bad engine? Code P0300 random multiple misfire?

2002 CHEVROLET ASTRO
256,000 MILES • 4.3L • V6 • 2WD • AUTOMATIC
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THESOUNDGUY
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New cap, rotor, wires, plugs, cam sensor, crank sensor, mass air flow, octane booster, sea foam, air filter and still a bad miss. Code P0300 random multiple misfires. Thanks in advance for your help.
Aug 12, 2022 at 5:32 PM
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STRAILER
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We should start with a compression test, or you can send me a video of the engine cranking over so I can tell if the engine is in good shape or not.

This guide can help:

https://www.2carpros.com/articles/how-to-test-engine-compression

If the compression is good and the engine has fresh spark plugs etc., I would do a fuel filter because they can clog up limiting the amount of fuel getting to the engine.

Here is a video of the job being done and instructions in the images below for your car:

https://youtu.be/cMa2bp4jbNU

Clear the codes after the job is done. Check out the diagrams (below). Please let us know what happens.
Aug 13, 2022 at 9:40 AM
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THESOUNDGUY
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So sorry sir, but I put a new fuel filter on it too, I just failed to put it in the list.
Aug 13, 2022 at 9:46 AM
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STRAILER
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It sounds like the fuel pump is starting to go out. To be sure this guide can help you check the fuel pressure. I have also included how to change the pump out just in case in the images below.

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

Key On Engine Off .................... 55-62 psi

Check out the diagrams (below). Please let us know what happens.
Aug 15, 2022 at 11:09 AM
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THESOUNDGUY
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I have 55-62. My mechanic suggested a distributor. I have one coming. 268,000 miles.
Aug 15, 2022 at 4:49 PM
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STRAILER
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Yep, a worn distributor can help, let me know what happens.
Aug 16, 2022 at 6:52 PM