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Discussion Starter · #1 ·
Hello everyone.
I got a P0507 (unexpected high idle, usually a vaccum leak) code a week or so ago, a few day before I was planning to do the timing chain guides on my 2006 Frontier.
So during the down time for the timing revamp, I took off the throttle body and cleaned it. It was pretty filthy. I sprayed Brakleen on my rag, then wiped out the bore of the TB until it was shining like new. During this process, I also was manipulating the butterfly around (open and close). I also put in a new PCV valve at this time, just for fun.
When I got the engine back together (timing job came out great) it had a high idle, and the code came back. So I did the necessary re-learn procedures that are well documented on here and other places on the web. So far no success. Somtimes it idles at 1200 and sometimes it will go to 800.
I am monitoring live engine parameters with my scan tool. Ign timing is about 5degress, which is retarded from its spec of about 15 (probably the ECU is trying to get idle speed down by retarding). Throttle position is 3.9%.
I have a suspicion that the throttle body cant close it any more than 3.9%. With the key-on and live data streaming, I can push the butterfly close to 0%, but it springs right back to 3.9% (a strong spring). Not sure if this is normal...
I have visually inspected for vacuum leaks and things look solid.
So long story short, did I permanently damage the TB when I was cleaning it? Is 3.9% minimum TPS OK? Why did I get this code BEFORE I cleaned the throttle body?
I consulted with a friend who works at an Acura dealership and says he has never heard of damaging a TB by open/closing by hand during cleaning. And he has done A LOT of them.

Any advice/guidance is appreciated.

Truck has 170k miles
Auto trans, V6 engine
Overall runs good except for this high idle
 

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Discussion Starter · #4 ·
I have purchased a replacement throttle body and hopefully that will get the idle down and keep it happy. Will update after install and testing.
 

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Discussion Starter · #5 ·
Ok. So new throttle body had zero effect. Back to Amazon it goes.

Here is the deal. Whenever the throttle body is unplugged, removed or cleaned you will have to do a re-learn procedure.
Symptoms that the throttle body has been "unlearned":
1. High idle, between 950 and 1200 rpm.
2. SES light - P0507 Unexpected idle value.
3. Hard downshifts(automatic)
4. Very high revving at fire up (2300 rpm approx).
5. Ignition timing at idle stuck at 5 deg BTDC.

Solution:
Follow the idle relearn procedure as documented by Nissan. It is easily found on this forum and elsewhere.
The idle volume learning procedure may have to be repeated MANY times before it finally works. You will know when it takes because the final step is "start engine" and when you do this it will idle so low it almost dies. Then wait 20 seconds and you will see a big difference. Clear the SES codes and you are good.

MYTH:
Opening and closing the TB blade by hand (while it is off the engine) destroys the electronics.
This is not the case at all. I opened and closed mine many times when I was cleaning it.

Good luck. And when in doubt just keep repeating the relearn procedure.
 

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I had the same thing happen to me when I replaced the radiator & plugs on my '06 before I traded it for my '13. I tried the re-learn procedure probably 20 times & no luck. I finally gave up & called the dealership I bought it from & they told me to bring it down.

They took it back into the shop & about 20 or so minutes later it was done. When I asked the service guy what happened he told me "as long as you DONT move the butterfly-valve or turn the key to the ON position while the TB is out or disconnected, everything will be fine". He also said that if you don't do the re-learn EXACTLY correct, the ECU gets all freaked out & starts doing all sorts of weird things.

The solution to the problem?? Nissan connected the truck to their CONSULT program & either did the relearn procedure with it OR wiped out the memory & reset the ECU back to its initial state. I'm almost certain the service guy told me they just reset the ECU then checked to make sure there were no other problems. Shoot, he said they went ahead & did the 2* timing bump for me while they had it connected! To me, it was $150 or so well spent. :smile:

I believe him 100% about NOT messing with the butterfly-valve because I've taken the upper plenum off my '13 a few times & made damn sure I did NOT touch it. And, every time I put it back together it ran the same way as before I took it off.

My suggestion is if you can safely drive the truck to the dealership then go ahead & take it to them & let them hook it up to their system & reset your ECU for you.
 

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This thread makes interesting reading. I wonder if a DIY TB cleaning could be performed by having someone in the driver's seat with engine running while another person sprays the TB cleaner? If the engine threatens to stall, the person in the driver's seat could gun the engine as needed. The TB wouldn't be messed with by hand and after a few tries, I'm guessing that the team could do the job.

Has anyone tried this? It's just a thought.

My '06 (@ 145,000 Miles) has an intermittent lumpy idle on start up that quickly clears away and I was wondering what it might be.
 

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Discussion Starter · #9 ·
If you have a dealership in your area and you have a daytime job that allows time for you to do that.....
 
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