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Old 02-18-2005, 07:19 PM   #1
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Default Start Up High Idle

Every time I start up my 1994 SE the idle goes up to around 2500 RPMs and then drops down to its normal idle. It does this whether warm or cold. First, do you consider 2500 RPMs to be normal or too high and second, what part controls this?
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Old 02-18-2005, 08:26 PM   #2
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Default Re: Start Up High Idle

Quote:
Originally Posted by kennyz
, what part controls this?
Powertrain Control Module (PCM) can adjust idle speed by controlling the air that bypasses the throttle plate. This is done by a little stepping motor that opens and closes a pintle valve - the assembly is called the IAC valve- Idle Air Control. But the PCM takes other information in consideration, like temperature of the engine coolant and temperature of the incoming air among other things.
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Old 02-18-2005, 08:28 PM   #3
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Mine is routinly above 1500. It has settled down some recently after some AFC tuning, between 1100 and 1500 when it'* warm, but if it gets any lower it likes to die.
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Old 02-18-2005, 08:33 PM   #4
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Quote:
Originally Posted by jwikoff99
Mine is routinly above 1500. It has settled down some recently after some AFC tuning, between 1100 and 1500 when it'* warm, but if it gets any lower it likes to die.
1500 steps????? My scan tool says 37 steps with the headlights on?
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Old 02-18-2005, 08:34 PM   #5
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That'* RPM...
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Old 02-18-2005, 10:28 PM   #6
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Try doing the TPS learn. Key On, Engine off for 30 seconds. Sounds normal though.
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Old 02-18-2005, 11:08 PM   #7
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I've tried doing that. Leaving the ignition on for up to two minutes, then turning it off then starting the engine. Should I start the engine without turning it off first?
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Old 02-21-2005, 05:16 AM   #8
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Quote:
Originally Posted by jr's3800
This to me looks pretty normal for a Vin L 3800.... Does it drop to idle fairly quick?
Yes, it always drops right down. Idles around 800 RPMs.
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Old 02-21-2005, 06:56 PM   #9
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Thanks for all the replies. Sounds like the general consensus is that this is normal. I`ll try disconnecting the battery just to see if it changes anything. I guess at 174,000 miles I should probably just be happy that it still runs.
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