90HatchSTD

Alright, i swapped out by b16 for a b18c 2 weeks ago. When i first put it in, it idled kinda high, but after driving it for a week it literally idles at 3K. I crank it up, it idles at 3k and climbs to 4K as it warms up!?!?!

I did the fitv thing by screwing the plunger back into it because it was loose and that didnt fix it. I took off my iac valve and cleaned it really good and that did nothing too. But, on the throttlebody there are 2 small holes in the throttlebody one of them is sucking in some mad air. When i plug it with my finger it idles like normal. I figured that had something to do with the fitv so i bypassed it by running the line from the thermostat housing strait to the one in the back of the head and not using the fitv ports and that still did nothing. Someone please help me with some ideas.

I have checked for vacuum leaks by spraying carb cleaner and i have no leaks, the throttle cable isnt to tight, and the throttle plate is closing all the way. What else are those ports going to in the throttle body? My car is a 90 hatch, with a b18c, and i am using an obdo pr3 ecu.
thanks in advance

90HatchSTD

BUMP!

jackstands

Which hole fixes the idle? The bottom one is the FITV, the top one is the IACV. Whichever one it is, it's leaking air. Redirecting the lines does not fix that problem. In addition to redirecting lines, you also have to make a metal gasket that will plug air holes in the fitv.

90HatchSTD

yeah its the bottom one that is sucking in the most air. When i put my finger over the bottom one it idles fine. So that one is for the fitv? is there any way to fixing that without replacing it? I already took it off and screwed the little plunger back in. How much is a new fitv from honda?

Atheist

What about the nipple for PCV on the top middle of your intake mani? Is that hooked up?

Have you adjusted the throttle cable?

90HatchSTD

all the vacuum is hooked up, including the pcv system and the throttle cable is fine. I know for a fact it has something to do with the fitv. I just need to either figure out if i want to replace it or bypass it. I've already done the fitv trick by screwing the plunger back into it. Any other suggestions? Thanks Again

JimBlake

It may be that your FITV is bad anyway, not simply loose. You may still need to replace it. If covering the bottom hole changes the idle even when it's completely warmed up, your FITV is bad. I think when the FITV guts come loose, the idle is unsteady, not just high.

It could also be your PCV valve. Not just disconnected hoses, but if the valve is bad it could do that.

If you need to set your base idle:
- Warm up the engine completely, turn off ALL accessory loads.
- Unplug the IACV. It might want to stall, so use the throttle & carefully let it close.
- Idle adjust screw is above the bore of the throttle body. Adjust to 480 rpm.
- When you plug the IACV back in, the idle should go back up where it belongs (800?).