Hi, have 99 Camry 4 Cyl. 5 Speed Man. Been having some problems lately. Car won't start cold. Have to keep foot on the pedal until it engine reaches operating temp. If I start again when engine is warm, it idles high. I've cleaned the small vent leading to the IAC valve on the throttle body. I also read the ohms on the IAC valve. Both negative terminals read between 20-21 ohms. Does anyone else have any ideas for me to try. I love this car. It has 116K miles and don't want to get rid of it. Please help!

 

Did you spray cleaner into the vent when the engine was running. Use a cleaner safe for plastics. Don't use brake cleaner.

Sometimes the coolant temp sensor for the computer goes bad and causes these kind of issue. This sensor is located on the water output housing on the cylinder head. It has 2 wires running to it.

The AutoZone website should have some info on this.

The IAC valve has a small motor inside powered by 12V.

The test is to apply 12V to the center terminal of the plug and negative to the one of the outside terminals. This will move the valve to one side of the stop. Apply negative power to the other outside terminal and the valve will move to the other stop.

You need to remove the valve from the throttle body to view the inside and real valve.

But first try re-cleaning the IAC valve and test the coolant temp sensor.

 

Hey Joey,

Thanks for your reply. I appreciate it very much. I did check the Coolant Sensor (ECT). I took an ohm reading of about 2300 Ohms at approximately 80 degrees ambient temperature. I turned on the engine and brought it up to operating temperature. I took another reading on the ECT terminals and read approximately 350 Ohms. I have also cleaned the IAC opening inside the throttle body. I may have to remove it as you suggested but it looks daunting. Are there any videos online showing how to remove the throttle body? Also, what do you think causes the increase in RPMS when the engine is running and already warm?

Thanks again!

 

Book states coolant temps sensor should be 290 to 354 ohms at 176F.

IAC valve resistance between center terminal and each of the outer terminals should be:
17.0-24.5 ohm engine cold
21.5-28.5 ohm engine hot

To test the IAC valve, find a small plastic box inside the engine compartment labeled "Diagnostic." Might be mounted on one of the strut towers.

With engine hot, trans in neutral. Connect TE1 and E1 terminals with electrical wire. RPM should increase to 900-1300 RPM and after a few minutes return to normal idle speed.

The link below has some info on cleaning the IAC valve. Try this first.

http://www.toyotanation.com/forum/sh...d.php?t=158097

Don't get rid of the car, this issues are not uncommon. Parts are still available, etc.

My also review past posts on IAC valve issues at the Toyotanation site using their search function.

 

I actually did the IAC test on the terminal as you indicated on your E-mail by shorting TE1 and E1. The rpm did not increase. I think I may have to remove the IAC valve and then clean it real good. I'm just hesitant cause it looks pretty daunting to take the throttle body off. Do you have links to any site that may have videos or step by step instructions on how to remove the throttle body?

I absolutely love this and I'm not going to get rid of it. I get 38 miles to the gallon and over 600 miles to a tank of gas. With the price of gas these days, I'm holding on to this puppy.

Thank you!

 

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