Hi
Fist let me just say what a great forum.Congrats to all who made this possible,Mods,admins and members.
It's a great honor to be part of it.
Well I have been visiting this forum a lot lately.
I don't usually work on oem cars tho.
I have a friend who owns a Maxima 03 and he has been having some problems.

I decided to get involve since he was another victim of bad mechanics. Trust me I went and looked for the info here and found one that said to do the ecu reset etc while cold.To do the last idle learning while the engine has reached normal temps.

Here is his problem.
Idle throttle a bit to high.
I scanned it and it had some old storage codes.
Random missfire
idling high

The rest checked out ok.
Now I fixed the random miss fire by swaping coil number 5 and the valve cover which was leaking oil to the plug it self and coil boot.Changed the sparks plugs
and changed the throttle body.
Since he cleaned the old one with carb cleaner.
I cleared the codes and reset the ecu.
did the close throttle learning.
Started the car and warmed it up on the dyno which I did 23miles.
did the idle learning and cleared the idle high code.
Some how there is no relay from tps to ecu.....
So the car is very similar to 350z and g35s....
anyway.


I cleaned his maf and all ve exterior related parts.
also built him a better engine mount to improve shifting and not have to use those engine torque dampers.
before


and after


Now when I did the tb idle learning it accepts it and idles at 7k or so
When I turn off the car and wait for more then 3 sec it goes back to high idle.

Like I said I don't do oem cars only race cars. So I don't have Consult 2.
I work with hks and other efi units.
Anyone have had this happen?
By the way I followed the fsm on ecu idle learning and reset.
But as soon as I turn the ignition off for more then 3 sec it goes back to this high idlle problem.

 

If he cleaned the TB by hand with the key off and moved the throttle plate by hand there is a 90% chance he will need a new TB these things are too sensitive for no reason

 

I replaced the old tb with a brand new one.
Which cost him 120 bucks with my discount in nissan parts.

 

What's the mount made out of?


Personally, I never had any good luck with the manual Idle re-learn. I'd just call up Nissan and find out the cost to plug in and do it.
Someone might have better news on that one

Before you do that though make sure you don't have vacuum leaks/intake leaks, which is what I'd suspect here.

And come on, you're idling at 7k????!!!!!?????




lol

 

the idle is steady at 7.9 or 7.8 and when i turned on the ac or lights goes to 8.6 or so.This is besed on my actron obd2 info.Can't remember correctly the exact rpm but I don't remember seeing it at 8 with the ac or lights off.
I checked for leaks and has a small one on the upper plenum.
should drop idle and not higher it as far as I know.Being that the car is similar to the Z33 and g35s which I have experience of.
But still doesn't explain why it resets the idle when the engine is off for more then 3 sec.
But thanks for the suggestion tho.I told him to contact our friend at our local nissan dealer.


.

 

I"m not 100%, but here's my logic:

A leak past the Throttle body and MAFS would induce ADDED air.

This is also a Vacuum leak at idle.

Fix it and see what happens. Any leaks in the intake system post MAFS, and especially Post TB, will throw your readings for a loop. With an Electronic TB especially, you're going to have idle issues until you repair the leaks.

The car only knows what it's getting for air at the MAFS. IF it's getting extra air after that, then that's going to screw stuff up

 

I get your point
Thanks for helping out bro