I bought a 95 integra shell months ago it has aftermarket brake lines..abs delete .. Every since the first day I put the motor in the car revs up and down 1500 to 2500 ..in the morning idles at 3k.. I've changed about 3 Iacs now I know for a fact this one works and today I swapped out the tb wit one that has a block off plate for the fiv.. When I started up the car it's was idling at 1300.. Then wen it warmed up idled up and down 1300 to like 100 sometimes it stalls.. Then I disconnected the brake vacuum hose and it's was idling almost perfect at 800 and it was a little jumpy maybe becuz I have stage 3 crowers? Would only jump to about 900 .. So wat would i have to replace ?

 

i would try to change out the tps when a honda idles up and down like that its usually that

 

i doubt its the TPS. main things ive found to cause idleing up and down are
1. FIT valve on bottom of throttle body (you've already tried this)
2. IACV (done this too)
3. or a vacuum leak

so it idled fine with the vacuum line to the FPR plugged? then that sounds like the FPR isnt holding vacuum. you can test it with a simple vacuum pump. it should hold at least 20 in of vacuum. if not, they are cheap just try another one.

 

Huh? Did u read it I said brake booster not fpr .. Could this be my problem never heard of this happening

 

3 questions:
1.how do the brakes feel normally?
2.where exactly did you disconnect the booster vac line?
3.did you cap it off at the engine side afterward?

 

When I'm stopped or driving my brake pedal in acting like the vacuum leak it's goes in and out along with the idle.. I disconnected the hose from the intake manifold to the booster then covered the hole wit my finger on the intake .. Seemed to run fine didn't wna stall but I would love to take it for a ride and see if I would idle up and down or stall after driving. So is this the brake system that is leaking? I've never done a booster before and it doesn't look like fun

 

you can isolate the problem by hooking up a vacuum gauge to the engine. start the car and take note of the reading on the gauge. this is your base reading. next, disconnect the line leading to the booster and cap the nipple on the manifold. if vacuum increases above base you have a leak in either the line or the booster itself. isolate it further by reconnecting the line and plugging the end that goes into the booster. if once again vacuum is greater than base, the booster or grommet is leaking

 

Would this vacum leak cause it to stall out and idle around 100-200

 

sure could.
TBH, it sounds like you've isolated the problem to either the line, or booster itself. try reconnecting the line, running it and pinching off the line between the booster and check valve. if it runs fine with it pinched there, leak will either be in the booster or at the grommet. if not, problem is in the line, between there and the intake manifold
did you by chance change the master cylinder before this started happening? because there is a gasket between the master and booster that usually stays with the master when it's removed. if attention isn't paid, the new master will be installed without that gasket. if it's missing, it will cause a bad vacuum leak
usually if the booster diaphragm is leaking, you will notice a hissing sound

 

Replaced the brake boost and still the same thing car keeps idling up and down I just bought carb cleaner and spray everywere I could on the manifold and tb nuttin didn't want to die just kept idling up and down ..and the car keeps stalling constantly .. If I drive then come to a stop the car will idle up and down and from the on the idle gets lower and lower till it eventually stalls??????????

 

Are you tuned for the cams?

 

It's not cuz of a tune that it would make it idle up and down .. But yea I got s300 my a/f is on point .. I forgot to mention when my car is about to stall out it is rich as he'll in the low 10s

 

I would check the actual rubber hoses/lines themselves and make sure there isn't any cracks or holes.

 

Checked all the hoses yesterday nothing sounds like a have a huge vacuum leak just at idle .. Could this caused by timing off a tooth ?

 

try spraying the carb cleaner around the lines to the booster and check valve.
the fact that you removed the line from the intake mani, plugged the inlet on the mani, and the loping stopped, is a pretty good indicator that the problem lay in either the line or the booster

 

add some timing below 1000rpm 3-4 degrees it will keep it from stalling just in first few cells.also increase iacv duty cycle.

 

check pcv

 

well, you may as well check your base engine vacuum then. if it's low (which could be caused by a tired motor) you will have this problem. just that how you described it (which could have been lost in translation), the booster or line to the booster was the problem

 

I had the same problem on my f150... it was a rotten hose that led to the engin your leak may be covered by foam insulation normal it will just idle rough and die out if you keep you foot on the gas it won't if you start you car up and rev the engin and it dosnt die out until you quit reving your its the pcv valve and hose change them and the groment also"if they are rotten" if you put it on a machine it should say your running lean don't get a mass air flow sensor like they'll tell you to.... if you still can not find the problem take it to a mech you know and trust.

 

Easy way to know if its a leaking hose rev your car up if it only dies on idle its probaly a vacum leak... I had the same problem on my f150 the rotten part was covered by foam.... if you ses light is on take it to auto zone and have them test it it will probaly say your running lean which is to much air... they will suggest a mass air flow sensor don't buy it just check you hoses they might be loses broken cracked or rotten the chemcails eventual eat away the hoses this is normal I just don't want you having to spend the kinda money I didtill I found out it was a 60 dollar hose and pcv valve and if it happens to be the same prob I had change the groment to... if that don't help lmk cuz the next thing I can think of is expsive and a last resort imo

 

Crap didn't think it posted the 1st time sorry

 

I wonder if this could be a problem with my 92 civic hatch? when i pump the brakes at any time the pedal goes down all the way and the car seems to feel like its stalling but the brakes stay holding