Rep Power: 224

So over sized TBs must not be all that popular because I don't see many threads concerning them. The issue I have is that I'm using this and as you can plainly see, there is no hole for the FITV, leading me to beleive that the FITV has no vacuum through the TB.

Now on to my problem.

My car idles like ****. It hunts for an idle, surges, hesitates etc. I've tried setting my idle like the OEM service manual says too, (unplug IACV at OT, set to 800 blah blah blah) and still i have a meandering idle. So my question is, what the **** do I do to make my needle quit galavanting around my tach? I have no vacuum leaks, I spent all day form 10 am yesterday until 3 am (right now) checking lines for leaks broken seals grounded wires etc.

What I've tried

Capping one of the IACV ports= car runs like absolute ****
Running one vacuum and one coolant= coolant in cylinders, lots of smoke, car runs like an even bigger pile of ****
Bypassing the FITV and running coolant line directly to IACV= car runs ok for a while, then also, runs like total **** and is undrivable after idling for 30+ seconds
Run a coolant line to TB and TB to IACV= meandering idle but car is more drivable.

Does anyone out there have a large TB and have this problem? Does anyone have an idea? My TB is identical to the one pictured above.

 
Rep Power: 224

before i go to bed bump

 
Rep Power: 813

i tried the bored out stock tb from maxbore.com and kept getting TPS voltage problems and my auto trans would barely function (stays in gear, shifts at the wrong rpm, etc). didnt keep that for very long. our tbs are very sensitive to any change. even when removing the coolant lines on the stock tb i had serious idle surging.

 
Rep Power: 224

thats basically whats going on with mine. The issue i had at first was TPS voltage, i adjusted it to spec but it would never sit right. I put the stock throttle wheel on and it fixed that immediately, turns out since the enlarged throttle wheel is so much bigger than the stock one, it throws the voltage off (i guess) I mean its a spoon TB and Spoon doesn't make anything that can't be street driven so there has to be a way around not having a FITV. What about when people do the FITV bypass, do they get IACV problems? I have a code 14 and the IACV is conencted right (sans the FITV) im sure so do you think just the IAC is fooked?

 
Rep Power: 0

ill tell u what u need. Kpro, idle is adjustable

 
Rep Power: 813

my car didnt have a fitv and still had issues. it was basically a bone stock tb with all sensors, except the bore was increased a few mm and a larger plate added. it idled just fine, but everytime i tried to drive it somewhat aggressively (over 4k rpm) it just turned the cel on and it was all messed from there. i was lucky to limp it home. in your case, either you do not have a good seal between the plate and tb, or your sensors arent able to work with the larger port size. does your tb have the air port on the side to bypass air around the main throttle plate? if not, theres your problem and no amount of tuning or fixing will help idle. with the plate in closed position, thats the only passage that air has to move thru to the engine, and its controled by the iac as the car warms up.

 
Rep Power: 256

sounds like a TPS issue. in the older hondas, a bad TPS signal/sensor will make it rev all day. i dont know about these cars.

 
Rep Power: 813

tps is fine, it just wont work properly with a modded tb, even after calibration.

 
Rep Power: 224

TPS is in spec and its at perfect voltage at idle and at WOT but the code 14 pops up and if i stand still for 5 seconds i get a wicked loping idle and i can't drive the car. No TPS code. Like i've said im not sure if the IAC really is bad or if its because im using a 70mm tb