Fast idle

CATSUE61

MEMBER
1982 NISSAN TRUCK
4 CYL
2WD
MANUAL
249 MILES

Idle up too high. It runs pretty smooth when I drive it, but when push in on clutch idle goes through the roof and won't idle down. It idles high sort of when going down road have adjusted idle speed but hasn't helped.

Sunday, March 14th, 2021 AT 1:37 PM

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,747 POSTS

Hi,

First, remove the throttle cable to make sure it isn't hanging up. Next, is there anything you can do to lower the idle speed? What screw on the carb was adjusted? Did you remove the concealment plug to access the air/fuel mixture screw? See pic 2

Here are directions for setting the fast idle. I'm adding this simply because I'm not sure what is happening yet. You can check it.

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1982 Nissan-Datsun Truck PL720 2WD L4-2187cc 2.2L SOHC (Z22)
Fast Idle Speed (Off-Vehicle), Adjust
Vehicle Powertrain Management Fuel Delivery and Air Induction Carburetor Adjustments Fast Idle Speed (Off-Vehicle), Adjust
FAST IDLE SPEED (OFF-VEHICLE), ADJUST
Fig. 15 Fast idle adjustment.

see pic 1

1. Place fast idle screw on second step of fast idle cam.
2. Turn fast idle adjusting screw until dimension ``A,'' Fig. 15, is according to specifications.

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One other thought. Have you checked for engine vacuum leaks that can cause idle speed issues? Here is a link that explains how to check.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

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Let me know what you find or if you have other questions.

Take care and God Bless,
Joe

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