How cold for fast idle?
Thread Starter
Drifting
Joined: Nov 2013
Posts: 1,806
Likes: 258
From: Dublin Ohio
How cold for fast idle?
I know I remember my car idling faster at start up at some time in the past but this summer, even if I haven't started it for a week, it idles at 800 from the get go.
Should I get a higher idle at startup through the summer months?
72 base engine 4 speed stock except for cam from earlier 350. Tcs is hooked up.
Should I get a higher idle at startup through the summer months?
72 base engine 4 speed stock except for cam from earlier 350. Tcs is hooked up.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Unless you live in the desert and are starting the car outside at 3pm in the summer, your choke will engage...at least, partially. So, yes, the car will start with elevated idle RPM from a 'cold' start (if the choke is working properly).
Racer
Joined: May 2011
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From: Dover Delaware
Team Owner
Joined: Sep 2006
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From: Westminster Maryland
Hi Barry,
You mention that the TCS is in operation on your engine.
If the TCS is operating properly I'd think the idle speed would be 300 to 700 rpm higher than the normal 'choke' rpm and would remain at that increased rpm until the engine temperature reaches above 82 degrees…. a "cold engine start".
When you "re- start" the engine and it's WARM enough that the CHOKE DOESN'T set, the TCS should STILL RAISE the rpm briefly.
Also, the TCS should RAISE the rpm, (even on a WARM engine,) when ever the transmission is in 4th gear; but there's a delay of about 20 to 30 seconds (the trans needs to remain in 4th gear) before the rpm rises.
SO, are you seeing a choke rpm situation, or a TCS rpm situation?
Regards,
Alan
You mention that the TCS is in operation on your engine.
If the TCS is operating properly I'd think the idle speed would be 300 to 700 rpm higher than the normal 'choke' rpm and would remain at that increased rpm until the engine temperature reaches above 82 degrees…. a "cold engine start".
When you "re- start" the engine and it's WARM enough that the CHOKE DOESN'T set, the TCS should STILL RAISE the rpm briefly.
Also, the TCS should RAISE the rpm, (even on a WARM engine,) when ever the transmission is in 4th gear; but there's a delay of about 20 to 30 seconds (the trans needs to remain in 4th gear) before the rpm rises.
SO, are you seeing a choke rpm situation, or a TCS rpm situation?
Regards,
Alan
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From: New Or-leens Loo-z-anna
Is it possible that I have the tension too tight on the adjustment cover?
Thanks.
Melting Slicks
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If the car idles smoothly at 800 on a cold start, I myself would not mess with it.
Melting Slicks
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From: Shreveport LA
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When I first start my engine (cold) it idles at 1250 until I "goose" it and it drops down to 900. Once the choke disengages, it drops to 800 (in Park)...in Drive it drops to 650-700 
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Thread Starter
Drifting
Joined: Nov 2013
Posts: 1,806
Likes: 258
From: Dublin Ohio
Thanks for all the replies.
Well, I think I'm starting to remember. I think the car idled higher when I had the TCS bypassed, but nothing like what the fast idle sounds like - so evidently it was just never adjusted to run at fast idle. The guy who built the engine probably had the same thoughts as Pltmgr.
I checked the fast idle screw and screwed it in. Now at cold start I have it around 1350 - what my sticker says - but then it raised up to 1500 for bit and then settled back down to 1250-1300 - like Alan suggested. Tap the pedal, down to 750-800.
I really just wanted to make sure everything works if it has to.
Well, I think I'm starting to remember. I think the car idled higher when I had the TCS bypassed, but nothing like what the fast idle sounds like - so evidently it was just never adjusted to run at fast idle. The guy who built the engine probably had the same thoughts as Pltmgr.
I checked the fast idle screw and screwed it in. Now at cold start I have it around 1350 - what my sticker says - but then it raised up to 1500 for bit and then settled back down to 1250-1300 - like Alan suggested. Tap the pedal, down to 750-800.
I really just wanted to make sure everything works if it has to.