At idle, i can press the brake pedal and cause some sort of vaccum issue which causes the idle to jump and down +- 800. Any ideas on this one? No codes have been thrown or anything.

 

could have a leak somehow in your brake booster that opens when the brakes are pressed.

 

It sounds like an issue with the brake booster, such as a poor connection robbing electrical power. Check the connections (grounds), but otherwise I don't believe there's a realtion between the two.

Any problems with ABS?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GSpeedR &raquo;</TD></TR><TR><TD CLASS="quote">It sounds like an issue with the brake booster, such as a poor connection robbing electrical power. Check the connections (grounds), but otherwise I don't believe there's a realtion between the two.

Any problems with ABS? </TD></TR></TABLE>

Hang on, are you under the impression that the brake booster is something electrical???? hate to rain on your parade but its not. u cud mean the brake lights, but this could never cause the idle to fluctuate...

Get a piece of pipe and hold one end to your ear and hold the other end around the brake booster, probing for leaks(u will hear it quite well if its as bad as u say it is) while a friend holds down the pedal with the engine running. is the pedal harder to push than usual? that would also signify a leak. if its not that then its prob electrical. u could try blocking off the pipe to the booster with a bolt in the pipe to eliminate it, but dont drive far like that, the brakes will be unusually heavy...

 

Hmmm, mine does this too; if I repeatedly tap the brakes I can raise the idle 400 rpm easily and cause the idle to bounce... I've replaced the master cylinder and booster, as well as the hose to the intake manifold and the one-way valve inside and nothing fixes it

 

The extra air released into the intake manifold from the brake booster when the brake pedal is released can cause the idle speed to rise as it goes a bit lean, and vice versa. this is nowt to worry about. i've never noticed it be more than about +/-200rpm but i guess it could be a bit more. i think the problem mentioned here was a bit different. a good way to test if its acting normally is have the engine idle and hold down the brake pedal, if the idle returns to normal pretty soon (as the pressures equalize) then dont worry. also idle the car, leave it for a while(overnight,say) and then, without startin the engine, press the pedal. there should be a few powered pumps left in the booster, if not theres a leak. if none of that shows a fault then just leave it in gear longer and stop worrying.

 

i have the same problem as well, i run the 12.1 inch wilwood dynalites and i have always figured that the idle flucuation when you pump the brakes was normal. its never caused me any problems, actually i never really considered it a problem. i always figured it to be excess vacuum draw at idle and the motor increases idle to keep up with the vacuum draw.

-Peter

 

all of this is NORMAL for honda's

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by antone &raquo;</TD></TR><TR><TD CLASS="quote">all of this is NORMAL for honda's</TD></TR></TABLE>


right on the dot,mine does it too

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by raene &raquo;</TD></TR><TR><TD CLASS="quote">Hmmm, mine does this too; if I repeatedly tap the brakes I can raise the idle 400 rpm easily and cause the idle to bounce... I've replaced the master cylinder and booster, as well as the hose to the intake manifold and the one-way valve inside and nothing fixes it </TD></TR></TABLE>
LOL Nothing fixes it, huh? It could be that there isn't a problem with it to begin with.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by antone &raquo;</TD></TR><TR><TD CLASS="quote">all of this is NORMAL for honda's</TD></TR></TABLE>

Mine does it too, but just the same, check your brake light switch (by the brake pedal) to make sure it works and is adjusted properly. I remember reading someplace that the computer will detect the brakes being pressed and will try to compensate to minimize the bouncing idle. I THINK it may have been it the trouble shooting section in the HELMS, but I'm not positive.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chiovnidca &raquo;</TD></TR><TR><TD CLASS="quote">
LOL Nothing fixes it, huh? It could be that there isn't a problem with it to begin with. </TD></TR></TABLE>

One could only hope

It just doesn't seem right that you can simulate a massive vacuum leak by tapping the brakes repeatedly, though.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by UK CIVIC B16A2 &raquo;</TD></TR><TR><TD CLASS="quote">

Hang on, are you under the impression that the brake booster is something electrical???? hate to rain on your parade but its not. u cud mean the brake lights, but this could never cause the idle to fluctuate...
</TD></TR></TABLE>

Nope. I am aware that the brake booster pushes from the engine vacuum. I worded it stupidly, though. I was talking about faulty vacuum sensors (on the engine) allowing inadequate vacuum for the booster (no codes would be thrown). However, if there was a problem like this, then codes would be thrown, so scratch that.

Does anyone else feel that an 800rpm fluctuation is a bit excessive? My car fluctuates +/- 150 rpms under brake depression, but a span of 1600rpms is pretty large. I don't think that sounds normal.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by raene &raquo;</TD></TR><TR><TD CLASS="quote">

One could only hope

It just doesn't seem right that you can simulate a massive vacuum leak by tapping the brakes repeatedly, though. </TD></TR></TABLE>
Seems right to me, it takes alot of vacuum to operate the power brakes.