Idle speed continues to climb

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

84K30

Full Access Member
Joined
Jul 14, 2019
Posts
160
Reaction score
69
Location
SWPA
First Name
Eric
Truck Year
1984
Truck Model
K30
Engine Size
454
I’ve been messing with the high idle speed on my K30 for a few days now that it’s getting cooler out.

Engine is a 454 and factory carb has been replaced with a Edelbrock 1406.

A while back, Craig85 provides me with the correct idle speeds for my configuration: 700 and 1900 (high)

It seems as though my idle speed fluctuates a bit, usually between 650 and 750, but it runs well enough.

The high idle speed is another story. If I set it at 1900 it will slowly climb to 22/2300 before getting to operating temp. At that point I have to “blip” the throttle to make the engine drop to normal idle.

Is this the manner in which a high idle is supposed to work or should it stay where I set it? Also, should the engine speed drop on its own once it’s to temp?

Thanks,
Eric
 

Wumbo

Full Access Member
Joined
Dec 12, 2018
Posts
1,084
Reaction score
3,997
Location
Illinois
First Name
Rob
Truck Year
1986
Truck Model
C20
Engine Size
454
Engine speed will increase as it warms up, and yes, you need to tap the throttle to get it off high idle.
 

84K30

Full Access Member
Joined
Jul 14, 2019
Posts
160
Reaction score
69
Location
SWPA
First Name
Eric
Truck Year
1984
Truck Model
K30
Engine Size
454
Thanks for the reply. Should I set the “low end” or “top end” of the high idle speed at 1900? Meaning should it be at 1900 immediately upon startup and let it climb to whatever or should I set it where it needs to be to have it max out at 1900?
 

Wumbo

Full Access Member
Joined
Dec 12, 2018
Posts
1,084
Reaction score
3,997
Location
Illinois
First Name
Rob
Truck Year
1986
Truck Model
C20
Engine Size
454
Personally, I set mine a bit lower. I like mine 1300-1400 at initial start up, and it climbs a couple hundred as it warms up. It's not going to affect much except fuel consumption.
 

84K30

Full Access Member
Joined
Jul 14, 2019
Posts
160
Reaction score
69
Location
SWPA
First Name
Eric
Truck Year
1984
Truck Model
K30
Engine Size
454
Noted. Thanks again for sharing your wisdom.
 

Wumbo

Full Access Member
Joined
Dec 12, 2018
Posts
1,084
Reaction score
3,997
Location
Illinois
First Name
Rob
Truck Year
1986
Truck Model
C20
Engine Size
454
:cheers:
 

potent rodent

Full Access Member
Joined
Mar 22, 2020
Posts
195
Reaction score
112
Location
indiana
First Name
butch
Truck Year
86 and 78
Truck Model
1500
Engine Size
350 and 305
like stated above 1500 is all u want on hi idle, and it takes very little turning of the fast idle screw to get there
 

Big Chip

Full Access Member
Joined
Oct 19, 2017
Posts
4,656
Reaction score
6,734
Location
Michigan
First Name
Kevin
Truck Year
1979
Truck Model
C35
Engine Size
454
The CFM on a 1406 may be a little low for a 454. Does it drive ok?
 

Latest posts

Forum statistics

Threads
44,163
Posts
950,682
Members
36,276
Latest member
2manysquares2care
Top