1978 Ford F-150 Accelerator Pedal Locked

Tiny
DANAROTHROCK
  • MEMBER
  • 1978 FORD F-150
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 85,000 MILES
Weird problem. Drives normally until the engine heats up. Then the accelerator pedal gets locked and vehicle won't run past 30mph. If the ignition switch is then turned off, the gas pedal is immediately unlocked. Turn the key back on, the pedal is locked.

What causes this? How can I fix?
Saturday, February 21st, 2009 AT 12:49 PM

8 Replies

Tiny
BILLYMAC
  • MECHANIC
  • 2,204 POSTS
Disconnect cruise control if you have one.
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Saturday, February 21st, 2009 AT 1:43 PM
Tiny
DANAROTHROCK
  • MEMBER
  • 9 POSTS
No cruise control.

Please try again.

Checked it again tonight. Same thing.

Will the gas pedal lock if transmission fluid is low?
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Saturday, February 21st, 2009 AT 10:23 PM
Tiny
BILLYMAC
  • MECHANIC
  • 2,204 POSTS
Hi have a cpl questions
#! What type fuel system carb fuel inj?
#2 is the year in your post right?
#3do you have a high idle sensor on this trk?
#4 do you have a 2 barrell carb?
#5what engine do you have
please try and answer these will be up all nite billymac
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Saturday, February 21st, 2009 AT 10:53 PM
Tiny
DANAROTHROCK
  • MEMBER
  • 9 POSTS
It's a two-barrel carburetor.
Yup, 1978 Ford F150 van 6-cyl 80,000 miles.
300 cu. In. Straight 6-cyl
I doubt if it has a high-idle sensor. Where would that be? What does it look like?
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Saturday, February 21st, 2009 AT 11:17 PM
Tiny
BILLYMAC
  • MECHANIC
  • 2,204 POSTS
Hi. Well you see I can, t see the relation between the manual carb and the elec system. As in why the key cycleing on and off would free the accell. Try this unplug all elec plugs going to the carb. See if still locks. If not plug one plug at a time back in. When you get to the plug that causes the prob. Let me know. This is a very strange prob and I am interested in finding out the actual prob. So let me know thanks billymac
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Saturday, February 21st, 2009 AT 11:24 PM
Tiny
DANAROTHROCK
  • MEMBER
  • 9 POSTS
I wish it was that easy. There is no electrical connection to the carburetor. I replaced that carb over a year ago and remember it well. Went through 3 carbs before I found one that held gas.

What about the tranny? Haven't replaced it yet. Could it have an electrical switch of some type?
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Saturday, February 21st, 2009 AT 11:42 PM
Tiny
BILLYMAC
  • MECHANIC
  • 2,204 POSTS
No trans has no elec that would cause this let me do some research and I will get back tommorrow. Strange lol gotta be something billymac
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Saturday, February 21st, 2009 AT 11:46 PM
Tiny
BLIZZARDELF
  • MEMBER
  • 8 POSTS
When the engine is under a load, it will tilt enough to allow something to get in the way of the accelerator rod going to the carb.
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Sunday, April 26th, 2009 AT 11:36 AM

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