Will not accelerate?

2002 CHEVROLET TRAILBLAZER
159,000 MILES • 4.2L • V6 • 4WD • AUTOMATIC
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RIC MCKITRICK
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  • 5 POSTS
Changed fuel pump, converter, camshaft actuator and sensor TPS throttle body and accelerator nothing has changed.
Nov 1, 2023 at 9:09 PM
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STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
We need to run the codes to see if any are stored, it sounds like the car is in limp mode, and this will help us see which system is having a problem. Please go over these guides to help us see how to fix the problem:

https://www.2carpros.com/articles/reduced-power-limp-mode

and

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

Please go over these guides and get back to us.


Nov 2, 2023 at 2:20 AM
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RIC MCKITRICK
  • MEMBER
  • 5 POSTS
P0300 is the 2 codes it brings up and I also changed the crank sensor and the knock sensor beside it and still nothing changed
Nov 3, 2023 at 3:58 AM
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STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
It sounds like you have a clogged exhaust system or the MAF sensor is bad, here is a guide to help you check the exhaust for blockage:

https://www.2carpros.com/articles/how-to-test-a-catalytic-converter

Here is the location of the MAP sensor so you can swap it out. Also is the engine misfiring when accelerating? Please check the air filter as well. Check out the images (below). Please let us know what happens.
Nov 5, 2023 at 2:27 AM
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RIC MCKITRICK
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  • 5 POSTS
Replaced all they above MAF, MAP, and new cat converter and exhaust system. also, I have tried it completely unhooked and still the same.
Nov 5, 2023 at 2:47 AM
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STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Can you upload a video of the engine running so I can hear it? Also, can you double check the fuel pressure? here are two guides to help, you can rent a fuel pressure gauge from the auto parts store for cheap or free.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

and

https://www.2carpros.com/articles/engine-has-low-power-output

Fuel Pressure .................... 48-54 psi
KOEO Key On Engine Off

Please let us know what happens.




Nov 6, 2023 at 12:05 AM
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RIC MCKITRICK
  • MEMBER
  • 5 POSTS
Fuel pressure is 60 lbs running and with key on.
Nov 6, 2023 at 1:15 AM
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STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Did you check the air filter? Also, when the engine is idling do you hear a rattling sound from the front of the engine? Can you upload a video of the engine idling and then rev it once so I can see, I think you may have a timing chain that has jumped. Check out the images (below). Please let us know what happens.
Nov 7, 2023 at 12:27 AM
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RIC MCKITRICK
  • MEMBER
  • 5 POSTS
The problem was a broke coil!! It shut down 3 cylinders, but the vehicle never missed a lick just would not rev up (accelerate). thank you very much for your help.
Nov 11, 2023 at 9:27 PM
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STRAILER
  • Experienced Mechanic
  • 55,238 POSTS
Glad you could get it fixed, thanks for letting us know. Please use 2CarPros anytime we are here to help.
Nov 13, 2023 at 1:00 AM
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