When I pull up to an intersection and hit the brakes, the idle drops enough that the car shakes a bit. Its kind of annoying. What do you think the problem is?

 

Try these tests:

 

The car passed all of those tests. No pressure oddities found.

 

This happening a little bit is normal.

However, maybe your idle is set too low, and the amount the idle goes down puts the idle lower than it should be. Just a speculation though... don't just go adjusting idle... get someone else's opinion first.

 

2000 Civic? D16Y7? Do you have an automatic or manual transmission? If you pop the transmission into neutral without pressing the brake, is the idle normal or still low? If you press the brake with the engine in neutral, does the idle speed go down? Does the engine die? How low is the idle speed?

 

'tis merely an auto, and yes. D16y7. I haven't tried putting in neutral, but I would guess the idle would stay normal. When I head out to work in a few, I'll check on that one. When it idles low, it seems to be around 500 or under, which is less than normal for this engine. The engine hasn't died yet, but it seems like it could.

 

You replied too quickly! I was adding more questions as usual. See edited previous post.

 

edited

 

Post the outcome of those additional tests. I guess a key question is whether the transmission must be in Drive and the brake depressed to lower the idle speed. So try the same but with the transmission in neutral. I am trying to figure out whether the problem is with the transmission being in Drive, the brake depressed, or both.

I assume there's no CEL, battery light, or other warning light ON?

 

I was unable to duplicate the problem on the way to work and on the way home this morning. I'm stumped as to why it's intermittent. When I drop into neutral, the rpms stay the same. It has only happened while I was driving, then stopping at an intersection. And no, there is no CEL (CEL works), no battery light, and no other warning lights.