Idle adjustment

Reply Subscribe

Thread Tools

Search this Thread

Sep 2, 2023 | 01:34 PM

cullynhaas

Thread Starter

4wd Low

Joined: Sep 2023

Posts: 13

Likes: 0

Idle adjustment

I have a 1981 ford f100, my idle seems to be running high at 1800 and shifting into first it’s jumpy. How do i adjust it lower and what is the recommended idle speed?

Sep 2, 2023 | 02:00 PM

Max Capacity

Lead Driver

Joined: Jun 2013

Posts: 5,669

Likes: 1,160

From: Tolland, CT

Have you sprayed the throttle cable with penetrating fluid. It may help.

There should be an adjusting screw on the lever on the carb that moves when you step on the pedal. Adjust that screw.

What engine do you have ? 700rpm or so should be fine.

Sep 2, 2023 | 02:31 PM

Franklin2

Moderator

Joined: Jan 2001

Posts: 56,997

Likes: 2,742

From: Virginia

Quote:

Originally Posted by cullynhaas

I have a 1981 ford f100, my idle seems to be running high at 1800 and shifting into first it’s jumpy. How do i adjust it lower and what is the recommended idle speed?

When you first start it cold it should idle fast. If it's a summer day after it runs for a minute or two you should be able to pat the gas pedal swiftly and be able to kick the idle down. If it keeps idling fast, go out and take the aircleaner off and look at the top of the carb throat. There should be a metal door on top of the carb. If the engine is warmed up, this door should be standing straight up. If it's partially or almost shut, that is what is causing your high idle. That is the choke.

With the engine off, push the throttle wide open on the carb and while holding the throttle open, take your finger and open the door straight up and down. While holding the door open, slowly let the throttle back shut. Without touching the gas pedal start the engine. If the engine is warm it should start and idle slow. If you touch the throttle and it suddenly idles high again, go out and look at the top of the carb and see if the door has shut again. If it has, your choke has a problem.