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Old 07-29-2020   #1
S.hafsmo
 
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Default High Coast- / start up idle

I've always had periodic high idle (1500-1800 RPM) while coasting and just after start up. It did improve with the Haibeck chip, but it's still very much present. My throttle body has also been refurbished by Mark. Except of the above mentioned situations, it idles steady around 750 RPM.

Is this normal? Might it be caused by a slow/defective IAC?
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Last edited by S.hafsmo; 07-29-2020 at 12:38 PM.
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Old 07-29-2020   #2
Ccmano
 
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Default Re: High Coast- / start up idle

Normal, especially for 90'. It was an emissions thing.
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Old 07-29-2020   #3
S.hafsmo
 
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Default Re: High Coast- / start up idle

Well that's annoying. I was hoping something was broken.
Thanks, though.
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Old 07-30-2020   #4
Paul Workman
 
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Default Re: High Coast- / start up idle

Quote:
Originally Posted by S.hafsmo View Post
Well that's annoying. I was hoping something was broken.
Thanks, though.
Agreed. Especially annoying should you stall the accidentally stall the motor in stop n go traffic.

Until you can stop and let the idle fall back to normal - about 3 seconds or so - idle will remain high on restart. (Takes some extra attention to technique to avoid it (accidentally stalling). Just a quirk of the 90s, it seems.)
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