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  1. #51

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    Damn man you think I should drop it again? That's the only way I can to think to check it

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    I didn't notice any of the wires cut or damaged when I had it dropped but I didn't give it much thought. Would the o2 sensors have anything todo with pump pressure? I also rented an obd scan tool as I saw someone said I'll need it.

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    Strangely my FPR didn't have a vac hose to it..... Sound weird to you?

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    [QUOTE=edsmagichands;612446]New pump, pressure still low. as i said previously, poor/bad power or grounds in the fuel pump circuit can cause a good pump to fail to build proper pressures. you need to test the circuit before chasing possible ghosts. j cat is correct, you need to get the fuel pressure in spec in order to rule that out as a possible cause. it is not unusual for codes to not set when it seems they should.

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    forgot, test light won't do. you need to voltage drop the circuit with a digital meter(dvom). several good articles on the web with pics show you how




    looking into into this, still a bit complex for me haha.

  2. #52

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    BINGO! Problem found and fixed and the mis is gone for good. Whoever said it was the distributor assembly.... you were right my friend. Took it out replaced it and the problem cleared up instantly. Also just so its corrected the correct fuel pump pressure for the 5.7 short block is 50-55 not 60-65, had 2 mechanics come over this past weekend and schooled me in on that. Thanks for everyones input and advice lol the engine is practically new now so i shouldnt *knock knock* have any issues for a while

  3. #53
    Legend

    Join Date
    Sep 2010
    Location
    everett, massachusetts
    Posts
    1,487

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    Quote Originally Posted by Grahamwk View Post
    BINGO! Problem found and fixed and the mis is gone for good. Whoever said it was the distributor assembly.... you were right my friend. Took it out replaced it and the problem cleared up instantly. Also just so its corrected the correct fuel pump pressure for the 5.7 short block is 50-55 not 60-65, had 2 mechanics come over this past weekend and schooled me in on that. Thanks for everyones input and advice lol the engine is practically new now so i shouldnt *knock knock* have any issues for a while
    glad you have it running better . on the fuel pressure if you take the time the GM spec is 62-65 psi key on engine off. no way would 50 PSI be acceptable ..

    now rather than go on what people say , you get a gm shop manual and you will see what are the correct pressures ..

    you were also told the distributor was new ..

  4. #54

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    Here's the solution to this irritating problem, the distributor. Yeah, that simple, just swap it out or you can take it out, and clean it. Make sure you mark the distributor position before you take it out, both the rotor position and housing position, I use a ruler and make straight lines onto the firewall for reference. You only have 2 degrees to play with so be as precise as possible, or you start getting a cam code, so be as exact as possible. Also, when you take the distributor out, mark everything the way it went, so you can assemble everything the same way. Hammer the pin out of the gear and pull the shaft out, then clean the shaft. On the shaft grime will develop causing the distributor rotor to jump thus misfiring certain plugs at different rpm. Scrape it off and clean the shaft, and assemble the distributor back. If the gear has uneven teeth, might as well change it. Put it back and enjoy the ride.

  5. #55
    Jr. Apprentice
    Join Date
    Apr 2014
    Location
    jenkin Township, Pa
    Posts
    23

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    Attempting to diagnose problems without actually being able to get my hands on it is a guess...but here is an educated guess. You very well may have a poor spray pattern out of your injectors, or the may be restricted. The 2 cleaners I have had success with are Chem tool and Sea Foam. I love the Sea Foam as it does a great job cleaning this style of injector. Put in enough so you have roughly an ounce of Seafoam for every gallon of gas... do not refill it until you get below 1/4 tank as you'll dilute it. That may help.
    My best advice is to take it to a shop with full diagnostic capabilities. Beats shotgun diagnostics any day of the week!
    ​Everything in life sucks, except the things that should!

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