Low engine idle?

Hi,

When you turn the A/C on, the computer compensates for the added load by increasing the idle speed. So, we know the idle air control circuit is working.

My next suspect is you may have an engine vacuum leak. I would start by checking if anything is damaged, disconnected, or loose.

Here is a link that explains how to check:

If I had to guess, this is what I suspect is the issue.

Here is another link that describes common symptoms related to the:

https://www.2carpros.com/articles/7-common-symptoms-of-a-vacuum-leak-in-your-car-how-to

Let me know what you find.

Take care,

Joe

Thank you for your reply. I have inspected myself for vacuum leaks. I will check again with a mechanic soon.

Yesterday I disconnected the Stop light fuse. And shifted gear to drive. (So, brake lights won't turn on when i hold the brake). RPMs didn't go low. Do you think there will be other reason other than vacuum leaks?

I checked battery voltage with alternator on and off, it's all good.

Hi,

Yes, there could be an issue with the idle speed control circuit. The standard idle speed:
is between 720 to 820 rpms in neutral or park. Once in gear, that will lessen. This is why I'm questioning a vacuum leak. You really aren't far out of what I would consider normal and the rough idle is often indicative of a vacuum leak.

Let me know.

Joe

Let me know if I can help or if you have other questions.