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Lost Initial Cold Start Fast Idle (first time)

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Old Oct 1, 2021 | 07:49 AM
  #1  
Carlos89's Avatar
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From: Miami, FL
Car: 1986 Trans Am
Engine: 5.0 LG4 4BBL
Transmission: T5 5-Speed
Axle/Gears: 3.23
Lost Initial Cold Start Fast Idle (first time)

Morning guys,

Out of the blue, I seem to have lost initial cold start fast idle this morning. I hit the throttle once before start-up as I do every morning, engine started within 3 second as usual, BUT idled immediately at 800 steady instead of the usual 13-1400 it always does when cold.

It crossed my mind to not drive it since it was still dark but I let it idle for 2 min then drove away, perfectly normal the whole 8 mile drive to work. No hesitation, no weird smells or sounds even on the highway.

I had the factory Q-jet rebuilt 2 months ago and after some initial tuning its been solid ever since.

Any initial thoughts before I take a look at it this afternoon?

Thank you everyone.
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Old Oct 3, 2021 | 09:50 AM
  #2  
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Re: Lost Initial Cold Start Fast Idle (first time)

Try a shot of spray silicone lube on the fast idle linkage all over the carb. Hold the throttle open a bit with one hand and work all the links with the other, see if anything binds.

Not rocket science here, it's just a carb.
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Old Oct 4, 2021 | 09:17 AM
  #3  
Carlos89's Avatar
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Joined: Sep 2018
Posts: 170
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From: Miami, FL
Car: 1986 Trans Am
Engine: 5.0 LG4 4BBL
Transmission: T5 5-Speed
Axle/Gears: 3.23
Re: Lost Initial Cold Start Fast Idle (first time)

Originally Posted by sofakingdom
Try a shot of spray silicone lube on the fast idle linkage all over the carb. Hold the throttle open a bit with one hand and work all the links with the other, see if anything binds.

Not rocket science here, it's just a carb.
Man, you won't believe this but when I got home from work that afternoon and took a look with proper lighting, it's exactly what I did when I saw nothing out of ordinary. As you always propose, lets cut through the clutter to find the simplest explanation
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Old Oct 5, 2021 | 06:34 PM
  #4  
sofakingdom's Avatar
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Joined: Sep 2005
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Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Lost Initial Cold Start Fast Idle (first time)

Does the stat have tension?
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Old Oct 6, 2021 | 11:55 AM
  #5  
Carlos89's Avatar
Thread Starter
Member
 
Joined: Sep 2018
Posts: 170
Likes: 42
From: Miami, FL
Car: 1986 Trans Am
Engine: 5.0 LG4 4BBL
Transmission: T5 5-Speed
Axle/Gears: 3.23
Re: Lost Initial Cold Start Fast Idle (first time)

Yes.

Looks like the lube did the trick.
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