[sontakke]

Looks like good idea! I drilled down and it looks like extra manufacturer costs $90 each. If this scanner works, it is not a bad deal at all for people like us who only have to maintain few makes of our vehicles. Please keep us posted on your opinion of Foxwell NT510 I would love to hear how you rank it as compared to MD802.

 

[John Clark]

Well, I bit the bullet and ordered the Foxwell NT510 from Amazon Prime with 1 day delivery. I bought it based on this post, as well as the Amazon item description, and Foxwell Website that says it does bidirectional function tests.

Let's hope this works. A new throttle body is less expensive than the scan tool so if it doesn't work I'll order a new throttle body. This is mind boggling. Some say after a month or so it fixes itself but I'm not convinced. We'll see I guess. It's only money, right?

The MD802 works well but is what got me into this mess. I did the throttle body test in the service manual, looking at the Rel TB Sensor angle, which showed my throttle body was above the desired angle at idle and needed cleaning. I should have left it alone, I guess, but at 150K it was bound to need it sooner or later. I've seen cleaning recommended at half that mileage.

Why does trying to save money cost so much?

 

[John Clark]

And then there's this:

Attention: 8th Generation Civic, 3rd Generation City and Accord owners (DBW related) - 180157 - Page 2

I spent a significant amount of time researching BEFORE I did the cleaning and didn't find half the stuff I'm finding now.

 

[tkrotchko]

And then there's this:

Attention: 8th Generation Civic, 3rd Generation City and Accord owners (DBW related) - 180157 - Page 2

I spent a significant amount of time researching BEFORE I did the cleaning and didn't find half the stuff I'm finding now.

Interesting. No one in that thread, however, has explained why the system doesn't come to equilibrium over time.

 

[John Clark]

Well, I just got back from driving it about 40 miles of stop and go, highway, and freeway driving. No change. If the vehicle is rolling the idle will stay up at about 1500rpm. When you stop it will slowly come down to about 800rpm with the AC on. It should be 700 with AC on. The car will stay at 30-40mph without your foot on the gas. Very annoying.

I sure hope the TPS calibration is an option on the Foxwell scan tool and that it solves this problem tomorrow. $100 for a new TB isn't bad but I've seen reports of people replacing the TB's with new ones and having the same problem.

 

[sontakke]

I hope it works for you.

The link you provided came from a forum in Pakistan. The person who wrote it up got it from his dealer. If you want find trustworthy source, can you ever do better than Pakistan or a car dealer?

So please don't blame yourself for missing that link in the past.

 

[John Clark]

Yeah, I know it's not the most reliable information. However, it would have been enough for me to decide not to bother cleaning it. It's just strange. There's a guy on YT who cleaned his electronic TB on an Accord (looks identical to this one and on the same engine) the same way I did, bolts it back on and starts it up and it works fine. The results are just all over the place.

 

[John Clark]

OK, well I think I've figured this whole thing out. Everything that everyone reads and says on the Internet is wrong except for the one 25 year tech on the Civic forum. The Pakistani guy is also partially correct. he's correct in that cleaning a very dirty TB will give you the problems he notes (and I experienced) afterward if you don't reset the TPS data in the computer BEFORE doing a relearn procedure. He's wrong in that ONLY the dealer can do it. It does take a bidirectional scan tool, however.

I received my Foxwell NT510 today (Thank you Amazon Prime one day delivery!) installed the software on my laptop, registered the device, and downloaded my one free car software--Honda software. That all went very smooth. If anyone is interested in this scan tool I suggest Amazon as noted above.

When I plugged into the car with it I was surprised (well, not very) how it was almost identical to the Autel MD802. However, I had a lot more options in the OEM data lists than on my MD802. There was an option to reset the PCM/ECU. This is what the factory service manual says to do. However, the service manual states that if you use a generic scan tool to reset the PCM/ECU then you have to relearn the crankshaft position sensor (CKP) data after you do the idle relearn since the generic scan tool resets everything. The HDS has a special reset just for the throttle body. So, while it's nice that it has that feature I didn't use it. CKP sensors do go out occasionally so that may come in handy down the road. It's a pretty easy procedure to relearn CKP but I wanted to see if it would do it without having to go that route.

There is another menu item called TP Sensor Calibration check. I selected that and it asked if I wanted to check the TPS stored data. I said yes and it then asked if I wanted to reset the Throttle position data. It even gave a warning that said if I didn't clean the throttle body before doing this that I could experience problems. I went ahead and told it to clear the data. It quickly said it was done and for me to now clean the throttle body. That was it!

I turned off the key and then turned it back on again and did the idle relearn procedure that is found in the manual, as well as all over the Internet. 3000 RPM for two fan cycles or 194F degrees, then let it idle for 5 minutes. If the fan comes on during the 5 minutes you're not supposed to count that time toward the 5 minutes.

After doing the 3000 RPM and then closing the throttle to let it idle, my idle dropped right down to 650RPM and was perfectly smooth. I pulled up the idle learn complete/incomplete data PID and the idle learn still said incomplete. I let it idle the requisite 5 minutes (not including fan time.) Once done, I turned off the key for a few moments, then fired it back up and checked the data again. To my surprise it still said the idle learn was not complete. My thought was that it's possible this is where the VCMuzzler can screw things up. I think the computer is looking for 194 degrees on the ECT 1 for this idle learn cycle to complete as I've read numerous statements in the manual about looking for temps on ECT 1. So, rather than pull the VCMuzzler (and setting a code) I just pulled the radiator fan fuse and ran it until I got 194 on ECT 1. It was about 215F on the ECT 2 but, heck, my radiator fan fuse was burned out for who knows how long anyway. I just let ECT 1 hit 194, then dropped the engine to idle and plugged back in the fan fuse and let it idle another 10 minutes. If I were to do this again I'd remove the VCMuzzler before starting the whole TB cleaning and relearn procedure. Then once everything is done and the car is cold again, reinstall the VCMuzzler.

During the 5 minute idle time I noted a glitch on the NT510 where it was showing the low speed fan control in the ON condition the whole time even though the low speed fans were cycling normally about every minute or so. I plugged in my MD802 and it showed them cycling and showed the idle learn as completed. I plugged in the NT510 again and it showed the low speed fan on continuously and the idle learn still incomplete. I'm guessing this is a glitch in the Nt510 software, however, the perfect idle results speak for themselves. I wish I had plugged in the MD802 right after I reset the TPS data to see if showed "not completed." Maybe next time.

So, in the end, everything works perfectly now. The idle is perfectly smooth at about 650 +/-15 RPM, well within spec which is +/-50.

It is my argument that there is NO way to perform an idle learn without clearing this TP data first, either with the TPS Sensor data clearing or a PCM reset via the scan tool. My theory is that most of the people reporting on the Internet are cleaning their TB's long before 150K when I did. Mine had a pretty good build up in there and there was a significant change in airflow when I was done. If you clean it more often there won't be as much correction in the computer for the carbon build up and you may not have the problem I encountered. That's my argument as to why some have the problem and others don't. It's pretty clear to me, though, that an idle relearn can't really happen without clearing that data.

I contend that if you clean the TB regularly, like every 30K miles you probably will get very little correction in the computer and you will have no issues after cleaning. If you wait 150K like I did then the correction has to be reset. A battery disconnect does NOT clear this TPS data as I tried it numerous times--for as much as two hours.

So, while it cost me $166 to learn this lesson I'm not unhappy (though it did stress me out for a couple days.) I extremely pleased that I was able to get past it myself without having to go to the dealer. I'm sure it would have cost me $100 or so just to have them reset and relearn and so for another $66 I have a tool that does LOTS more than just a scan tool, even the MD802. It has all kinds of tests for activating components like fans, evap solenoids, AC clutch, and much more. It even has options for replacing PCM/ECU's. Additional manufacturers are only $90 so if I get in a bind and need something more than the MD802 for my GMC or my VW I should be able to have it covered for $90. Even without the specific car software it comes with OBDII preloaded so you can scan any car with it. You just don't have the OEM data unless you purchase it for that manufacturer.

There is a lot of "noise" on the Internet about TB cleaning. What I've learned is that 99% of it is wrong. I've got to try and thank the 25 year tech on the Civic forum that posted about clearing this data, as well as the guy who said he did it with the NT510. Those two posts were the solution to the problem. I just added in the detail to explain it all.

 

[John Clark]

Now that it's working normally and I'm able to watch the scan data while working normally, and it's a bit more obvious why it was doing what it was doing. Basically the TB was working just fine. The TP Sensor A and TP Sensor B don't have to be equal, as they aren't equal now.

I notice that normally when you rev up the engine it drops back down to about 1000-1100, stops, and then smoothly drops down to it's target idle speed of 650 or 700 depending on engine load (AC, lights, etc.) When I was watching the scan data graphs on those two TP sensors yesterday I would push on the accelerator pedal and let go. They would jump up, drop down, then a small jump up would happen followed by a slow decline down to the predetermined voltage. After the TP data clear and re-learn I see the same pattern but the ending idle TP voltage is lower, meaning the throttle plate is closing more.

So, basically, the TB was doing exactly what it was doing before I cleaned it but the throttle plate was still open the same amount only now letting in more air because the carbon was gone. The surge I was seeing was happening at a higher RPM but should just be the short pause in the deceleration, followed by a smooth deceleration to idle. Now that it's calibrated properly it does just that. That means that opening and closing it manually off the car didn't hurt it in the least.

Hopefully, this is all helpful to someone and I'm not just rambling. I like to understand why things are the way they are so that next time I'm smart enough to outsmart it!

 

[sontakke]

Even though I have a 1999 van, I appreciate your write up. I would be needing this fundamentals if I ever decided to touch my throttle in 2012 Acura TL.

I am seriously considering NT510 but a the last count I had about eight to ten of the various scanners :-(

 

[Our Odyssey]

Thanks for posting the detailed info. Wish these things were easier to work on! For what its worth, I clean mine out once a year as part of my maintenance routine. No issues but I do mine a bit differently. I turn the ignition key to on, put a brick on the gas pedal to open the throttle body, spray it out and turn it off, then let it sit. Start it up and no fuss, no muss. I don't know if that's the 'proper' way to do it but it works for me.

 

[John Clark]

That's one method I've seen. However, the factory service manual specifically says to remove it for cleaning and to NOT spray cleaner directly on the TB. There is molybdenum grease on the shaft bearings that they don't want removed.

As far as whether you do it using the brick method or the removal method it really doesn't matter for calibration. It's a safety issue. If that brick slips off or something happens and that plate closes it will take your finger off. It's a VERY strong motor and, from what I've read, has an ice break mode where it's strong enough to break ice if it thinks it has built up. I think what matters on the calibration is how much it has built up when you clean it. If you clean it yearly then you're never getting enough built up for the computer to correct for it. Subsequently, when you clean it you're not really removing enough carbon to change the calibrated airflow. Yearly might be the best method if you don't have the scan tool to reset the TP sensor data. If you do it that way, though, I'd recommend not spraying cleaner directly on the TB plate and shaft. Wet your rag and just use that to wipe down the TB. That's how the manual says to do it and it cleaned mine up quite easily using that method.

 

[John Clark]

...I am seriously considering NT510 but a the last count I had about eight to ten of the various scanners :-(

Yeah, I hear ya. I have an Innova 3130 that I've had for 6-7 years and it has worked well. It's easy to use and shows live data for generic OBDII. However, recently I decided I wanted a better scan tool and after much research I decided to purchase the Autel MD802. It's a nice scanner that does OEM data for pretty much all makes and models but has no bidirectional capability. Since usually that capability is only found in $800+ scan tools I decided the MD802 was the best for what I could afford.

Once I got that I found all kinds of things I could do with it, including checking the throttle body relative position which checks for carbon build up in your TB. I found I was almost double the spec TB angle given in the service manual so I decided I better clean it. That's how I got into this whole mess.

That's when I found the post about the NT510 having the capability and with a low cost. However, the MD802 cost me $235 and the NT510 cost $171 with shipping so I'm at close to $400 in scan tools just in the last few weeks. The Autel DS708 is a full bidirectional tablet scan tool that does most all the manufacturers and is what I originally wanted. Only problem is it's $800-900 and $500/year for updates if you need newer year model vehicles. If I add another one or two vehicles to the NT510 I'm getting close to that DS708 price range.

So, in hindsight I should have just bought the DS708 that I wanted and had all my bases covered. It was just hard to justify at the time.

However, for those who don't have one and are looking for a scan tool for their personal cars I highly recommend the NT510.

 

[maxud]

JC,
just super great stuff here!
I follow your logic to the T.
If I get my ds708 going, you know the first thing I am doing is ripping that throttle body off
Sorry to hear that my ultimate recommendation for MD802 got you in this trouble, but
we new upfront that it was not capable of bidirectional communication.
Glad the issue is solved though.
Max

 

[John Clark]

JC,
just super great stuff here!
I follow your logic to the T.
If I get my ds708 going, you know the first thing I am doing is ripping that throttle body off
Sorry to hear that my ultimate recommendation for MD802 got you in this trouble, but
we new upfront that it was not capable of bidirectional communication.
Glad the issue is solved though.
Max

No worries, for what it does it's still a good buy. It has the capability to scan many cars for OEM data. I'm half way into the cost of the DS708 is all now with the NT510.

Yeah, if you have a bidirectional scan tool the throttle body cleaning is no big deal. Without one you may want to think twice about it if there are no driveability issues. That said, my idle is smoother than it was when I first checked it with the MD802 while looking at the RPM and Rel TPS Sensor angle. It was closer to 700 and was up and down more. It's right on the 650 now and +/-around 15-20RPM so there was definitely an improvement after cleaning...not something most would notice just driving the car but I noticed via the scan tool.

 

[sontakke]

To be perfectly honest, cleaning throttle body is pretty much exercise to make one feel good about it. Unless it is fully coked on, the airflow through it would have marginal improvement. You are changing the diameter from (say) 2.000 inch to 2.001 at the best by removing that carbon. Even if you get 0.1% more air, that is going to happen at Wide Open Throttle. We can count the number of people on one hand who routinely floor the gas pedal on their Odyssey.

Go ahead, tell me I am all wet but give logical reason why.

 

[maxud]

To be perfectly honest, cleaning throttle body is pretty much exercise to make one feel good about it. Unless it is fully coked on, the airflow through it would have marginal improvement. You are changing the diameter from (say) 2.000 inch to 2.001 at the best by removing that carbon. Even if you get 0.1% more air, that is going to happen at Wide Open Throttle. We can count the number of people on one hand who routinely floor the gas pedal on their Odyssey.

Go ahead, tell me I am all wet but give logical reason why.

I am not going to say you are wrong in general speak, however some throttle bodies have built in IACV's and EGR passages
that tend to get clogged with time. I don't know specifically with Odyssey setup, but I have done other throttle bodies that
definitely needed cleaning, beyond just feeling good about the act itself.

 

[John Clark]

To be perfectly honest, cleaning throttle body is pretty much exercise to make one feel good about it. Unless it is fully coked on, the airflow through it would have marginal improvement. You are changing the diameter from (say) 2.000 inch to 2.001 at the best by removing that carbon. Even if you get 0.1% more air, that is going to happen at Wide Open Throttle. We can count the number of people on one hand who routinely floor the gas pedal on their Odyssey.

Go ahead, tell me I am all wet but give logical reason why.

I actually agree with your first sentence. I had no driveablity issues and should have left it alone. However, the book does give a spec on TP angle at idle to know when it should be cleaned. That spec is "less than 2.54 degrees. Mine was at 4.5 degrees at idle. After cleaning and calibration I'm at around 1.5 degrees. That's actually a fair amount.

I agree that the airflow at WOT would be virtually unaffected by a dirty TB, however, airflow at idle can be affected. Remember that there are angles involved on a round throttle plate. When you open the throttle plate more you actually open it a lot more on the sides for only a little more at the bottom. Theoretically, eventually you'll end up with idle issues especially since the TB is programmed to decelerate the engine in two steps. It drops it down to 1000 then stops and then slowly drops to low idle. If the carbon is building up at the top and bottom then the throttle plate will have to open more and more and eventually will be open a lot at the sides instead of the top and bottom.

That's my theory and I could be all wet, as well. I think cleaning it every 15-30K miles is definitely overkill but even cleaning it at my 150K might have been unnecessary. However, it does idle smoother than before.

 

[John Clark]

I am not going to say you are wrong in general speak, however some throttle bodies have built in IACV's and EGR passages
that tend to get clogged with time. I don't know specifically with Odyssey setup, but I have done other throttle bodies that
definitely needed cleaning, beyond just feeling good about the act itself.

There are no IACV passages or EGR passages near the throttle body on this vehicle. In fact, the electronic throttle body takes care of the IACV duties so there is no IACV, meaning one less part to clean or go bad. The cleaning needed was just around the throttle plate and would only affect opening and closing of the throttle plate.

 

[John Clark]

...You are changing the diameter from (say) 2.000 inch to 2.001 at the best by removing that carbon...

I didn't measure it but there was a good 0.010 to 0.015" of carbon right where the plate meets the body, all the way around. It was built up pretty good. The throttle body motor is very strong but you don't really want anything to impede the movement or make it stick closed if you can help it. I'm sure it's possible to strip the gears in there as I saw on on a YT video from Briansmobile1. He's not working on a Honda but I'm sure the TB's are similar: