Ok so many of you know that I have recently made a fully built HR. Car has come out amazing motor runs super smooth, but that brings me to my problem

My idle on cold start up if fine. It starts out high of course to warm up and eventually stops at about 1k. Once it's at full operating temp and switch loops it creeps up to 1800 and will surge and drop to about 1100 and instantly back to 1800 continuously. If your driving around town the car runs perfect super smooth until you have to stop then back to the idle bounce. We have performed a vacuum leak test with both a smoke machine and compressed air. We held 10lbs pressure with no issues and couldnt find any issues with the smoke machine either. The tune was checked and is fine. The relearn was done by us multiple times and also by Nissan still not fixed. We replaced the throttle bodies with a set off a running HR motor and still the idle surges.We tryed different MAF sensors also.(voltage checks out fine) We have hours into trying to fix this issue and I know many of you are amazing with these cars and just looking for some help and suggestions.

Thanks Guys!

PS
I have Osirus Tune on the ECU. Nothing has changed from when the car blew up till the new motor went in. and all the fuel trims and all check out flawless.

 

Sounds like you need an ECU flash, or have your idle razed between 800-1000

 

I have Osirus Tune on the ECU. Nothing has changed from when the car blew up till the new motor went in. and all the fuel trims and all check out flawless.

 

Do you you have cams?

 

Stock Cams.

 

Questions I was just talking to someone who said that the thermostat stck open might cause a idle issue. My gauge sits a lil over 1/4th the way up not even half way. Any comments? Im no pro lol

 

That happened to my stock HR with the re-flash and twins and Sam said that I need to take it to the dealer to reset the MAF sensors with the NISSAN CONSULT III. Haven't tried that yet.

 

i had the same issue with my old car (07 HR z). It was a flywheel speed sensor they forgot to plug back in after a clutch install. The car would start up perfectly, then after some driving the idle would jump up and down like you're revving it slowly and would never calm down back to normal until the car is off for a few hours. No one could figure it out, i took it back to the tuner. He checked everything and said it had to be something mechanical in the car, something not connected. Make sure you check all that stuff first because it's easy to assume that it's the tune. Mine was a greddy TT HR tuned by technosquare on stock ECU.

 

This is exactly what I am experiencing on a vq35de revup S/C with vpro and uprev reflash..Also throwing p1281--trying to figure it all out

 

Still no resolve. Everything seems plugged in. This is going to take 10 years off my life lol. Any one else have any recommendations?

 

Here are a few things to try. I guess they are the same for the HR also, but I'm not 100% sure. If it's not something simple like this and everything is connected properly, i'd say it is in the tune.

Accelerator Pedal Released Position Learning
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.

Throttle Valve Closed Position Learning NBS0003A
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to learn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.

Idle Air Volume Learning NBS0003B
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:
Each time electric throttle control actuator or ECM is replaced.
Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
Battery voltage: More than 12.9V (At idle)
Engine coolant temperature: 70 - 100°C (158 - 212°F)
Park/neutral position (PNP) switch: ON
Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine
is started, the headlamp will not be illuminated.
Steering wheel: Neutral (Straight-ahead position)
Vehicle speed: Stopped
Transmission: Warmed-up
1. Perform EC-78, "Accelerator Pedal Released Position Learning" .
2. Perform EC-79, "Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
7. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops
blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the MIL turned ON.
10. Start engine and let it idle.


This doesn't address the same problem but maybe worth a shot if nothing else.
http://www.jimwolftechnology.com/wol...BILITY_FIX.PDF

 

obviously something has changed.

does it idle surge in every one of your maps? i'd get one of your maps reflashed back to stock and see if the problem goes away.

 

Replaced ECU problem solved