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AMEDEE
AMEDEE, FORD TECHNICIAN
Category: Ford
Satisfied Customers: 26615
Experience:  ASE CERTIFIED TECHNICIAN ADVANCED LEVEL SPECIALIST. Wisconsin certified emissions state inspector
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My 2002 Thunderbird misfires at 2900 RPM while in Park or

Customer Question

my 2002 Thunderbird misfires at 2900 RPM while in Park or Neutral. It is also slightly rough running but will accelerate normally while driving. My mechanic says this is an RPM limiting feature of the car. I've had the car for a few years and never noticed this before.
JA: How old is the transmission? Have you checked the fuel filters?
Customer: Everything is stock so 15+ years only 60K miles. Am having the 60K service done now I think fuel filters are part of that.
JA: Are you fixing your Thunderbird yourself? What have you tried so far?
Customer: No
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 4 months ago.
Category: Ford
Expert:  AMEDEE replied 4 months ago.

Hello and welcome!

My name is ***** ***** I can assist you with your question.

Expert:  AMEDEE replied 4 months ago.

I am very sorry your having this issue with your vehicle.

I will try my best to answer all of your questions.

However, before we get started, please let me mention a few things.

1. If at any point you would like to speak on the phone, please feel free to request a phone call on your end and I can call you right away.

2. If you dont understand any technical terms or anything that I mention (component tests or theory or operation), please let me know and I will provide you with a more in debt explanation or answer.

3. Please understand that I am here to help you any way I can.

Customer: replied 4 months ago.
OK thanks
Expert:  AMEDEE replied 4 months ago.

If the engine idles that high in park or neutral, that is not normal.

The most common cause for this condition is a faulty throttle position sensor or air/vacuum leak.

Some other possible causes are a stuck throttle body, throttle plate, and a sticking throttle cable.

I would start by checking for air/vacuum leaks first and fixing or replacing any as needed and then checking the TPS and throttle body (sticking or stuck open for any reason).

Customer: replied 4 months ago.
No I just want to read what you think about my problem
Expert:  AMEDEE replied 4 months ago.

Do you see my reply above?

Customer: replied 4 months ago.
I did not ask a clear enough question. When just idling my car runs about 800 rpm, very normal. It is when reving the engine that I discovered this rough running. As I said before. The car runs a little rough at speed. There appears to be a small misfire or back fire when running.
Customer: replied 4 months ago.
I see your reply.
Expert:  AMEDEE replied 4 months ago.

Thank you for that information.

Expert:  AMEDEE replied 4 months ago.

So this problem does or does not happen in drive while accelerating?

Customer: replied 4 months ago.
No except for what I feel as a slight misfire
Expert:  AMEDEE replied 4 months ago.

So it does not happen in drive right?

It is only in park or neutral?

Customer: replied 4 months ago.
Expert:  AMEDEE replied 4 months ago.

And there is no codes in the computer and no check engine light illuminated?

Customer: replied 4 months ago.
not at this time there was for a day or two but it turned off and has not returned.
Expert:  AMEDEE replied 4 months ago.

Do you know what code was stored in the computer?

Customer: replied 4 months ago.
no
Expert:  AMEDEE replied 4 months ago.

Ok, thank you for that information.

I would get that checked as your next step. If there is a lean or rich code, fuel trim code or converter code or even mass air flow sensor code, it might be contributing to this issue.

However, if not, then yes, I agree with the mechanic as this sounds like a rev limiter preventing the engine from accelerating too high.

Customer: replied 4 months ago.
thanks
Expert:  AMEDEE replied 4 months ago.

Your welcome!

I am glad I can help!

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