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And that could possibly be why you never had a problem. If you cleaned them early and often, then perhaps the range of relearning adjustment was always within ECU specs. The problem may only occur when the differential is too great for the ECU to handle. I think it's easier to believe there's no risk until you've seen one that just doesn't behave.
In general, I have to disagree that this is a rare phenomenon. If you look through the threads on this and numerous other forums, there are many people that experience this issue. I remain unconvinced that it is a totally "safe" thing to do, at least to the extent that it should be recommended without some reservation. It's NOT that I don't think TB's should be cleaned, just that people need be well aware of what CAN happen, and well prepared to address the consequences if they do end up being one of the unlucky ones.
.02
Don't get me wrong, i'm not saying there's no risk. I get there's risk for things to go wrong with most of the work you can do to a car yourself these days. I'm just saying that if he has a legitimate need to actually clean his throttle bodies he probably shouldn't put it off just because of this thread.
As for my case, who knows. I always went in and cleaned when my idle started hunting (typically 3 if not 4 times a year). I flashed to the latest ROM last year (was hoping to resolve my transmission stutter) but before that and after that i've never had an issue.
Hello,
I bought a 2007 G35x premium automatic sedan with 155kkm last Sept. I cleaned the throttle bodies and suffered the idle hunting for a month but finally resolved it with troubleshooting and access to the FSM (NICO website). I tried the relearn procedure and eventually went to the dealer but they coudn't effect a relearn and quoted $2k for new TBs. I declined and convinced them to update the ECU but it still woudn't relearn. The FSM details acceptable voltages for open and closed throttle positions and I was able to backprobe the TB harnesses to confirm. I then adjusted the external setscrews so that the throttle plates were closed but not binding. I removed each TB plastic cover and backed off the internal setscrew in an attempt to increase the voltage range ( and avoid any binding). When I started the car the idle settled down immediately, without any pedal dance! It was such a relief! Took many hours of research and troubleshooting but from other stories on this forum, I was convinced a simple TB cleaning did not destroy them.
Steve.
Last edited by bsmooth; Dec 27, 2015 at 07:25 AM.
Reason: spelling
Did you get the idle to 600 rpm? Cant believe your car was unable to relearn after the ECU update... thought that was the end all fix. Glad I didnt waste money than.
Hello,
I bought a 2007 G35x premium automatic sedan with 155kkm last Sept. I cleaned the throttle bodies and suffered the idle hunting for a month but finally resolved it with troubleshooting and access to the FSM (NICO website). I tried the relearn procedure and eventually went to the dealer but they coudn't effect a relearn and quoted $2k for new TBs. I declined and convinced them to update the ECU but it still woudn't relearn. The FSM details acceptable voltages for open and closed throttle positions and I was able to backprobe the TB harnesses to confirm. I then adjusted the external setscrews so that the throttle plates were closed but not binding. I removed each TB plastic cover and backed off the internal setscrew in an attempt to increase the voltage range ( and avoid any binding). When I started the car the idle settled down immediately, without any pedal dance! It was such a relief! Took many hours of research and troubleshooting but from other stories on this forum, I was convinced a simple TB cleaning did not destroy them.
Steve.
That's an interesting experience, and I agree that a simple TB cleaning should never destroy the TBs. However, I remain convinced that the real issue here is always the ECU's basic (in)ability to perform the relearn correctly, and not any fault of the TBs. Given that, I'd be hard pressed to suggest to anyone that they open up their TBs and start messing with set screws. Remember, there are reported cases where the dealer, having initially claimed both the TBs were bad, replaced them only to find that the ECU STILL could not complete the relearn, and then subsequently replaced the ECU before achieving success.
My theory is that the ECU has the ability to handle some idle deviation, but only within a certain range, from which, it can bring it back into idle spec and complete the relearn procedure. Thus, if your TBs are significantly dirty, and cleaning them caused a large increase in unthrottled airflow (making the idle surge), the ECU just sh%ts the bed and cannot complete a relearn. Maybe specific revisions of the ECU are coded to handle a broader tolerance of unthrottled air, but even with that, there is still the potential for that tolerance to be exceeded in the worst case scenarios.
This also supports the workaround methods adopted by some shops to cheat the ECU into learning in stages (i.e. they pull the plug on a few injectors, starve the fuel supply, and artificially drop idle down to a range where a relearn can complete; then repeat the relearns over and over until they can keep the idle backed off as the injectors are all reconnected again in stages).
Thanks for the info, I will leave my car unplugged for a day or two and see if that will help first. Then keep trying the relearn. If I get fed up I will bite the bullet for the ECM reflash. Called the Nissan dealer next to my work and they wont touch Infinitis.
doesn't make sense that they don't touch infinities being it's basically the same a the z.. thats really weird.
Lights, radio, heat/ac is there anything else?
QUOTE=coffeysm;7020909]I've had some Nissan dealerships tell me to go to an Infiniti dealership before. Most likely they were owned by the same person or something.
I had this happen a couple of years ago when I cleaned my throttle body. I had to do the pedal dance like a million times to get it to work correctly. You need make sure all electronics are off and once it drops down to regular idle speed, turn it off, and back on again right away. I don't think those steps were mentioned in the DIY's I read.[/QUOTE]
Just cleaned mine....now I got the idle hunting going on....been trying the pedal dance to no avail...... going to drive it to work tomorrow and try some more when I get home
07 sedan base model
I had the same issue. Ended up needing to get the ECU re-flashed by the dealer. Was $200 (yeesh!).
I hear that Nissan dealers can do it too, and may be less expensive.
I did my best to achieve the pre conditions outlined in the FSM before/while doing this as I have also continue trying the pedal dance every now again hoping that might accidentally work.
The app is green lit and when i press it, it says something like ECU busy...... and numbers continually counting up....
You're not meeting all the conditions for the reset, read the FSM again, you need to meet EVERY CONDITION for it to work.
-Battery voltage 12.9v or greater
-Engine coolant temp between 158F - 221F
-PNP switch ON
-Electrical load switch OFF (this is the one most people **** up, turn off EVERYTHING IN THE CAR, stereo, climate, seat heater, EVERYTHING. I'll repeat again, turn it OFF, not just the fan on low speed, turn the entire climate control panel OFF)
-Steering wheel switch NEUTRAL POSITION (this is another one people commonly **** up, yes that means 100% straight, not 1 degree to the left or the right, COMPLETELY STRAIGHT)
-Vehicle speed STOPPED
-Transmission warmed up (pretty sure it's 105F or greater, it's 0.9v or less for ATF temp sensor 1)
If you don't meet EVERY SINGLE CONDITION it will not reset. The elec load switch won't be OFF if your foot is on the brake pedal either since it's illuminating the rear taillights.
If you have a DRL system you can disable it by setting the parking brake BEFORE starting the engine.
