Why Does A Dirty Throttle Body Cause Stalling Problems

Does your car randomly stall when coming to a stop? Do you have MAP or MAF out of range codes with no other driveability problems? A dirty throttle body could be your issue.
Related videos:
1. 2014 Chevy Malibu 2.0L P1101 Caused by a Dirty Throttle Body
• 2014 Chevy Malibu 2.0L...
2. Dirty Throttle Body-Identification and Cleaning
• Dirty Throttle Body-Id...
3. MAP Sensor Code P0106 caused by a dirty throttle body
• MAP Sensor Code P0106 ...
00:00 - Chapter 20, page 12 of my book
02:00 - what's the parts changer going to do?
02:50 - false MAP code P0106
03:30 - scan data before and after
05:40 - P1101 code
08:02 - idle load compensation
08:54 - throttle body damage
09:22 - how to open an electronic throttle plate
10:56 - idle relearn procedures
ScannerDanner Tools:
www.scannerdanner.com/tools.html
www.amazon.com/shop/scannerda...
For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
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On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!
Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[@titaniumman_22]

The knowledge shared by Paul is immeasurable. I am out of town for 2 weeks with sad cell service area, but when I get home, I will be supporting him by buying his E-book and then upgrade to the hardcopy. I am excited to read and learn more on the diagnostic end! 🇺🇸

[@ScannerDanner]

Thank you so much!

[@juanramon10-14]

I have the paper one. Is a good investment

[@BigDog50001]

Still waiting for my ScannerDanner pocket screwdriver so I can look cool walking around the shop! 😂

[@jarinwilson9539]

One of these days we will all have a holographic Paul Danner available to us, just don't show up unexpectedly 😂

[@maximusvonce1381]

My highly modified supercharged Boss Roadrunner Mustang kept stalling coasting to a stop, and then it wouldn't start up without giving it gas. Took twin blade throttle body off and the backside of blades were all gummed up. Cleaned it spotless and car starts on first crank and stalling is gone. This video is Absolutely correct.

[@ScannerDanner]

Awesome! Nice job on your part

[@isalmankhan1]

This is AWESOME👍🏻 LOVE THE LECTURE😍 THANKS FOR SHARING SD👍🏻 STAY BLESSED🙏🏻

[@kiknlif]

You are a wealth of knowledge and very articulate. Thanks for sharing all this information with everyone.

[@joefeatherstone9646]

Great information. I always wondered why a dirty TB would affect how it does. Thanks

[@Pablo_Automotive]

Thanks Paul for another great explanation

[@nancylewis7142]

Thank you for this information.

[@mummaistvan7320]

Thank You !!!! I needed to hear your words of wisdom today! I shared with my husband and 3 kids . Thank You from the entire Family 😊

[@Troy_Built]

I had a dirty throttle body cause a no crank a couple of weeks ago. That was a first for me. 2007 Corolla popped a code for throttle stuck open. After reading through forums and KZbin videos. They all seemed to say a dirty throttle body was the cause. I took it off and cleaned it. Once I reset the codes it started right up. It also tripped the MAP code an hour before that.

[@GeminiSeven43]

Great video Paul and Caleb and very good info. I think that the myth of losing a finger in a throttle body are not from the force of the throttle body motor but by the natural reaction to pulling your finger out once it is clamped down causing the real damage. Thank you so much for showing these videos and showing others that caution needs to be taken when dealing with these type of units. Take care and have a great day.

[@fredflintstone8048]

It won't cut your finger off, but rather will make it hurt so bad that you think it might have been cut off.

[@johnentinger6524]

i have been cleaning throttle bodies since 1984. i wish i had the scan tools back then like you have now. you explained this in simple terms. this is the main problem ,egr valves also cause stalling low idle. worst i have ever seen was my daughters (uses oil). I scooped gunk out from behind the plate. another indicator is watching how fast the engine speed slows on a deceleration. they usually fall faster than normal. glad to see you educating our youth. thank you

[@m.b.smoshitoa8325]

So far, I don't care what video you upload I just start by liking it Moshitoa 🇿🇦

[@moparnut6286]

I just diagnosed and repaired a 2011 impala ETC with a Zurich ZR15 and it had the capability to relearn the ETC and do all the sweeps....this video confirms all my thoughts. And cleaning failed and I replaced the ETC....kevlar gloves can protect your hands during working with the ETC... Your awesome Dan! Just in time!

[@ScannerDanner]

Thank you! Oh and my name is Paul Danner :-) But I get "Dan" all the time lol

[@alrifainidal]

very nice information thank you very much

[@xj31]

I would say that dirty throttle bodies still cause stalling, but not like they used to. They do a better job compensating for it these days. Back in the late '80s it was a huge problem

[@ScannerDanner]

it is still a huge problem! Check out the related videos I put in the description

[@ferrarimatt1]

On 2015, the mitsubishi outlander Sport se vehicle idle would go high and low at idle speed act like a vacuum leak . No trouble codes found clean throttle body problem went away vehicle had 50k miles on it. Bought the vehicle new.

[@franciscoxaviergonzalezrom4648]

Thank you!

[@matthewazzopardi5369]

I love your videos mate and i started reading the ebook i just purchased and i love it

[@ScannerDanner]

Thank you so much! The lessons (like this one) really make the book come to life.

[@matthewazzopardi5369]

@@ScannerDanner 100%

[@user-up7lj3lk2c]

I like this channel

[@ScannerDanner]

Thank you!

[@dfields9511]

Great explanation. I had a nissan maxima v6 (vq30de) engine . Randomly would idle strange at times. What fixed it was a idle air volume relearn procedure

[@ScannerDanner]

Those relearn procedures where do odd on some Nissan systems

[@dfields9511]

@@ScannerDanner yah, like unplug the throttle body while it’s running and reconnect within 5 seconds after the car is warmed up. That’s a Hitachi throttle body on nissan.

[@Jpilgrim30]

I’ve cleaned probably hundreds of throttle bodies over the years. I always open the throttle by hand and have never had an issue from it. Nissans are the worst for resetting the idle. I had one that I had to disconnect 3 injectors to get the idle speed low enough that the relearn would complete.

[@jeremybrewer3289]

Depends on the manufacturer Paul. I work for Mazda. With Mazda you can open with your finger and hands all day. It automatically resets when you restart the car. If I have a dirty throttle body causing issues which I did just other day on a 2011 Mazda 6 DTC of P0101 MAF code. PID data shows g/s at 5-5.5 at idle with a 2.5 liter engine. This vehicle should be like 2.0-2.8 at idle. Had an aftermarket MAF so I checked this out first. Then opened body and it was crusty like a coal mine. So I remove them. There is only a few bolts that hold them on and remove the snorkel pipe. I take a toothbrush and carb cleaner. I spray the tooth brush and scrub. I also take a red sos pad on the stubborn areas. Which is fine for machine metal. Just dont go crazy on the light sanding. As for spray I dont spray directly inside. We do not have issues like that. Just making a point that in my experience depends on manufacturer. Mazda push on them on you want. Wont hurt them. Some will require a relearn which is simply idle it for 30 sec. Go through gears then do again with all loads on back to P and restart car. Idle will come back up to normal RPM range.

[@aymenmohamed1134]

Awesome

[@IlianNachev]

Paul, Your videos are gems! You explain issues so well that even a layman can understand and that shows how well you know your stuff to be able explain it the way you do! I have a ‘95 Mitsubishi GTO (same as 3000GT) that exhibits dirty throttle body signs (start and immediate shut off, followed by a hard start; very low idle at times, engine does not rev itself up on warm start, etc.). It only happens on warm/hot start. It seems to work better with the AC on. I cleaned the throttle body with carb cleaner and replaced the idle control valve, but the problem persists. The only way I was able to go around it was to raise the idle speed through the so called BISS screw, while following Mitsubishi’s procedure for setting the idle speed. That way, when the idle drops at times, it never drops too low. Since my car has an auto trans, the car usually idles at different speeds when in “Park” and in “Drive” as it is lower when in “Drive.” Could the throttle body’s shaft seals be worn out, leaking air and that way introducing a vacuum leak, causing the low idle? I already replaced the o-ring of the BISS screw as the old one was rock hard and split… The “low” fuel trim was maxed out positive, so I added 20% fuel to it, in order to bring it back, closer to zero. Fuel trim “High” has settled to 92 (Mitsubishi reads the fuel trims a bit different than other brands, where “0” is “100” and that way there is no negative sign in front of the number when the trims go in the negative… At the moment, the MASS airflow sensor shows airflow of 46 at idle, while I seem to remember that it used to read 34, before I raised the idle speed. The timing is at 14-15-16 at idle. I am not sure if that is the proper way to fix the problem I had, but it seems to be working for now. I used to get 505 trouble code before I added more fuel to the fuel trim “low,” and after I added fuel, the check engine light is constantly on, but my scanner does not show any codes. I have set the TPS to be at 13%. Am I on the right track, or do I need to do something specific that I am missing?

[@ScannerDanner]

I dont understand what you mean by you added 20% fuel to it? Is there an aftermarket programmer on this? 20% postive fuel trim at idle does suggest a vacuum leak Thank you!

[@IlianNachev]

@@ScannerDanner, I have a programmable ECU so I can change the values. There is a fuel table, called VE Smoothing Table that can be used to modify the values of the fuel trims… I suspected a vacuum leak, but I fixed all of the ones I found and still no difference. That is why I am suspecting the throttle body shaft seals. Or could it be that I did not install the valve stems seals well, when I was rebuilding the heads, and they leak? Thank you so much for responding!

[@ScannerDanner]

@@IlianNachev there is a lot of possibilities for what you have, especially when modifications have been done. Does your lean condition improve as you raise the RPM in park to 3000? Or is it about the same? If it improves, this suggests a vacuum leak, if it is about the same or gets worse, we move away from a vacuum leak

[@IlianNachev]

@@ScannerDanner, The values improve when raising the RPM, yes. Once the car starts idling is when they go up again… I will keep looking for vacuum leaks! Thank you!

[@ScannerDanner]

@@IlianNachev don't forget about your brake booster and also the pcv system. Pinch off the booster hose while watching O2 and STFT. Do the same for the PCV valve and purge valve for the EVAP system.

[@ricardooconnor2362]

Hey Paul, how are you brother? I had a dirty throttle body a few years ago and yes it does cause stalling problems. It also cause idling and acceleration problems. I cleaned it myself with, I believe, a carburetor cleaner, reset the idling to factory and it was good after that.

[@ScannerDanner]

For sure, the initial step in of the throttle in particular. Thanks!

[@aleskyfinis1025]

Like videos good afternoon

[@bbmd2200]

Hey, Paul. I was trying to troubleshoot a p0101 on a Nissan Quest yesterday. I looked at the maf calculated load at idle, it was 40 and sometimes 70. I concluded that the maf was overreporting the airflow. Today, the tech diagnosed it, and suggested replacing the sensor. He replaced the sensor 3 times before he found a good one because all the sensors were causing popping noises through the intake. He even thought that the cat was restricted, which I didn't think was the case after following you for a long time. If an engine cannot exhale, it cannot inhale. Less air in means less grams per second or calculated load. As far as the dirty throttle body, could you use the tps voltage if you don't have a percentage PID as a higher voltage would suggest a dirty throttle body?

[@garyradtke3252]

I don't know if this is true for any other manufacturers but Mercury Marine use mostly GM throttle bodies on most of their sterndrive and inboard engines and they cautioned against manually open the throttle plate do to the throttle motor becoming a generator and back feeding the system. I have mistakenly done it with no apparent harm but I do disconnect the TB plug (most of the time).

[@ScannerDanner]

I've hear something about the plastic gears internally being damaged by manually opening them. I've done so many without issues, but I try not to use the manual method unless I have to. Thanks!

[@wrightsrrt871]

So I have an good question for you might make an good topic! On the 2011 jeepgrand cherokee wk they are common to have p0563 battery system voltage to high which is common to an bad alternator, battery or open/short in system! Client has replaced alternator and kept doing it then someone used an external electronic box to bypass the alternator the the fuse relay panel but code still came back alternator and battery are showing good but I found an interference ground strap not hooked up and just hanging and but connectors on the work for box where not shrink wrapped and such have you heard of these systems cause the battery is located under passenger seat and there are extra contact points to deal with than normal? Thanks for your time!

[@ScannerDanner]

These are known for bad alternators and bad ECM drivers for the alternator. I have a case study on a 2011 Jeep with this one my website. www.scannerdanner.com/scannerdanner-premium-chapters/battery-starting-charging-systems-troubleshooting/788-2011-jeep-liberty-alternator-field-control-and-pcm-driver-problems-part-1.html

[@wrightsrrt871]

@ScannerDanner thanks for the information much respect for your knowledge and help!

[@samwisegamgie8163]

If I was near your school I would have you use my car for your class. It has stalling issues, not wanting to read the O2 sensors, extended crank time, and randomly misfiring on random cylinders. I have a 2010 Chevy Aveo.

[@ScannerDanner]

extended crank times makes me want to verify fuel psi as a starting point, especially because you mentioned O2 sensors not reading properly and random misfire codes

[@georgebell3964]

👍

[@ravitsharma5492]

Thanks. I have the same problem in my Chevy Malibu 2017. What is the reason for getting throttle body dirty? I know its carbon coming from engine but this is an common for all vehicles. How does my vehicle throttle body is getting dirty again and again?

[@ScannerDanner]

All vehicles! Primarily from the PCV system

[@jordanboulay3780]

what do you mean by accessory loads? ac on? pressing throttle?

[@ScannerDanner]

Alternator loads, transmission in gear, power steering loads, AC compressor. Anything that would cause an rpm drop

[@tnamen1307]

Sir i badly need your suggestions to keep my i20 battery health in good shape... Curiosity... Say about 350 CCA is lost when vehicle is cranking. So, my question is... For how much long time should the car be running to recover back almost the lost 350 CCA? Will 350 be recovered by just keeping it idle for 10 minutes? Or do I need to drive at some speeds at some particular gears? Your suggestions based on your experiences ks highly appreciated. Thanks.

[@ScannerDanner]

I don't understand your concerns. Are you having starting issues? If your not, just drive the car, that's what the charging system is for.

[@tnamen1307]

@@ScannerDanner sir, there's no issues at all. Just curious to know. Okay let me tell this way... Before starting, battery voltage is 11V. How much long time do I need to drive or stay idle so that the battery is fully charged to 12.6 after engine off? Does it require any speeds of particular gears to run the car so that battery is fully charged?

[@tnamen1307]

@@ScannerDanner and another is... what's the general acceptable parasitic draw of a car? Is 0.035 or 35 mA a normal parasitic draw?

[@ScannerDanner]

@@tnamen1307 if your starting voltage is 11, you probably need to replace your battery, unless you have a charging system issue or a parasitic drain.

[@ScannerDanner]

@@tnamen1307 no more than 50ma with typical being under 30ma

[@GraditelMacedonia]

4:25 Ok, do you made relearning process on that throttle body after cleaning? If you do, you must mention that.

[@ScannerDanner]

keep watching, I mention about the relearning process in this video. Thanks!

[@GraditelMacedonia]

@@ScannerDanner Ooooooo yes, I'm watching all the time, till end, and i see that you mentioned after some time. Nice, and professional manner, im reacting because i think that's was a good time for explaining that relearning process. Thanks anyway.

[@peacepoet1947]

Could you disconnect the fuse to the fuel pump and turn on the key as you depress gas pedal to open the valve plate? I'm by myself and can't test it myself. Need a second person. I'm not stalling but have a rough idle. Went to a smog shop and the mechanic is telling me that I have bent valves and need an engine rebuild. Had problems with new spark plug wires and new spark plugs. He set up the timing after I had not tightened down solidly to be able to readjust the distributor timing. It doesn't need to be perfect to run at 4° BTC. Slightly retarded will cause loss of power and poorer gas mileage. The mechanic didn't think that my vehicle was worth keeping. I like my 94 GMC Sierra C3500 box truck from U-Haul. She had failed smog on the engine and EVAP system. I personally put in a new fuel pump assembly unit which fixed the EVAP system fail. I thought that the new distributor I put in myself would fix the AC Delco plugs and wires I replaced before going to hopefully pass the California smog test challenge.

[@ScannerDanner]

First, your fuel pump does not run with just the key on and you injectors will not fire either, so even if the pump was running, you will not flood the engine by opening the throttle. So all of that is unnecessary. Second, a dirty throttle body will not cause a rough idle. A very low idle speed, yes. A rough idle with a normal idle speed, absolutely not. Third, if you want your throttle body to open and you are working by yourself. Block the wheels so it cannot roll, put your parking brake on. Turn the key on, engine off, then put the truck in gear, then place a brick on your gas pedal to hold it open (engine is not running of course). On an ETC system, this should allow the throttle to open all the way. Super important that you are following exactly what I am saying as there are some real dangers here of the truck rolling on you.

[@peacepoet1947]

@@ScannerDanner thank you for responding. I've used spray cleaner inside but the coke plate is always closed. Do those cleaners work well that you add to the gas tank?

[@ScannerDanner]

@@peacepoet1947 not for cleaning the throttle body as the cleaner is only in the fuel system and the throttle body is air and PCV gases only

[@colestowing8695]

considering this was maybe 5yrs ago, you can barely tell (other than some grey hairs in the beard). Forget the car stuff...we need the anti-aging secrets!!! 😂

[@colestowing8695]

Oh! Btw...be careful of the Danelo Cavalcante situation! He was running around down here (near Longwood gardens) yesterday but apparently he's working his way north towards you guys. Keep your head on a swivel! Keep your doors locked etc, he might be getting desperate

[@ScannerDanner]

I'm definitely fatter lol Thanks man

[@mathew5956]

So dirty thottle body basically causing a restriction of airflow through 20% max plate movement compensation limit

[@ScannerDanner]

Yes sir!

[@mathew5956]

@@ScannerDanner makes sense

[@mathew5956]

@ScannerDanner thank-you sir. Im a Mechanic training to be an autosparky and find your videos very helpful

[@JamesSmith-xs7sr]

Watched a ex co worker hold the throttle wide open with a hood prop, & quickly cleaned the throttle body with the engine running "WFO"! Idiot... All because it wouldnt open koeo, lol. He almost got the cleaning rag sucked into the engine as well.

[@ScannerDanner]

🫨 damn that's crazy

[@youutartur1104]

That's cool and all but I think you should start a fitness channel now. Yolked as a mf.