simplsi

Tried civic forum, but feel it would be better at home here....

You know when you have been working on a project for ever, you finally finish and there are those little tiny problems that you just can't figure out wtf they are. Well my project has been done for some time now, but I still can't figure out what the hell the little problem is....
The engine:

b18b1 block
b16a2 head
type-r IM port matched

the car is turboed
inline pro mani
t4 turbo
percision aftercooler
TIAL wg
inline pro BOV
blah blah

The problem:

When the car is started everything is fine, it idles where we set it at 1k until the warm up process is over. Right before it hits mid temp it idles up to 1500, then as soon as mid temp is hit, it idles up to 1800rpms.

The high idle is annoying but not the problem although I think it is directly related, the problem persists when I drive and finally hit boost, the cars idle fluctuates between 1k and 1800k. It also has a problem when I am stopped and begin to let the clutch out and push the gas in where it is idling at 1800rpms I don't push the gas nearly as much but then the rpms do their random idle and it jerks the hell out of the car.


If you unplug the IAC it stops being irratic and idles perfectly (3rd IAC, just on this problem, so it isn't a bad IAC).


Cliffs:
irratic idle

What I have tried to begin to fix:

I have read every thread I could over a 3 month period

new IAC
new TPS

I have tried everything cleaning and replacing wise, minus a new IM. I have checked as many vacume connections as I could possibly find with no luck.

This is begining to be one of those problem that makes me want to not drive my car, and I love the thing.

any ideas of where to look would be greatly appreciated guys


Running Hondata s300

The reason I am not leaning towards vacume leaks is when I unplug the IAC, the car runs fine besides for a check engine light, and if it was a vacume leak wouldn't it leak all the time no matter what sensor is plugged or not.

Unless of course the vacume that connects to the IAC is only activated when the sensor is plugged in. is that even possible.

dbiker207

check the fit (fast idle thermal) valve. the part attached to underside of the tb that has coolant running through it. take the brass colored cap off that has 2 screws in it and thread the white plastic thing back into the body of the fitv.

dbiker207

another way to check it is to take off the charge pipe from the tb, there will be 2 small holes in the firewall side, inside of the tb. cover the holes with your finger while the car is idleing iraticaly, and see if it returns to normal or changes significantly. if its the bottom hole check the fitv and if its the top hole it has somthing to do with your iacv

simplsi

I didnt think the Type-r or B16a2 had a FITV. If so, I need to check that right away, I will look shortly, thanks.

m R g S r

vaccuum leak then....check the injector seals at the base of the injector. . . .

JaredKaragen

Vac leak

leaky IACV seal

leaky FITV seal

white screw inside FITV could be unscrewed

Reset idle:

warm up car completely,
jump service connector,
once warm unplug IACV, and stabilize idle,
Hook up a digital tach (make sure it is calibrated and not worn out like your OEM tach which can be off sometimes)
set idle to 150RPM below "traget idle" in the ECU (for OEM, this is 650)
maintain a steady idle, if erratic, there is a vac. leak,

Turn key off.

Pull ECU backup fuse

Wait 20 sec

plug in IACV,

put fuse back in,
Start motor, don't give it gas. If all is well, it will stabilize at target idle.

Try looking in your distributor for metal fragments built up on the pickups, this could cause a misfire that might cause an odd idle situation.

Hope it helps!

bigbadboy

send me a your file to look over it. sometimes if everything is not set in harmony with each other it will cause the idle to be weird

simplsi

Jared, thank you very much, I will try exactly that tonight when I get off work.

bigbad, as well when I get off work, I will send you my file.

Thanks for the help guys, I'd love for my little monster to be in perfect harmony.