Just cleaned my throttle body, and installed a used but good AMM.

I've always had a wobbly idle at a cold start up, but it evens out after the motor is warm.

Now at a cold start up, the RPMs gradually increase to around 2K, instead of bobbing around 1K until
the motor warms up, runs like a champ after its warm.

I used card cleaner to clean my IAC out, made sure it was dry and installed it, could this have damaged it?

My thoughts are a bad Oxygen sensor or coolant temp sensor, any thoughts?

Thanks for all the help!

It is not unusual for the idle speed to be too high after a throttle body cleaning.

Over time the build up in the throttle body chokes off the air flow at idle causing a drop in the idle speed. Some people (including uneducated mechanics)solve this problem by adjusting the throttle plate open a little more. As a result the correct idle speed is restored.

Fast forward to a cleaning of the throttle body. Once the buildup is removed the throttle plate is open more than it should be and the resulting idle speed is too high.

I would check that the plate doesn't need to be adjusted (along with the associated switch). The procedure is outlined in the FAQ's.

Good luck,
Randy

Skiman,


An oxygen sensor will not affect the engine at all when starting or shortly after.

A coolant temperature sensor is likely not the problem. In fact, sensor problems are completely off the table. You need to look for mechanical problems like broken hoses or old gaskets on the intake manifold. Reset the throttle switch and plate according to the documents on kjet.org.


Goatman

Did you make sure the 'butterfly' in the IAC was moving freely after cleaning? I usually jump the connector with 12V to see how easily this Butterfly flips open and closed. After doing a Throttlebody. IAC and Intake Bellows Cleaning, I had a high idle when cold for about three days. Not sure if it was the gathering of Fumes from the Carb cleaner or what. It settled down and was fine after that.


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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html

What year?
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'86 sedan with 450,000 miles on the original engine and automatic transmission

Its a 1985

Maybe there is still a little build up of carb cleaner that needs to blow out.

I let it dry for around 30 mins but it still smelled pretty heavily of carb cleaner when I
installed it. Perhaps there is some residual cleaner in there that needs to work its way out?

Do IAC's need frequent replacing?

As far as checking for leaks and such, just have carb cleaner handy and spray the intake
hose and other areas and the idle should jump, correct?

If checking for leaks with Carb Cleaner, The idle will probably drop when/if it is sprayed on a leak. Now if youy use Starter Fluid (Ether) then idle will jumpup higher.
Just for reference, I have my original IAC with 300K + miles on my '89.

Any hoses you took off while doing this cleaning, Make sure they are back in place and seated nicely.
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'75 Jeep CJ5 345Hp ChevyPwrd, two motorcycles, '85 Pickup: The '89 Volvo is the newest vehicle I own. it wasn't Volvos safety , it was Longevity that sold me http://home.lyse.net/brox/TonyPage4.html

Great thanks for the help everyone