Finally found out why my RPM's were all over the place

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Fire0nic3

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Just this past week I noticed my RPM's would fluctuate and were all over the damn place. Even during idle the RPM wouldn't stay steady. I also notice throttle lag (sort of). I was kind of stumped on what it was though until I came across a writeup on myg37.com. Someone on there had a similar issue on their G37. What he did was clean both throttle bodies. So I cleaned up mine this morning. I purchased throttle body cleaner at the dealer, and bought some microfiber towels to be gentle on them since the throttle body is delicate. I cleaned both the left and right side. Boy were they filthy as hell!! My 09 FX35 has 28K miles on it, and some recommend to clean the throttle body every 30K miles. So that sounds about right. After cleaning the throttle bodies you have to perform the idle relearn procedure too. So don't forget that!

What a difference it made!! No more fluctuation's. It idle's sooooooooo smooth. Throttle response is precise and right on tap like it should be.


I notice someone else had this problem too. If you do, have your throttle body cleaned or do it yourself like I did.

Oh and I forgot to mention that if your using those K&N drop in filter's, you better clean your throttle body more often. I've heard many complaints about the red oil that K&N lubricates the filter's with can sometime's be sucked up in the throttle body and dirty it up with that oil. That's why some don't really recommend them. I can't confirm if that's true or not, but it may be something you might want to look in to.
 
Fire0nic3 said:
Oh and I forgot to mention that if your using those K&N drop in filter's, you better clean your throttle body more often. I've heard many complaints about the red oil that K&N lubricates the filter's with can sometime's be sucked up in the throttle body and dirty it up with that oil. That's why some don't really recommend them. I can't confirm if that's true or not, but it may be something you might want to look in to.
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Just make sure you do not use too much oil after cleaning the filter. The oil can mess up the maf sensor and dirty up the intake system. I myself only use dry filters like the aem dryflow.
 
fxlr8 said:
Just make sure you do not use too much oil after cleaning the filter. The oil can mess up the maf sensor and dirty up the intake system. I myself only use dry filters like the aem dryflow.
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I'm not using the K&N's no more anyways. For the money I didn't see no slight performance difference, better sound, or improved fuel economy. I just saved myself the headache and switched back to OEM. :tup:
 
How to reset your ECU and perform the Throttle Pedal Release and Idle Air Volume Learning procedures on an Infiniti FX35.

Before attempting any of the following procedures, it is advisable that you read through the instructions thoroughly and familiarize yourself with them.
A stop watch or an analog clock with a second’s needle will be useful.
**a quick reset can be accomplished by disconnecting the negative battery terminal, and depressing the brake a few times.
ECU Resetting Procedures
Timing is extremely critical. If it is NOT DONE within the specify time, the ECU will not reset and the Check Engine Light (CEL) will continue to remain ON.
Operations Procedures
1. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.
2. Repeat the following steps (2a and 2b) procedures quickly five times within 5 seconds.
2a. Fully depress the accelerator pedal (HARD).
2b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the CEL starts blinking.
4. Fully release the accelerator pedal (while the CEL is still blinking)
5. Wait about 10 second.
6. Fully depress the accelerator pedal and keep it for more than 10 seconds.
7. Fully release the accelerator pedal (The CEL light will continue to blink).
8. Turn ignition switch to “OFF” position and now you can start the car. The CEL light should be gone.
If the CEL light continues to remain ON, repeat the above steps. Timing is EXTREMELY critical to resetting the ECU.
Accelerator Pedal Release Position Learning
Operation Procedure
1. Make sure that the accelerator pedal is fully released.
2. Turn ignition switch “ON” and wait at least 2 seconds.
3. Turn ignition switch “OFF” wait at least 10 seconds.
4. Turn ignition switch “ON” and wait at least 2 seconds.
5. Turn ignition switch “OFF” wait at least 10 seconds.
Throttle Valve Closed Position Learning
Operation Procedures
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch to “ON”.
3. Turn ignition switch to “OFF” wait at least 10 seconds.
Make sure that the throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume Learning (Throttle Position Learning)
It is better to count the time accurately with a clock. 1. Perform “Accelerator Pedal Released Position Learning”.
2. Perform “Throttle Valve Closed Position Learning”.
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch “OFF” and wait at least 10 seconds.
5. Confirm that the accelerator pedal is fully released, then turn ignition switch “ON” and wait 3 seconds.
6. Repeat the following (steps 7a, 7b) procedures quickly five times within 5 seconds.
7a. Fully depress the accelerator pedal (HARD)
7b. Fully release the accelerator pedal.
8. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 20 seconds until the Check Engine Light (CEL) stops blinking and turned ON.
9. Fully release the accelerator pedal within 3 seconds after the CEL is ON.
10. Start engine and let it idle.
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure the idle speed and ignition timing are within the specifications.
__________________
 
Is it SAFE to play with the throttle body. I heard if you mess up the TB you gonna have lots of problems such as idle timing. so how you clean it?
 
mrlerry said:
thanks fireonic!

for those that were confused how to clean the throttle body and wanted pictures, myg37.com had a nice write up
http://myg37.com/forums/d-i-y-installations-modifications/203765-clean-your-throttle-bodies.html
Click to expand...


hehe I was about to post that link:rofl:. Are your RPM's all over the place?

It's a good writeup. Their doing it on the VQ35HR motor in that DIY guide.

The dealer wanted to charge me to do this cause they said it was a regular maintenance thing, which it is cause it gets dirty itself on any car. I think they quoted me like $150 to do it. Usually I'd just save myself the headache and have it done their in case something get's screwed up their liable for it, but I knew how to do it myself already. I suck at do it yourself things, but cleaning the TB was pretty straight forward:tup:
 
I just cleaned both of my throttle bodies today again myself, and 2.5K miles later they were oddly dirty again. It seems like on the HR motors they get dirty pretty quickly. Got to run to Autozone again to buy some throttle body cleaner.:tup:

---------- Post added at 05:10 PM ---------- Previous post was at 05:05 PM ----------

I forgot to add that if you don't disconnect the throttle position sensor when cleaning the throttle bodies, you don't have to perform the idle relearn procedure.
 
Rubare said:
is it the same procedure for 03-08?
Click to expand...


Probably similar. Only thing I can think of is that the 2nd gen has two throttle bodies since it has two intakes, and the 1st gen only has one throttle body. Cleaning it should be the same procedure, just don't mess with the butterfly valve.
 
I replaced the battery on my '04 G35x about 6 months ago. When I started the car, the rpms held around 2K and gradually dropped to about 1500 in about 5 minutes... rpms wouldn't go any lower that.

After searching on a G35 forum, it was advised to clean the throttlebody to fix the rpm issue. I was very skeptical but I didn't feel like doing the TB relearn procedure so I tried it. It actually worked and brought my rpms back to normal. It's a mystery, I know. *shrugs*

It was recommended that when you clean the TB, you may want to disconnect the negative battery cable as this would purportedly keep you from having to do the relearn procedure. I'm like Fire, don't move the butterfly and you should be okay but in the event you accidently move it, the disconnected battery is supposed to keep the TB within TPS parameters.... supposedly.
 
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