# Fast idle

**URL:** <https://community.cartalk.com/t/fast-idle/79984>\
**Category:** Maintenance/Repairs\
**Tags:** mazda\
**Created:** [June 22, 2013, 9:30pm UTC](https://community.cartalk.com/t/fast-idle/79984 "2013-06-22T21:30:51Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![wannaknow](https://avatars.discourse-cdn.com/v4/letter/w/3d9bf3/32.png) [@wannaknow](https://community.cartalk.com/u/wannaknow)\
**Post date:** [June 22, 2013, 9:30pm UTC](https://community.cartalk.com/t/fast-idle/79984/1 "2013-06-22T21:30:51Z")

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owning a mazda B4000 pkup with 110,000 well maintained miles, I have incurred a idle problem. The AC has had Freon added, the Orphis tube cleaned, a new idle adjustment valve installed and now, diagnosed, vacuum leaks repaired and a new vacuum modulator installed.  
With AC on, idle is 11 to 1200 RPM, with it off, about 625, where it should be. A racing engine is not fun at stops. any suggestions?

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**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\
**Post date:** [June 23, 2013, 8:22pm UTC](https://community.cartalk.com/t/fast-idle/79984/2 "2013-06-23T20:22:00Z")

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It really isn’t too far off the specs. Is this an automatic transmission or a manual?

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**Author:** ![knfenimore](https://avatars.discourse-cdn.com/v4/letter/k/9fc348/32.png) [@knfenimore](https://community.cartalk.com/u/knfenimore)\
**Post date:** [June 23, 2013, 11:25pm UTC](https://community.cartalk.com/t/fast-idle/79984/3 "2013-06-23T23:25:26Z")

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If the IAC and the vacuum leaks are fixed, then it’s the ECM driving the IAC. Try disconnecting the battery for 5 minutes and the the ECM will be reset. There is a TSB for high idle, but it was not the exact same problem and its fix was vacuum leaks.