1995 Oldsmobile Silhouette Logo
Posted on Jul 17, 2008
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Fast Idle My 1995, 3.8 sometimes idles at 2500 rpm when i shut it off and restart it it will run right for a while and then go back to running fast. It will sometimes not want to start just keep turning over. If I let it turn over about 6 or 7 times it sometimes will start.

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  • Posted on Nov 05, 2008
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Hello two major culprits off this is your TPS sensor wich controls the idle what you need to look at is when you start the car does the Rpm needle stay in a semi fixed position give or take a couple of lines or does it idle erratic it should be at a semi fixed if erratic it probaly is out of range you can test with a ohm meter if not autozone offers free testing on sensors The second problem wich sometimes can not be detected by a scanner and doesnt always set a hard code is your IAC motor IDLE AIR CONTROL VALVE wich is inserted internal into your throttle body on the end of this has a top shaped piece wich plugs a bore hole internaly inside if this is built up with carbon or varnish it binds internally causing higher idles, lower idles ,stalling, nostarts ,hesitation,rough idle, etc this mounts with usually to torx shaped screws also can be tested with scanner but dont rule this one out it can retract and extend register fine to the computer but bind internal with out ever setting a code goodluck please rate thanks

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The problem here is most likely the thorttle position sensor or TPS what is occuring is the snsor is telling the motor that it is still running at speed and not idle. the hard start wouold appear to be a flooded condition cause by the tps being open. Hope this helps

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when the idle surges, that means.
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http://jeepdied.com/Misfire101.html

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