Strange behaviour...

[Julio Bro!]

Hi:

Although idle isn't jumping or hunting, when I step on the brakes it drops 50rpm, which means it goes to 700rpms while my foot is on the brake pedal. If I release, it goes back to 750rpms.

The exact thing also happens when I shift into reverse, now that's strange.

Suggestions?

[pmkls2]

sounds relatively normal to me.....

[Julio Bro!]

That meaning this also happens to you?

Well, this didn't happen to my car, it's a November 2004 problem.

[pmkls2]

well, my car is a standard, but brake pedal movement does momentarily affect idle on most vehicles because of the change in engine vaccum. Could you give a little more info, like model year and is it stick or auto etc...........

[Julio Bro!]

I have 1993 240SX SE with manual transmission and no ABS.

This is not momentary, you step on the brake and 700rpms are constant. I understand this happening because of the vacuum line, which I will check. But why this also happens when I shift to reverse?

[pmkls2]

Well, I'd like to look into that more actually. My car is pretty much the same as yours except it is a '90 so I will watch and see if it behaves the same. Honestly I wouldnt worry too much if this is all that the car is doing right now, but still I'd like to find an answer for ya.