Why is my car acting cold natured?

Check your IAC, air filter, etc...

http://www.muscularmustangs.com/iac.html

Good luck!

Check for vaccume leaks. Also set TPS voltage to right under a volt, .99, also clean out the TB and IAC.

Also check for codes. If your coolant temp sensor is not reading right it could be sending the wrong signal to the computer at start up.

Dump the codes and see what the computer says is wrong…

Here's the link to dump the computer codes with only a jumper wire or paper clip and the check engine light, or test light or voltmeter. I’ve used it for years, and it works great.

See http://www.troublecodes.net/Ford/
OR
See http://www.dalidesign.com/hbook/eectest.html for more descriptive help
OR
See http://www.mustangworks.com/article...c-iv_codes.html

IF your car is an 88 stang, you'll have to use the test lamp or voltmeter method. There is no functional check engine light on the 88's except possibly the Cali Mass Air cars.

Codes have different answers if the engine is running from the answers that it has when the engine isn't running. It helps a lot to know if you had the engine running when you ran the test.

Trouble codes are either 2 digit or 3 digit, there are no cars that use both 2 digit codes and 3 digit codes.

For those who are intimidated by all the wires & connections, see http://www.actron.com/product_detail.php?pid=16153 for what a typical hand scanner looks like. Normal retail price is about $30 or so at AutoZone or Walmart .

my car does the same thing, i tried 3 iac in the past month, cleaned out tb and air filter. I havent tried tps yet. Do you have a Mech. water guage? I have one and tapped it into the stock location. It might be causing it b/c comp is no longer getting readings.

I cleaned my IAC just because I had nothing else to do, and ever since then my car doesn't run right. If it sits for 7+ hour, when I start it up it will idle at 1.5k for about 30 seconds. I've even put a new IAC on it, and it didn't change anything. So I wouldn't advise to clean the IAC.

Cleaning IAC fixed my idle issues.

I HAVE however had similar issues with it having an odd (floating) idle at startup after the car has sat for a little while. It all corrects itself after a minute or so and runs VERY nice and smooth.