I just got my forged bottom end APS TT G35 back and I was having major stalling issues at idle. We initially attirbuted this to the JWT cams and I came up with a list of three things to fix the problem

1. Have Infiniti raise my idle via Consult

2. Install a bypass hose from my plenum vacuum line ot my crank case line

3. Tweak the Unichip to allow bettle idle characteristics

Of the three options I felt #1 was by far the best choice, and that is where I started. I called my dealership and they made a little time for yesterday afternoon (perks of having a 500whp car I guess!)

Their master tech plugged the Consult in and looked for idle error codes and couldn't dind any! He dug a little deeper and found that the car had yet to learn to idle. He then used Consult to FORCE the car to learn to idle, but the car refused to do it. The ECU failed the idle learn process because the engine parameters were too far 'out of whack.'

So, the tech dug a little deeper in to the Consult and found that in one of the diagnostic modes it is possible to force idle parameters in to the ECU. Its been less then 24 hours but the car has yet to stall!

FWIW, I called JWT and they told me that ONLY cars built pre 06/03 could be adjusted via Consult, my build date was 07/03. So, either I got lucky that it was still possible with my car, or their master tech found a work around . The car now idles smoothly at 800RPM with AC on or off.

I found this process to be VERY interesting. We were attemping to fix a problem that really didn't exist by just trying to raise the idle. The tech said that the car most likely never would have learned to idle correctly on its own, without forcing it.

 

I read about this at my350z forum on the Group Buy JWT Cam thread, and called JWT to verify. So yes, you got lucky due to the build date on your G. You cannot adjust idle via consult on '04's and up. #2 Fix may work with '04 and up.

 

Mine is an 04.

 

just curious, but what is a car under NA supposed to idle at? Mine idles at the line right before it reaches 0 and it creates some weird popping sound. I went to the dealer once to check it out and they replaced my throttle body, but it still does it. It isnt until I turn on the AC that the needle then goes half way between the 0 and the 1. Should this be something I should be worried about?

 

I would say as long as it doesn't stall or stutter you will be ok. If you contiue to have problems I would recomend installing a TT and the JWT cams and following the above advice!

 

haha... dont I wish

 

Nice find Kevin.
Does this mean you'll need to pay a visit to the dealer every time the battery is disconnected (or whenever your ECU resets)???

 

Yeah I was told by rob at z car garage that you cant raise it on a 04. I rode in the car thats in this months Sportcompact car and it died twice on us.

 

I have a 2004.5 and I raised my idle to 950....sent my ECU to TS.

 

Kevin
Is this a vacuum drop issue? If it is, its most possible it is the cam shafts. I just wonder is there is any input on the "MAF"sensitivity. That can be changed. Possibility, a vacuun can" could help.

 

Time will tell.... I'm hoping this was a permanent setting, but who knows.

 

One more question?
Where you camshafts degreed in to the crankshaft? Big cams can kill vacuum if set in a retard state. In most cases a plus advance helps.

 

I have no idea. I would like to think they were, the guy who built the motor builds more race motors then street motors, so he is performance oriented and has been building motors for 30 years.

 

In most cases a vacuum drop is a big problem for all engines.
Just a simple way to see what is going on is, Hook up a vacuum gage to a vacuum port and see what happens. If history repeats itself. You will find your camshaft timing maybe killing your idle. I would hope this old rule still applies. You need more than 6 lbs of vacuum.
at Idle.

 

I have the Nismo cams and the idle is ruff [ not real bad ] . Had the dealer try to do the learning procedure...no go..wouldnt do it . Kevin....would it be possible to ask your dealer for a print out of what he did to get the learning procedure to work ? My dealers tech doesnt know chit about our ECU and was just barely able to raise my idle to 800rpm .