first off vehicle is supercharged and has a complete 00VI engine swapped with IACV adapter for 99 IACV, have tried 2 different IACV's the one that came with the car and one i was told was good, both have same effect. when on cold start have to hold the throttle for about 3 seconds before i can let it idle on its own, it will not raise idle when cold stays at about 550-700 rpm. on decel when coming to a stop and the clutch is let out it does not up idle, will sometimes die, sometimes it wont, have cleaned connectors and IACV itself, checked to make sure adapter was tapped correctly and inline with IACV solenoid, which it is. only thing i can see that is obscure is the brass fitting to the intake mani is smaller than the one coming off the adapter plate. no vacuum leaks and no hoses plugged or kinked.

browsed through search about 5 pages and found no description that i seen may help.

 

Just up the Idle to 800-900rpm's with the idle screw. Don't give yourself headaches with a system that wasn't meant to be run on a 4th gen ECU. My maxima idles fine with an 00vi. If you really want to idle perfectly get yourself the IACV adapter plate and attach your 4th gen IACV on it.

 

the idle screw does nothing, i can take it completely out and it doesnt change. but i see you didnt completely read, i have the adapter plate already.

 

Sorry, must have missed that. In any case I'm talking about the screw that opens the throttle body. You screw it in more to increase the idle by not allowing the throttle body flap to fully close.

 

yea i thought you may have missed it. i would like that to be a last option but i guess ill try it out.

i also forgot to mention i have to have the emanage tuned to give the car more fuel when at idle for it to run.

 

Whats your A/F at idle? Also I'm not sure but the hose for the IACV plate should be bigger to provide it with sufficient air, I believe I read that somewhere.

 

the a/f at idle is around 14.7 once it actually idles smooth, but when its idling low and rough its around 16-17 the hose is slightly bigger but like i was sayin the barb on the line hooked into the intake is smaller than the one on the adapter, so i was thinking its possible, that like you said the air going into the intake is not sufficent enough.

 

I don't know how forced induction VQ30 are but in my other Vehicle's turbo V6, I had to richen the idle up to 14.0-14.2 range to get a good low rpm idle. It won't smell rich and it should still pass the sniffer test. I know of few people with more agressive cams with turbos who have their idle adjust around 13.0:1 afr

 

it smells terribly rich, but i dont have a cat on it. plus its obd II so no sniffer anyways.

 

When I start mine up its at 13.5 or so then jumps to 14.7-15 when it warms up. Only messed around with the tune on the map. I guess fire up the car when its cold ( I believe less air goes in) and tune it for 13.5 A/F as the car warms up the IACV allows more air to come in to lean out the mixture. I think and I'm trying to recall how I did it.

 

I had this same problem. I posted about this in the all motor section. I finally figured it out, you need more air going to the IACV. I installed a bigger fitting in the manifold to allow the iacv to get more air. Once I did that it idled like stock. You should not have to adjust the factory set idle screw. If you search my threads in the all motor section you should find the thread that I started. Hope this helps.

 

thanks man, i was thinkin that but wasnt sure, would you have to tap the throttle on cold start up for a sec or two after you fixed it? car looks like pure sex BTW, you runnin on Konig Villians?

 

I did the same thing and then ran a larger hose from the back of the intake manifold and then ran it to the nipple on the adapter plate. I am using a 5th gen TB and 4th gen IACV w/ the blockoff plate.

I still have a cold start issue though, but it isn't enough to bother me. One tap of the gas and it starts without any problems. It is still way better than running the 5th gen IACV and having the car stall on me while driving.

 

cool my main concern is the idling issue, not cold start. this 5th gen issue, is it common just for the 4th gen guys to have it, or is it a common 5th gen problem, if it is, i know the reasoning for it, just from working on them so much.

 

Once I used a larger hose along with a larger nipple I did not have to tap the gas at all. The idle was smooth and started like stock. One of the guys that posted earlier (dgoodhue, I don't remember exactly how he spelled his name) but he has one of my old manifolds with the bigger nipple. I'll see if I can find a picture of where I put the nipple.

Thanks for the comments about my car. I am running Enkei RP02's.

 

Did you add a larger nipple? I think I posted the size of stuff that I used in my thread. If you just added a larger hose that is not going to do it.

 

yeah I had the same problem with my 3.5 swap the nipple was not providing enough air ran a seperate fitting but larger than the adapter plate and it started and idled like stock

I am going to drop a dek in this time with no iacv and just deal with the cold start problems since it's no longer my daily

 

here is where I put the larger nipple on my 95 with an 00VI. I know you cannot see the size in the picture, but like I said I am pretty sure I posted the size in my thread. I drilled out the existing fitting and then JB welded in a brass fitting.

 

FWIW - I'm using 1/2 inch O/D nipples on the IACV blockoff and UIM plenum (drilled and glued with Fusor 142) connected by as short a 1/2 inch I/D hose as possible (approx 4-5 inches). IACV is in stock position +/- a 1/4 turn with the TB plate (pathfinder w/coolant bypass IACV blockoff) opened to emulate an A32 TB closed position (reads approx 0.7-0.8 on TPS at closed position/4.0ish volts at WOT) warm idle is at 625ish, starts in -40C temps.

With this setup, the only mechanical variation inputted to the ECU that differs from a full A32 setup is that the 'closed' throttle plate TPS reading won't come down as the car warms up, where as with an A32 TB it would (as coolant warms up it closes the plate by softening a little wax plunger that keeps the plate slightly more open while the car is cold - essentially 'feathering' the pedal for you).

 

I added a larger nipple to the IM but not to the blockoff plate....did you get a 1/2" fitting for the blockoff plate too?

IIRC they use 3/8" nipples on the UIM and the blockoff plate, but I could be wrong.

 

I just added the larger nipple to the IM not the adapter plate. How long is the hose that you are running from the IM to the adapter plate? Mine is probably 6" long at the longest.

 

Mine is probably about 18", has a few 90* bends too, I've been meaning to clean it up...as my IACV sits on the opposite side of the midpipe (from the TB).

Maybe a shorter hose will do the trick? I got the 5/8" hose too to fit over the larger nipple and then put a hose clamp over the smaller 3/8" fitting on the adapter plate.