Ok did an AEBS intake manifold swap about a month ago and ever since then I have had a messed up idle. It acts just like an IACV problem with the idle bouncing between 1,000 and 1,600 constantly. Usually takes about 1-2 minutes for the idle to start bouncing from a cold start. If I unplug the IACV the idle drops and stops bouncing, im not throwing any codes, I have switched to a different IACV and if I take off the intake and cover the hole inside the TB nothing happens. Ive checked all my vacuum hoses (i hardly have any with no purge, charcoal canister) no leaks there. The manifold sorta sounds like its sucking air when my idle is bouncing so is that my leak? I used a new IM gasket. Also I have bled the coolant system and all that. The AEBS uses NO fitv valve so I know thats not it. I just ran a hose from the small nipple to the TB where the FITV was. Should I try loosening all the bolts and re-torque it? Ive tried spraying carb cleaner on the IM, head mating surface but its hard to tell if the idle changes since its already bouncing up and down and my loud exhaust. Anybody help me out here?

 

I beleive you have to put the charcoal canister connection and valve back in to get the correct idle with the aebs. I have an AEBS for my B16, and have red almost every post on here about it and I read the same scenario where he left the valve out that goes to the canister and had the same problem as you.

 

i dont think the charcoal canister has anything to do with the idle being messed up. It has to do with fuel vapors, but i will look into that. If you cover the TB hole up with your finger isnt the car supposed to idle down and maybe even quit if the vacuum is NOT leaking?

 

no love tonight?

 

It seems like it wouldn't but I know I read that it does, I made sure to swap that line and valve over to my aebs

 

so your saying to only swap the valve on top of the charcoal canister and nothing else? What about covering the hole in the TB like i mentioned. That should change the idle somewhat. Also what about the sucking sound it makes around the manifold? I cant feel a leak but it sounds like it and whenever I feel around to for an air leak the dizzy usually shocks the **** out of me. Im gettin frustrated. i dont think i even have my charcoal canister anymore

 

Is it a B16A? I accidentally got the wrong IACV once for a b16a3, and then got the b16a and it seemed to work out. I know there is a difference between the IACV's, and it wont work if you have the b16a2 or b16a3. Just a suggestion.

 

the other one is slightly different but I dont think the problem is in the IACV because once you unplug it the idle drops (so that means it works especially when you plug back in and it clicks) but still slightly surges? Will a vacuum leak cause the slight surging of idle after unplugging the IACV?

 

lots of help

 

You need the valve that inserts into the manifold and the piece that connects to the canister, then connect it all to a nipple on the back of the mani. I 've read that the AEBS makes a whistling noise regardless, so I wouldn't worry about that. I wouldn't really worry about the IACV sense most people leave it off and have no problems.

I have an extra charcoal canister if you need one

 

I get frustrated here too, on some things you just wont get much help (like on my aebs post), but keep bumping it up

 

well when driving it does make a whistling noise between 3-4k but no other times. Im gonna try to retorque the IM and see if that helps. My revs are slow as hell and it just dosent seem like it has a lot of power now.

 

If it was leaking from between the head and manifold your idle would go from about 800-2000+ constantly searching for an idle. I put the Edelbrock on my old boosted SOHC and the manifold didn't sit flat against the head and it idled like ****. I ended up having to silicone a $300 manifold to the head to keep it from leaking (but it worked, never leaked again even under WOT and 7psi)

 

u could run water across the intake were it meets the head and car will bog and die if u got leak!...

 

the stuff all over the manifold and vacuum attachements and the head area. If you have a leak it will bog the motor.

 

this is a long shot. but did you disconnect any coolant lines? I had an air bubble in my system once and it idled like that. It happened when I changed the TB. When I disconected the coolant lines that run up to the TB I somehow got air in the system.

 

nah not really, i just ran a straight line in place of the FITV, and have bled the coolant system as good as I know how. any other suggestions?

 

re-tightened the IM and found out that the air sound was air blowing out of one of my broken valve cover bolts. If i cover the entire TB the motor will not bog or die. So there has to be a vacuum leak somewhere. Getting ready to try carb cleaner spray again. If i unplug IACV idle dropsdown, there appears to be few drops of coolant from the back of the IACV dripping ocassionally,

 

check your idle adjust screw. screw it in all the way. some times the sealant around it dryrots.

 

I just put mine on yesterday and it idles just like stock. I used a ANR manfiold gasekt. I have no charcoal canister or either of the little solenoids that was next to it. the only vacum lines that goes to the back of my mani is the brake booster, pcv and the fuel pressure regulator I have the other one pluged up. The idle was bounceing from 1500-3000 which turned out to be the manifold needed to be retourqued. then it still fluctuated from 800-1500 which turned out to be the pcv and the brake booster lines on the back of the manifold was loose so I put some couplings on them and now everything is fine. Also the idle will still adjust from 250-1200 so I don't know why everyone has a problem with it idleing to high.
later
Matt

 

yeah that sounds about like the setup I have except I figured out that if I unplug the line that comes from the breather box that I have plugged onto the back of the AEBs then the idle is fine. What if there is no PVC in that line? If i put a pvc in the line will that help it or can I just leave it unplugged? Also if I do get a PVC does it need to be plugged right ontop of the breather? Where is the small hose running to on top of thebreather i can see it but can feel or see where it goes