Use to idle around 850 RPM, but recently dropped to about 400 RPM?

MITCH318

MEMBER
1993 DODGE DAKOTA
V8
4WD
AUTOMATIC
75,000 MILES

My truck use to idle around 850 rpm, but recently dropped to about 400 rpm. Nothing has been done to change the idle speed or anything that would affect it. Some days it will idle normally, but the next day it is back to 400 rpm. I have to watch at traffic lights that it does not stall, which it has done. The truck is used on a farm and encounters a lot of dust and mud if that makes a difference. Any advise would be greatly appreciated.

Saturday, December 8th, 2007 AT 2:22 PM

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

One of the contributing factors for this idle issue could be a dirty idle air control valve.
Over time when you have dirt and debris built up inside the valve it will impact the way the engine idles.
The idle air control valve is located on the throttle body (see diagrams below).

As you mentioned the truck is used on farm duties which makes it a good possibility of having dirty components.

Both the throttle body and the idle air control valve can be cleaned to restore performance.

Here are a couple of helpful guides on cleaning these components:

https://www.2carpros.com/articles/idle-air-control-valve-service
https://www.2carpros.com/articles/throttle-actuator-service

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

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