Odd idle speeds, need help

P

Primer66

Member

Aug 22, 2021

9

3

13

USA

Oct 5, 2021

#1

• Oct 5, 2021

• #1

Hey everyone,
I have a '66 with a 289 V8. When I'm in park it idles at around 600rpm, but when I give the pedal a couple taps it'll bump up and stay at 900rpm. This also happens when I'm in gear and slowing coasting a parking lot. Any ideas on what causes this?

 

wicked93gs

15 Year Member

Sep 30, 2006

1,198

228

93

Nashville TN

Oct 7, 2021

#2

• Oct 7, 2021

• #2

My first guess would be a sticking spring or throttle plate. ATX or MTX?

 

KRUISR

10 Year Member

Apr 16, 2015

1,819

927

143

Oct 8, 2021

#3

• Oct 8, 2021

• #3

Carb or EFI?

 

7991LXnSHO

wanna catch the space herp

10 Year Member

Sep 1, 2010

7,387

2,745

194

Kearney, NE

Oct 8, 2021

#4

• Oct 8, 2021

• #4

If it’s the carb, check that the choke is opening fully and the high idle cam is not getting engaged after warm up.