No power when i go to pass

1996 GMC C1500
250,000 MILES • 5.7L • V8 • AUTOMATIC
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DANIEL STOPKA
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Idle engine seems to run fine, even driving seems okay at time engine stutters or drops out when trying to pass no power engine stumbles. Catalytic temperatures right is 341° front and 486° rr. Left is 397° front 515 rr. I cannot find anyone that has a vacuum gauge to test the engine is breathing.
Feb 18, 2017 at 10:56 AM
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HMAC300
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check fuel pressure with a gauge auto parts rent it pressure should be 60-66 psi with key on. See link.
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator
Feb 18, 2017 at 11:04 AM
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STRAILER
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Hey DANIEL,

There can be many things that can cause this like a plugged fuel filter, but I am thinking it could be the mass air flow sensor that needs to be cleaned, also check the air filter and here are a few guide that can help you.

https://www.2carpros.com/articles/mass-air-flow-service

and

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

Please run some tests and get back to us so we can continue helping you.

Best, Ken
Feb 20, 2017 at 9:53 AM
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DANIEL STOPKA
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Hey Ken sorry it has taken so long for me to get back with but time and money has slowed me down.. So i cleanded the mass air flow sensor and replaced air cleaner i also replaced the fue filter that had rusty lines and took a lottle more work. Truck runs much better but still have a shutter in the engine at high R's i know it's in the engine because i can rev up the engine and feel it so i dont believe it's trans. I looked at harmonic balancer and it looks fine everything is flush on the front of it. I dont know if it could be engine mounts. But it runs alot better so far.also going to give it a full tune up plugs wire cap and rotor ect...just a heads up there is not service engine warning light or codes except for 02 sensor bank 2 senser 2
Mar 30, 2017 at 10:42 AM
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STRAILER
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The full tune up should help it could be the spark plugs are misfiring at higher RPM's

Please let us know what happens.

Best, Ken
Mar 31, 2017 at 12:22 PM