I tried to figure some things out in the all motor forum, but I figured I'd ask you guys too....here's the run-down

I installed my VI yesterday. 5th gen upper on the 180 degree'd 4th gen lower, but was only able to use 4 bolts to hold it down - one on each end and two in the middle front (the same bolts that hold down the stock intake). I used the 5th gen IACV and TB. I had to remove the little branch thing that has 4 or 5 vacuum/fuel/coolant lines running in it below the TB and just spliced them together. Now I couldn't swear that the TPS is correctly adjusted and that the IACV is working correctly, but when I started the car it just idles up and down between 1500 and 2500 RPM, and does it cold or warm. Anybody have the same problem or clues as to whats causing mine?

 

Anybody got an idea?

 

try this link...

http://forums.maxima.org/showthread.php?t=443176

I am sure you did your research before you went hook everything up....

 

What did you do about your EGR?

 

Well I bypassed the guide tube but left everything else hooked up. I've spent several days trying to figure out what would cause the idle surge, and came up with nothing. I have to have the car to drive, so I put the stock intake back on today and other than a slightly high idle, everything works just fine

 

It sounds like an engine management issue.
1. Are you sure there were no air leaks?
2. If you know there were no air leaks and are sure everything was properly installed, then I have to consider that this random 'hunting' up and down, at an untypical baseline, indicates that some basic - and expected - item of information is missing. The ECU can't manage the power plant because it lacks sufficient control to do so. (Open loop on one or more systems). In physical terms, that translates to: sensor(s) is/are unplugged, broken, incorrectly installed, or wrongly specified (e.g. you put a 5th gen IACV on it, but do you know that a 5th gen IACV is correctly calibrated for a 4th gen ECU?)
You'll need to review each separate path of engine management to do with the intake. Eliminate from your review items common to both. Home in on any changed items. Before trying your swap again, put a DMM on every sensor involved, and measure its typical value. After the swap, verify that compatible figures exist.

 

That does make sense. I could only come up with one way there could have been an air leak that I couldn't find as I thought it was odd that it wouldn't have been possible to redrill the lower like some other people did when using the 4th gen lower, so I'm without a clue. I'm just going to try and source the other 5th gen parts to do a more complete swap

 

And the idle values were almost completely constant 1500-2500 up and down as if someone was hitting the gas

 

there's your problem, buddy.

Are you using a 4th gen IACV? Cause the 5th gen won't work with a 4th gen ECU. Also, correctly adjust the TPS.

 

I did go back and reset the TPS after I got the nominal values out of a Haynes manual. However, I had been told that the 5th gen IACV would work wth slight modification to the 4th gen IACV plug.
http://forums.maxima.org/showthread.php?t=447838 post#26