so I just purchased a 07’ 350 enthusiast model. Previous owner had the battery go dead and changed it, now after starting the idle surges between 1-2500k. I knew that it would need a relearn so I bought the car. Tried an IAVL procedure at least 100 times with a stopwatch, I’ve reset the ECU, throttle vale relearn, swapped the throttle bodies etc. still the same thing every time, revs to 3k when cold then starts dropping to 2k and then up down up down blah blah blah! I had planned on a reflash but the Shop that does it thinks it won’t change it?? Any tricks, I know I’m not the only one who has had a Z that won’t telearn? Also, no codes set, all data appears to be in check except the throttle actuator voltage going up and down. Drives perfect other than idle, disconnect either throttle body while running and it idles perfect but after plugging back in no throttle response until that codes is cleared then instantly starts surging again. If I put it in gear and slip the clutch to lower idle then the voltage stabilizes? Please help before I dump the car I’ve wanted for years!

update, I had the ECU reflashed even though it had the most current update, I checked for vacuum leaks and smoked the manifold. I have tried at least 75 times now and still no change! WTH!!

As I said in my original post I have changed the throttle bodies. I have monitored all pids and All are in check, plugs have 15k on them, no need to change coils as they are working. This car runs flawless short of the idle surging. Seems like people are just throwing parts at these and the problem fixes itself. I’ve read so many posts about the same issue and everyone is doing the same thing but no explanation of what realty fixed it.

I replaced them with a set off a running car with 30 k, my throttle bodies worked on the other car

Yes I did check the wiring and all connections on both throttle bodies. Have not checked the ipdm since the car runs perfect other than the surge, idles perfect at 700ish when either or both TB’s are unplugged. As I mentioned before, the car had run flawless until it sat for a few months and the battery went dead, previous owner simply bought a new battery and installed then this started.

Perfect! I will look this eve. This is the kind of info I’m looking for, I’ve been a mechanic for 30 years but don’t specialize in Nissan. This problem seems to stump many

So last night I checked the IPDM and all connections are clean, I swapped all the relays and still no change. I did find a very small vacuum leak near the center injector on the right bank. With the throttle bodies unplugged and the engine idling I saw a very small change in rpm with a shot of brake clean. I’m going to change all the orings and plenum gaskets evens though I don’t feel that small of a leak is my issue. I ordered the Bluetooth scan module and will download the Niss2 software to see if I can force a relearn.

I had a hell of a time finding orings, had to get the through the dealer! I appreciate your concern about me not performing the relearn properly, I have been a mechanic by trade for 30 years so I’m no dummy when it comes to following instructions. I have performed the relearn so many times I have it memorized, all parameters were dead on and I used a stop watch. I have also tried multiple other combinations all with the same result.

So I just used the BAFX obdII interface and downloaded the NDSIII app which is amazing. Unfortunately I tried numerous times to perform the IAVL learn but it fails every time, also will not perform the Exhaist valve T/C learn. No codes and still all pids appear in check. So stumped!! Idles at 3k when started cold then after about 1minute it drops to 2k then starts surging between 1400-2000k