Here's the problem on my stock d16a6. Idle's fine on cold start. Only problem is it seems like when the engine's up to temp, the idle speed will be at 1300 revs at neutral and no accessories on. Sometimes it may come back down and hover at 1000 revs. Over the winter it has idled great at the rev mark below 1000k, I'm assuming the 700-800 mark. The manual seems to suggest it may be the EACV.

My brake pedal, after coasting down to a stop, seems to sink down, in that after I come to a full stop, the car will roll with my foot still on the brake at the same spot, if that makes sense. Basically, after I apply the brake, the brakes will let off, requiring me to push on the brake further to hold the stop. But the brakes work great and not soft at all. A mc issue?

I'm also wondering if the brake thing may possibly relate to the idle issue.

What do you guys think?

 

figured it out...looks like when it gets nice and hot under the hood, the throttle return spring gets weak and doesn't shut the throttle all the way. Pulling the throttle back brings the idle back to spec.

 

pull your pssenger side carpet back and see if your ecu is getting a code.allways do this first to rule out a sensor problem.if there is no code then ajust your idle,with the screw on the tb.clean out the tb,also

 

The idle adjustment is not as simple as you make it out to be. The idle air control valve needs to be unplugged, the engine at operating temp, and everything else should be confirmed as working properly first. The ECU controls the idle. The idle screw only sets the BASE idle, typically set at 200-250 rpm below normal idle.

 

i know that, did not have time to get all technical.i agree not as simple.

 

if the ECU is registering a code, wouldn't the check engine light on the dash light up? nonetheless, it's not a sensor issue, it's definitely the return spring being weak when hot. problem is i don't think honda sells just the spring, and i'm not buying a whole tb either.

 

Did you noticed there is a vacuum diaghragm at the throtle stop? Make sure it isn't holding the throttle open at idle. Otherwise, I would guess your fast idle valve (FIV) may not be closing up all the way once the engine is at operating temp, or you have a vacuum leak somewhere, like to that diagragm. The FIV is on the backside of the intake manifold next to the brake booster. (Two phillips head screws on top) Clamp off the rubber hose going to it next time your idle is high. If it drops, the FIV is leaking.

 

i live in fl, and have not heard of that befor.i have a 89 si tb. oh ,the fast idle valve dont do ****.


[Modified by 4gvtec, 8:55 PM 4/19/2002]

 

Haven't heard of what before? And what do you mean by "the fast idle valve dont do ****." ?

 

the tb spring.it dont do ****.theres no code for it.this is how you can run the z6 intake.theres not one on that.im running it.me and jdm hatch argued about this and i went out side with the car running and cut the wires.dont do any thing and dont throw a code.he was right!

 

I will enlighten all of you. The problem is clearly your brake booster. You know how your pedal goes to the floor. THats because the diaphram in the booster is bad. Causing a vacume loss which is the reason for the iratic idle. i bet it goes all crazy when you pump or even use the brake huh. Go replace it and you'll be fine I suggest getting a new master cylinder as well thats probaly what caused the brake booster to fail. A leak in the master cylinder. $90 bucks for Both a H-auto In garden grove

 

that was my second answer.you just beat me to it.

 

The brake booster very well may be a contributing factor, but when he posted he figured it out by "Pulling the throttle back brings the idle back to spec.", it leads me to believe he's got other problems as well. With the engine at warm idle, the arm of the diaghragm should not be making contact with the throttle lever. If that's OK, he's got a vacuum leak, like from the brake booster, or extra air entering the intake, like from a leaking FIV.

 

Well, I think there is definitely a brake issue. My pedal, applying a steady force, will gradually sink and bottom out almost to the floor. So by that, I'm thinking it's either the MC, booster or both. There is no visible fluid leak and the reservoir is completely full. Seems to be getting worse with this warm weather.

Now regarding the idle, the brake issue may or may not be related. But the fast idle when engine's hot, I can pull back on the accelerator pedal and it WILL drop back to spec and hold. Blip the throttle again and it will hover around 1000 ~ 1500 revs. I checked the dashpot diaphram and it is definitely NOT holding the throttle open. It's the same if I manually blip the throttle with my hand. So I'm thinking it's not the cable that's binding.

How hard is it to do the booster diaphram and what else in there should I need to replace?

 

CAMAROCRUSHER, where is H-auto, do they have a website? Is that a price for new parts?

 

First of all, Didn't mean to sound so arrogent. Also H-auto does sell the stuff hell'a cheap but ther is no garrente that the stuff works. For about 2 or 3 hundread you can get it with a lifetime warrente at kragen. The honda dealership told me to replace the booster and M/C and it would fix my crazy idle problem and it didn't. I don't know if it was a bad part or not, but at your own risk ok anyhow the phone number is 714-554-7657.

 

I'm going to take a look at the MC as the cause of my brake issue.

 

No, you misunderstood, its proabably also the brake booster. The master cylinder is most likely leaking into the brake booster and put a hole inside of it. Also did you notice the vacume line comeing off of the booster as well. Ifthe booster is not working than its probably trying to steal vacume from other parts of the engine as well. Thats most likely causing the crazy idle.

 

Well i looked thru the Honda manual and tested the brake booster according to their troubleshoot. Seems like the booster works fine. Also from reading, if the brake fluid is leaking back into the booster, there should be fluid loss. The fluid is full in my reservoir, which leads me to believe that the primary and secondary whatevertheircalled inside the MC is worn causing the brake pressure to drop. I'm not saying it's not the booster, but I'll do the MC first and if I find there's fluid leaking back, I'll get the booster as well.