Engine idling too high?

JROB71

MEMBER
1971 CHEVROLET CAMARO
5.3L
V8
2WD
AUTOMATIC
8,000 MILES

I recently LS swapped my car listed above and for some reason it idles high, I went through the fuel, checked spark. As soon as I let go of the brakes it wants to take off. I don't know what else to look for.

Saturday, January 18th, 2025 AT 11:31 AM

10 Replies

JACOBANDNICKOLAS

MECHANIC
110,055 POSTS

Hi,

When you say you swapped it, do you mean the engine was changed? Is it still carburated? If so, there should be a curb idle adjustment via the throttle control solenoid.

Let me know what you are working with.

Joe

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Saturday, January 18th, 2025 AT 7:11 PM

JROB71

MEMBER
6 POSTS

I LS swapped it 5.3.

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Saturday, January 18th, 2025 AT 7:12 PM

KEN L

MASTER CERTIFIED MECHANIC
50,119 POSTS

Is it driven by wire, or does it have a throttle cable? Please go over this guide:

https://www.2carpros.com/articles/engine-idles-too-high

Please go over this guide and get back to us.

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Tuesday, January 21st, 2025 AT 9:32 AM

JROB71

MEMBER
6 POSTS

Throttle cable.

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Tuesday, January 21st, 2025 AT 10:52 AM

KEN L

MASTER CERTIFIED MECHANIC
50,119 POSTS

Okay, try to start the engine without the cable just the return spring. Also, Is the IAC plugged in and working? Is there a way you can pull codes?

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Wednesday, January 22nd, 2025 AT 8:38 AM

JROB71

MEMBER
6 POSTS

I had no code, and yes IAC works. I'm thinking it's the cheap throttle body.

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Wednesday, January 22nd, 2025 AT 8:44 AM

KEN L

MASTER CERTIFIED MECHANIC
50,119 POSTS

Yep, that will do it. Does this engine have an EGR valve? If so it can be stuck open. I would remove it and use this video to test it.

https://www.youtube.com/watch?v=DqUCbbKdWf4

Let us know what you find.

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Thursday, January 23rd, 2025 AT 9:21 AM

JROB71