92 - Unstable/Erratic Idle

[Awdtsi42o]

Hey guys, Happy New Year!

I live in New England and recently the temperatures have gotten pretty cold. In the past few days I have noticed that after the truck has warmed up, the idle is very unstable. The idle goes down a little below 1000 RPM, where it usually stays when idling properly.

However lately after the vehicle is warmed up, while idling the RPMs go from 1000 then climbs to 2000 RPM, then drops back down to 1000, back up to 2000, drops back to 1000 over and over. This happens whenever I am in the stopped position, after the problem starts happening it does not go away until I turn the car off.

I am not sure how this car is set up but I know in the past I have encountered problems with idle control valves, and they have given similar symptoms when they are malfunctioning. I am not sure what type of system this vehicle uses to control the idle.

I was looking for any information or guidance on where to start to resolve this issue.

Any suggestions would be greatly appreciated.

Thank you for your time,

Will be checking back throughout the day,

Erick

 

[jimwww]

Check for cracks/breaks

Check for cracks/breaks in the hose (plastic) from the engine to the air filter - they are prone to breaking and if there is air getting in - it will not run right (happened to mine)

 

[Awdtsi42o]

Thank you very much for the quick reply,

Would the issue your talking about cause the issue to happen only when it is extremely cold out after the car has warmed up?

What I am trying to say is the truck does not do it all the time, only does it when it is really cold out after the truck is warmed up.

On mild days it does not do it at all, however it might just be a coincedence.

I am going to look into it and I will let you know what I find.

Thanks again for the quick reply,

Erick

 

[jimwww]

idle control valve

You might want to check, most vehicles have one. Clean your fuel injectors and change your fuel filter, your vehicle is trying to get more fuel at a certain point in temperature.