My truck will not go over 45mph

Discussion in 'Chevy Truck Forum' started by This is MY c10 truck, Dec 18, 2017.

  1. This is MY c10 truck

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    I have a 1986 Chevy c10 4.3 v6 automatic. That will not go over 45 mph after about 20 miles of driving. The engine runs and sounds smooth when the truck shifts it is smooth it just looses power and will slow in speed. Any thoughts??
     
  2. MikeG

    MikeG Full Member

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    Bad Throttle Position Sensor.............?
     
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  3. This is MY c10 truck

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    That's what I thought too, I replaced it yesterday.
     
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  4. jkeaton

    jkeaton Full Member

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    Did this just start all the sudden out of the blue? Miles? Last tune up? Do you have catalytic converters? Check engine light on?
     
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  5. This is MY c10 truck

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    I gave the truck a tune up a week ago or so, drove it to and from work for a few days and that's when it started. I replaced the TPS thinking that was the problem, guess not. The truck has 119k miles on it. I have not had any issues with it ever. No leaks, no odd noises. When I first started driving it it shifts great but after about 20 miles or so I lose speed and power to go any faster than around 45mph. I have a I think it is called a reasanator sorry for spelling, not a cat. Converter.
     
  6. MikeG

    MikeG Full Member

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    :idea:............ a loose/ bad Vacuum Line??
     
  7. This is MY c10 truck

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    I will check that when I get it home good call.
     
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  8. This is MY c10 truck

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    Well, can not seem to find or remedy my transmission problem. Fluid level is good, no smoke smell or burnt smell, and color is about like fresh fluid. I am at a total loss as what it could be. Any more ideas, anyone???
     
  9. jkeaton

    jkeaton Full Member

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    Fuel pump, clogged fuel filter, can you check fuel pressure?
     
  10. This is MY c10 truck

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    Next on the list, thank you for the suggestion.
     
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