My set up on my 95 maxima:
00 egr guide tube
00 valve cover and pcv set up
00 LIM
00 injectors
fourth gen TB
frouth gen IACV with adaptor plate

My car runs great when it is warm and no acessories are on but on start up, warm or cold the car does not want to start. If I give it some gas on start up and hold it for a few seconds it will catch. Also when I turn on my AC and lights it causes the idle to drop. The AC makes it so bad that the car has cut off a few times on me when I have clutched it coming to a stop or taking a while to shift gears. Another problem is that when I clutch the car the rpm's will drop quickly to ~ 300 and then slowly rise back to ~600. What causes the idle to drop like that when the car is clutched?

I am really thinking most of my problems are due to my IACV set up. The hose that I am running from the adaptor to the manifold is only about 6 inches long. So its pretty short. I tried using a slightley smaller hose that fit on the fitting better (on the IACV) and that seemed to make my problem worse. Has any one tried experimenting with hose diameter for the IACV adaptor? It seems like it is not getting enough air to function properly.

Should I turn my idle up with the screw on the TB? Will that help to slove anything or will that just mask my problems?

Thanks for any help, I have been reading other threads on this but it does not seem that any one is having all the same problems I am having.

I am throwing an egr flow code, and I am also throwing an idle control code.

Thanks for any help.

 

What idle control code exactly? Also, with the 4th gen IACV, you need as big of hoses on either end as possible, really. You honestly can't go overkill with them.

 

Less air in the motor on start up, the motor is going to starve and shut off...Take a look at the stock 4th gen IACV setup. Its right ON the manifold and getting air right away cause the TB is closed on start up. Some say they are able to run the IACV externally mounted..I was never able to get my car started with it like that.

The only way I fixed this problem was I had a TB block made that holds the IACV as well.

 

An external IACV is just fine. That's how I run mine, and I've never had any problems. It just takes BIG hose (3/4" or more I believe, I can go look if needed).

 

can you please see what size hose you are running, and what style clamps you are using. I am thinking the worm style clamps will not do much for an oversized hose.

The fitting that I have in the manifold now is a tapered fitting. I have another brass fitting in my tool box that I will try tonight. The other fitting I have is not tapered. I am not sure what size it is but its bigger than the nipple most people are using to run the externally mounted IACV. I'll post back once I do this.

Matty, I am aware of the soluition you found, and I would love to do that if it was not so expensive. I really want to try to make the external mount work well enough that I will not have to spring for that kinda jingle.

 

I'm actually not using any clamps on my IACV hoses whatsoever. They all fit nice and snug on the intake and the different fittings.

I went and looked at my hoses; the one running from the intake to the IACV is 3/4" and the one running from the IACV into the manifold is only 3/8". I could have sworn the second one was larger, but I guess not. The key here is to use fittings that take advantage of the hose size. You also can't forget that 1/2" for the barbed end of a fitting is not the same thing as 1/2" for the threaded ended. One is a pipe measurement and the other for hose, which aren't the same. Get one that is straight through (or with the barbed end bigger), and to make sure it's straight through look at the inside, don't just look at the sizes on the box or whatever it comes in.

 

I am currently running a 3/8th hose reduced into just little bit smaller. I am going to putting a bigger fitting in the manifold and run a 3/8's hose the entire way.

You have no idle problems at all with your set up? Where is your IACV mounted? Mine is sitting right next to my TPS against the fire wall. Did you adjust your base idle after you 00VI install. I am thinking turning my idle up to ~800-900 rmp could help out a lot. opinions?

 

Turn up the base idle like ive done for every 00VI swap ive installed and no startup issues at all. Not even a hiccup.

 

did you just turn it up on the idle set screw on the lower part of the TB? What RPM do you aim for?

 

I have never messed with any settings on my IACV, either throttlebody I used, TPS, etc. All my settings were as they were on the USIM. I don't understand how my swap can work out perfect and everyone else seems to need all these fixes

 

Yes, this was all set with the idle set screw on the TB, with the IACV and TPS connected all I did was set the RPM to around 750-800RPM and all is well.

 

how low was your car idoling before you adjusted it?


I only had time to get a new fitting JB welded in last night. It got to set up over night and though today so it should be good to work on later on. I used a 1/2">>>>1/2" brass coupling. I picked up some 7/16ths hose last night. I wanted something a little bit bigger than 3/8s. I update the thread when I am able to hook things up this evening.

 

1/2" to 1/2"? Is it straight through or tapered? If you mean 1/2" thread and 1/2" barbed end it's not going to be straight through. Also, if you have a 1/2" barbed end you should be using 1/2" hose, as well.

 

It's straight though. Its half inch barbed to half inch barbed. Not tapered at all. I am going to try the 7/16s because I could almost squeeze 3/8's hose on the fitting so I figured just a tiny big bigger would work. Also I had a 3/8's fitting on the manifold before and 3/8's hose was a tad to big for it, I had to clamp it down really well.

 

That's odd Oh well, whatever works for you. Best of luck, I hope it idles alright all said and done, even if it takes a little adjustment.

 

I think the IACV just need more air. Last night I finally got a chance to put hoses on my IACV. I bought pre bent heater hoses from my local advanced auto so that the hoses would not crink when being routed the way I wanted to route them. I can post part number is any one is interested. My IACV is between my TPS and the fire wall and I have a 7/16 pre molded hose going from the IACV to a 1/2" brass coupling on the back of the intake neck. Then I have a pre molded 3/4" hose running from my intake to the top of the IACV. I plugged everything in last night and fired the car up. As soon as I started the car the idle went up to 1300 (before I had done this the car would crank and the idle would be around 600-700). The IACV is working again. I think I need to screw the plastic screw in a little bit more since I have it almost all the way out since I am now getting a warm idle of ~ 900-1000 RPM. This has fixed my problem of clutching the car and the RPMs droping down to 300. I have a short drive to work so I did not get a chance to check the AC and lights, but as of right now I am very happy with my results. It really seems like the bigger hose and fitting solved my problem. Now that I know this I will be setting it up the same way on my supercharged car. By the way I did not touch the idle set screw on the TB at all. I hope this helps other people, and I will keep it updated as I find out more. I will try to find the part numbers of the hoses I used for archiving purposes, and I will take a few pictures of the way I have it set up. Thanks for everyones imput.

 

So it was the hoses after all, huh? Glad to hear it was that simple!

 

That seems to be the case. For my application it just seems that 3/8th hose on a 3/8's fitting was not enough to take in the air that the IACV needs. For anyone else doing it I would recomend a 1/2" fitting with 7/16ths hose.

 

great you found out the issue, my question to you is where is the other end of the IACV being connected to on the manifold?

 

I'll try to take some pictures so you can see but it is in place of where a factory fitting was. Its the one that is just past the bend for the throat of the manifold. It's just after that bend close to the fire wall. I drilled/dremeled that hole out in order to fit a 1/2" fitting. I put the 1/2" fitting in with JB weld. After that it was just a matter of running the hoses.

I saved the stickers from the pre molded hoses I used so I have the Advanced auto p/n for them if any one is interested in using the same hoses I used. Of course if you have a different intake set up than me (PR style) then the Intake hose>>>IACV will obviously take a different hose.

 

does anyone know where i can gat a throttle body adapter plate?

 

StephenMax mad them.

And dont dig up year old threads to ask things like this...

 

Revival!:

Happen to have these pics? Im having the cold start issue on mine and trying to take care of it asap. TIA.

 

these are the only ones I have. The car is gone and this set up is too. I did the same thing on my other 00VI set up that dgoodhue has now so if he has pictures. You can do it how ever you like, you just need a bigger fitting and bigger hose.

 

Got it!! Great pics bro!! Thanks Im on this today!! Wish I can rep you a +1 for this...