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mike switzer
mike switzer,
Category: Honda
Satisfied Customers: 449
Experience:  lead diagnostic tech at Aamco
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I have 2007 Honda Accord VP, 2.4L, auto trans, VIN

Customer Question

Hi,
I have 2007 Honda Accord VP, 2.4L, auto trans, VIN 1HGCM56107A152459
There are NO CODE, everything seems normal .
The symptoms I have are:
At cold start, Engine hold 1500RPM a bit longer than other car, like 5-7 minutes before slowly drops down to 1000RPM, If I give it a light push on gas pedal, it would hold around 1200RPM for awhile before back down to 1000RPM again. Even when engine are running for hour, if I turn off and restart, it would take 30 second to get RPM down.
When I shift to R, engine RPM would go up 1200 briefly by itself, when I shift to N, engine RPM would go up 1200 briefly again, when I shift to D, engine RPM would go up 1200 briefly again .
When I reduce speed to around 15- 25 MPH, I would need to apply brakes harder because RPM surges up 1500RPM then down as the transmission down gear. At complete stop, RPM would not drop down quick enough and have tendency to goes up by itself. Let say while decelerate to a stop, I shift to N, RPM would go up to 2000RPM for at least 10-15 seconds.
Thanks for your time
Son
Submitted: 8 months ago.
Category: Honda
Expert:  Pete replied 8 months ago.

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

If your engine coolant temp sensor is stuck on reading that the engine is cold (usually 0 degrees or colder) it can cause the idle to do this here and not set any codes as the engine computer thinks it is this cold out.

I would have this signal checked to see if this sensor needs replaced.It can be checked on an engine data list view on a compatible scan tool plugged into your vehicle.

If this is o.k. there is a intake air bypass control thermal valve that can fail.This is in top of the engine as shown here.

https://www.dropbox.com/s/etckr3l7ptxtlo1/image-03-22.gif?dl=0

Make sure all connections are clean and tight to this valve and if these are o.k. this valve most likely needs replaced.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Customer: replied 8 months ago.
Pete,I can not open the link you gave me (https://www.dropbox.com/s/etck…)Son
Expert:  Pete replied 8 months ago.

How about now

https://www.dropbox.com/s/etckr3l7ptxtlo1/image-03-22.gif?dl=0

Let me know if you need anything else and feel free to rate my help here.

Thanks Pete

Customer: replied 8 months ago.
Pete,
I tried the link on three browsers, none of them open. By the way, do you have pictures of coolant temperature sensor and intake air bypass control thermal valve and how to test them ? My scanner only read code not detail enough for checking bad component.
Customer: replied 8 months ago.
Hi Pete,I block the hose from intake air bypass control thermal valve to test and it does not change anything. Temp gauge shows normal reading and fan come on and off regularly.Anything else you want me to check for ?
Expert:  Pete replied 8 months ago.

That is odd as I havent had any issues before uploading the pictures.Is there any way you can try on another computer/lap top or smart phone and see if it opens then at all?

If you have blocked air flow and no change and the engine cooling fan operates properly most likely these components are o.k.

When you checked for vacuum leaks did you inject smoke into the intake to locate any hard to see leaks like intake gaskets leaking as this can be common in some cases and cause this here needing replaced?Let me know.

Customer: replied 8 months ago.
Pete,
I did open picture with another PC;Everything I did to check are:
Clean Throttle even it looks good. I don't have smoke stuff so I spray clean stuff everywhere and water after that. Verify action of gas pedal and throttle plate at key on position #2. intake air bypass control thermal valve open when cold and it closes when hot. I even unplug one by one MAP, MAF, Pedal position sensor, TPS while engine runs to see engine reacts to sensors (clear the codes after that). I was able to see signals on each pin of Gas pedal sensor and TPS but I dont have circuit diagram to understand these signal are correct or not.Let say with engine is running and I let car goes 15 MPH down hill with Neutral, RPM would goes up to 1600-1800 RPM, would it be normal like that ? I think the clue for my problems are: The RPM goes down slowly to idle is one problem and anytime car's speed change or shifting gear, RPM would go up is another concern.Thanks
Expert:  Pete replied 8 months ago.

The idle shouldnt reach this high in neutral down hill.It should stay at idle speed.

My info shows two different throttle controls and I want to make sure I am looking at the correct one.Does your model have the electronic accelerator pedal and electronic throttle actuator control?

Customer: replied 8 months ago.
Pete,Yes,The TPS is Honda Part No.: 16400-RAA-A21
Throttle Body, Electronic Control (Gmc4A)And
Part No. 37971-RCA-A01
Part Description Sensor Assy., Accelerator PedalSon
Expert:  Pete replied 8 months ago.

Since your scan tool is unable to read data and with all of this that has been checked here already you can try and disconnect the accelerator pedal and see if the idle drops to normal.If it does then the throttle pedal assembly needs replaced.If it continues to act up then I would suspect the throttle actuator needs replaced.Most common for this issue is the throttle body/throttle actuator needing replaced to correct this here with what has been checked and performed already.

Thanks Pete

Customer: replied 8 months ago.
Pete,Unplug Accelerator pedal sensor will cause hunting RPM, it goes up and down 1000 -2000 RPM.Unplug TPS will cause smaller swing but the weird thing was I put the car in D and I could drive the car up to 40 MPH with gas pedal. RPM was high around 3000 and it seems transmission was stuck at 3rd gear.Anytime I unplug something, there is always a code and situation changed but did not make idle RPM normal.Even I don't have good scan tool, what data you want me to check ? Please tell me where ( what port/pin) and how the signal should be.Right now I am at work, so please tell me the whole thing step by step that you think I should do, for examble: check this if good then do this, if not do this etc. I will re-check everything. Would you consult with your team regarding this issue ?Thanks
Son
Expert:  Pete replied 8 months ago.

I dont show a manual test procedure for these myself.It looks like you will need a scan tool that can read the engine data signals to view data for some of the testing info.If you would like I can open your question for others here to see if anyone else can assist further just let me know.

Thanks Pete

Customer: replied 8 months ago.
Pete,Yes please ask others for meThanksSon
Expert:  Pete replied 8 months ago.

I will open your question up for others here to see if someone else can assist further on this as there may be others here that may have more info on what to check or do with this issue.I hope you can get this resolved with ease.No need to reply to my last post here unless it is a last resort as it will keep your question locked to me and others will not be able to view it.If you feel you want to continue to work with me on this feel free to reply at any time but keep in mind in some cases it can be difficult to fully diagnose or help repair this without seeing your vehicle.

Thanks Pete

Customer: replied 8 months ago.
Pete,One more question, You did mention about using scanner ..., let assume that I could borrow, please tell me what to look for .Thanks
Son
Expert:  Pete replied 8 months ago.

You would look at the engine or throttle data lists and see if the throttle position sensor actual and desired match and if they do not then the throttle actuator is usually at fault here as well as check the accelerator pedal sensor signal to see if desired and actual match and if they do not then the accelerator pedal needs replaced.

Thanks Pete

Customer: replied 8 months ago.
Pete,Have you forward my issues to other technicians yet ? Nobody contacts me !Someone mentions about perform ECM relearn idle; Do I need to , then how ?ThanksSon
Expert:  Pete replied 8 months ago.

I have oped out.I will re opt out again here to see if anyone can help further.

Expert:  justinsbg replied 8 months ago.
Hi,
My name is ***** ***** I would be happy to help. I have had some experience with this issue. Give me a few to look up some information. Thanks!
Expert:  justinsbg replied 8 months ago.

Reminder, I have not been paid at this point and won't be until I receive a positive rating from you. At that point I will receive a portion of what you've already paid just answer.

I work solely on Honda/Acura vehicles and I have seen this issue several times. I have found that updating the ECM (car computer) with the most current software will correct this issue on the vehicles I have seen. This will have to be done either at the dealership as most independent shops don't have the capabilities to do it. It will usually run around $100.00. Just take it to the dealership and tell them you would like to have your computer updated and they will perform the procedure for you. This is something that I would do first before doing any other diagnostics on the vehicle. Car computers have become so advanced and need to be updated every now and then to work out any kinks that may come up. It's not much different than updating your home computer or laptop on a regular basis. Honda is constantly coming up with software updates to fix issues like this. Have the computer updated and this will more than likely take care of this.

You can go ahead and rate me positively. Don't worry, there aren't additional charges for posting to this thread after you rate so we can keep chatting. Thanks!

Customer: replied 8 months ago.
Thank you for your input, I'll do that and feed back later.Son
Expert:  justinsbg replied 8 months ago.

Okay. Please don't forget to rate as this is how I get compensated from your deposit. Thanks and I will look for your response.

Customer: replied 8 months ago.
Rating for Pete and Justinsbg,I contact justanswer.com in the high hope to solve my car’s problem and it is worth to try because you said 100% satisfaction guaranteed.#1 Your answers did not make sense most of the time.
#2 I finally found a defective part by replacing one by one from a friend car.Therefore, I can not give you two a positive rating.
Expert:  mike switzer replied 8 months ago.

are you still needing help?