hey honda tech. anyways heres my problem and yes!!!! i searched. so i just clean my fitv and my iacv because i had a small idle problem that idle between 700 and 1500 so i clean both. so after that i have less of a idle problem and it stop doing it often. but now when im at a stop light the idle is perfect but if i let go of the brake pedal it will idle from 600 to 1200 it does this for about 8 seconds and then goes back to normal. sometimes when i let go of the brake pedal it idles but if i rev it it will go back to normal. this only happens if i let go of the brake pedal. but other than that the car runs and drives great and no cell codes. help please its driving me alil crazy lol. thanks.

sorry by the way its a stock motor and its a first gen jdm b16a obd0.

UPDATE !!!!!!! . ok so today on my day off decided to once and for all fix the idle problem. so i checked all vacuum hoses again and nothing. then checked my brake booster like some said and seemed fine i also checked the brake booster vacuum line and seems good so i decided to go and head and change my brake booster cuz it was the only thing that really seemed to be the problem....so i went ahead and buy a reman from autozone and it WORKED!!!!! YAY no more idle problem ....so i guess it did have an internal vacuum leak. so thanks to everybody that help. so if anybodys car has the same idle with the brake on or off check your brake booster.

 

did u check for vaccum leaks ???

 

yes i checked vaccum leaks. but wouldnt it keep doing it non stop if i had a vaccum leak? it only doest it when i let go of the brake pedal. but thanks for the reply. anybody else?

 

+1 Check vaccum around the elbow on the back of the intake manifold going to the PBB.

 

You might be developing a small hole in the Brake Booster which might be causing a small vac leak. As when you let off the brake, the pressure is no longer there and the vac runs through the small hole.

To test out the theory, I would plug the brake booster line and try and see if it works, I wouldn't drive it like this, just let it sit and idle.

 

i will check this tomorrow. now this morning at cold start it idle good and warm up good. when i left home after warming the car started to idle from 1200 to 700 non stop even on traffic lights. so when i got home i decided to go to pick and pull and get a iacv because i tought my old one might be bad . it was worth a shot but it keeps doing it even with the brake on. im going crazy lol its annoying. so can it be my tps sensor? and yes i checked the vaccum hoses all over again and no luck everything seems ok.

p.s thanks for the help guys

 

Check the tps sensor.

 

yeah thats what im thinkin. maybe tps sensor. how do i check if its working fine?

 

I bet its your fast idle valve

 

i'm with him^

 

i also ha this same problem check if ur master cylnder is properly seated against the brake booster . mine was kinda rusted like it was dipped in sea water and it was causing a vacum leak when i pushed the brake pedal.

also check if the nuts tht hold the master cylnider are tight

and this only happend when i pushed the brake pedal

 

mine idles bad when i have the brake pedal in too i cant figure it out

 

yeah i will check the brake booster hopefully tomorrow i just havent had time. and mine idles bad only when i let go of the brake. thanks everybody for the help. and if anybody has any other ideas let me know. and i will update if i find the problem.

 

dont mean to thread jack, but how do you check the booster? im having a similar problem trying to figure it out

 

might be your brake booster thats just fixed mine today yay. check for my update on top. thanks every body i fixed my problem. yaaaaaaaaayyyyy!!!!!! problem was brake booster

 

How old is the brake booster?

 

the old brake booster was the oem one. seemed old.