice, due to major corrosion- car sat for 19yrs before I bought it.)

Put 12K on it since carb rebuild, runs great, starts great and MPG is good. So I can't point to the carb that would explain the weird idle issue.

 

Any thoughts?

Edited December 14, 2010 by grasscutter96

[MilesFox]

Stuck idle air control (IAC) valve (works like a choke) or bad engine/coolant temp sensor (CTS) which helps to control the IAC

 

Search these terms to see what you find, then open your hood and try some of the suggestions.

 

whops just noticed your year. There are some electricals going to the carburetor to maintainidle with solenoids or to pull off the choke, and to cut off fuel to the bowl when the car is turned off.

 

It is possible you may have a bad intake manifold gasket causing a vacuum leak. I have an 86 ea82 with carb, and rebuilding the carb did nothing until i replaced the intake manifold gaskets.

 

I have also had older subarus with the carter/weber 1bbl carb that would get loose at the base because one of the screws would back out repeatedly, causing a carb base gasket leak

Edited December 14, 2010 by MilesFox

[grasscutter96]

Intake leaks should show up on the plugs as a very very light tan almost white electrode. My plugs (havent checked recently), were a nice dark brown. I'll check them again. Did put new OEM Subaru carb base gasket on, with just a touch of RTV around base of each carb stud.

 

Also sprayed carb cleaner around carb base and on intake area going to ea head. No change in RPM.

 

Intake leaks wouldn't explain the very high idle when I drive it during normal summer temps.

 

** Extra info on high idle during summer: When its 80, 90, etc. and the idle is around 2K, I can put my foot under the accelerator pedal and pull it up a little bit and the idle speed drops to normal.

 

So I check throttle cable for binding. All ok.

 

Checked throttle / carb linkage free play @ the carb. All ok.

 

Disconnected throttle cable and checked accelerator pedal for binding. All ok.