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Hesitation and bucking?

Tiny
DLDOMES
  • MEMBER
  • 2007 FORD F-150
  • V8
  • 4WD
  • AUTOMATIC
  • 53,189 MILES
Hi Guys,
I have been fighting this for two months now. My Mechanic and two Ford service writers do not know what to make of it.

So far I have heard of several people having similar issues but no one has posted any updates for what the fix was.

Once warm, The engine will buck or hesitate, usually when maintaining cruising speed or sitting at a light in drive. When out of gear it idles smoothly, when accelerating it is smooth and after the initial moment has a lot of power.

Once in September I had a message come up on the com that said "running at reduced power". Everything seemed normal and It quit a minute later and never happened again.

I have had the injectors cleaned, changed the fuel filter, air Filter, ran two tanks of high octane all to no avail.

Scan showed that one cylinder ran hot one time, but no other codes.

Any ideas?
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Friday, November 5th, 2010 AT 8:16 PM

15 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Hello,

It sounds like the engine is misfiring which can cause the reduced power light to come on. Can you check the codes? Here is a guide to help you see what you are in for:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

The MAF could be an issue. Try cleaning it to see if it takes care of the problem. They make a special cleaner for them. You can get it at most parts stores. Let me know if it makes a change.

https://www.2carpros.com/articles/mass-air-flow-service

Please let us know what you find.

Cheers
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
DLDOMES
  • MEMBER
  • 6 POSTS
Thanks,
We are checking the MAF now and will try it on the highway tonight.

Another mechanic that has tried to diagnose it said that it feels like a coil, but which one? Apparently the codes do not come up very quick on Fords, your thoughts?

I have not had a code come up since the one " running at reduced power" late summer.
The other thing that is funny, when running on cruise control it seems less violent.
Thanks.
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
DLDOMES
  • MEMBER
  • 6 POSTS
The MAF apparently is okay.
Next issue is the coils; a Ford service manager said check the top of the coils as often they will crack if there is a problem.
Next the plugs; they are supposed to be good for 100,000 miles but require servicing three times in that span and are a three part plug and require a special extractor to ensure you get them out. "Recommended dealer only" in case one does not come out cleanly.
Wow!
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
I could be a coil, but it should set the engine code and identify which cylinder is causing the misfire.
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
DLDOMES
  • MEMBER
  • 6 POSTS
There is no evident cracks showing on the coils. I guess the next step is to take it to Ford to have the plugs checked.

I do not like having to do that.
Any other ideas?
Thanks.
Darrell
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Darrell,
The only thing that has my attention is the number one cylinder. Has anyone checked the compression in that cylinder? You could have a burnt valve. Also, if you remove the plug from that cylinder, what does it look like? Has the crank sensor been checked? Finally, is the vehicle still under power-train warranty?
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+1
Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
DLDOMES
  • MEMBER
  • 6 POSTS
Unfortunately, no it is not. I am going to be taking it in to get that checked, and will ask to see what it looks like, compression and crank sensor. Apparently it has a three part plug that likes to seize and I do not want to chance of it fracturing.
I would like to know why specifically the number one?
I will post the results.
Thanks
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
I look forward to hearing from you.
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
DLDOMES
  • MEMBER
  • 6 POSTS
Okay they replace the MAF sensor and did a tune up and now the problem is gone. Thanks for your help 2Carpros!
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
According to your first post, "scan showed that one cylinder ran hot one time."
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
GREGOTEX5
  • MEMBER
  • 1 POST
Did you ever have any luck with the hesitation? Mine is doing the exact same thing.
I want to sell it, but need to fix this first.
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
JGKRUEGER
  • MEMBER
  • 1 POST
I just had this hesitation problem fixed on my F150. It turned out to be two broken and clogged catalytic converters. The truck was okay at idle and at low city speeds but could not push the exhaust pressure out at high throttle. $1,400.00 later, it runs just fine again.
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,643 POSTS
Great addition to this thread! Please feel free to help out whenever you are on the site. :)

Cheers, Ken
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Tuesday, April 6th, 2021 AT 12:42 PM
Tiny
HAYES39
  • MEMBER
  • 1 POST
Had the same problem, no codes, 135,000 miles, changed all eight coils, no issues so far, two months in, so far so good, fingers crossed.
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Friday, February 17th, 2023 AT 12:24 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,643 POSTS
Yep, I think the coils fixed it, thanks for sharing.
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Saturday, February 18th, 2023 AT 5:51 PM

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