# Start stop immediately(99 Crown Vic.)

**URL:** <https://community.cartalk.com/t/start-stop-immediately-99-crown-vic/4510>\
**Category:** Maintenance/Repairs\
**Created:** [September 12, 2007, 5:26pm UTC](https://community.cartalk.com/t/start-stop-immediately-99-crown-vic/4510 "2007-09-12T17:26:17Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Solomon](https://avatars.discourse-cdn.com/v4/letter/s/b4bc9f/32.png) [@Solomon](https://community.cartalk.com/u/Solomon)\
**Post date:** [September 12, 2007, 5:26pm UTC](https://community.cartalk.com/t/start-stop-immediately-99-crown-vic/4510/1 "2007-09-12T17:26:17Z")

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Hi.My 99 CrownVic. Starts fine but will die immediately.It will run slightly rough with a little gas.Yesterday morning it ran a little rough for a minute but was fine. Checked everything fluidwise and looked fine.Thanks

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**Author:** ![Beadsandbeads](https://avatars.discourse-cdn.com/v4/letter/b/c57346/32.png) [@Beadsandbeads](https://community.cartalk.com/u/Beadsandbeads)\
**Post date:** [September 12, 2007, 7:34pm UTC](https://community.cartalk.com/t/start-stop-immediately-99-crown-vic/4510/2 "2007-09-12T19:34:24Z")

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The most common cause of this behavoir is a worn-out IAC (idle air control) valve. The PCM controls idle speed with the IAC valve o modulating the air allowed into the intake manifold. If you can get it to run with just a tiny bit of pressure on the gas pedal, it is probably the IAC. You might also get it to work for a while by tapping on it lightly. I would estimate about $100 for the part. It is easy to install. You can find some pictures at [www.crownvic.net](http://www.crownvic.net).