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Old 05-25-2014, 12:32 AM   #1
terbronco7
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Jerking while at cruise speed

No matter what gear I am in the truck wont stay at a constant cruise just jerks like I am goosing the throttle. Any ideas as to what may be causing this?
As always thanks everyone for the feedback.
Not sure of exact tranny but has granny 4 speed in it.
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Old 05-25-2014, 08:29 AM   #2
63burban4x4
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Re: Jerking while at cruise speed

Oh, you mean the TRUCK is jerking........
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Old 05-25-2014, 08:34 AM   #3
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Re: Jerking while at cruise speed

Quote:
Originally Posted by terbronco7 View Post
No matter what gear I am in the truck wont stay at a constant cruise just jerks like I am goosing the throttle. Any ideas as to what may be causing this?
As always thanks everyone for the feedback.
Not sure of exact tranny but has granny 4 speed in it.
Does the engine idle okay? Does it rev smoothly when you when you hit the throttle in neutral? This is sounds like the fuel bowl might be overflowing (bad needle/seat). Revving the throttle will hide the problem but it misbehaves when you try to run steady.

By the way, your thread title should win you a POTD award. (post of the day)

Good luck...ned.
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Old 05-25-2014, 10:50 AM   #4
bosephus
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Re: Jerking while at cruise speed

Quote:
Originally Posted by 63burban4x4 View Post
Oh, you mean the TRUCK is jerking........
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Old 05-25-2014, 10:59 AM   #5
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Re: Jerking while at cruise speed

It may be too lean at low load.

What it your air fuel ratio? My 350 won't do a light cruise much leaner than 15:1. Any leaner and it jerks. Maybe you have a small vac leak or the floats are too low?
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Old 05-25-2014, 05:41 PM   #6
BR3W CITY
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Re: Jerking while at cruise speed

Didn't California pass a law against on-road jerking? ..... as well as Assisted On Road Jerking?
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Old 05-25-2014, 10:51 PM   #7
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Re: Jerking while at cruise speed

Possible water in the gas
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Old 05-26-2014, 10:38 AM   #8
Wrenchbender Ret
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Re: Jerking while at cruise speed

Some engines will run rough at part throttle because of excessive timing. Try driving with the vacuum advance disconnected. If it helps you may have to get an adjustable vacuum chamber & limit the advance.
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Old 05-26-2014, 10:49 AM   #9
Chevy Fleetside
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Re: Jerking while at cruise speed

Check the fuel filter also. or just replace it.
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