Vortec 5.7 fuel trims positive, running rich, fuel pressure issue?

Discussion in 'Engine Performance + Maintenance' started by mistaake, Jul 5, 2018.

  1. pro17

    pro17 I'm Awesome

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    If OP is for sure there are no vacuum leaks, he could test each injector by doing an injector balance test, but I dont know if that's possible with CPI (maybe it is, but that the entire upper plenum has to be taken off - I haven't had a vortec in front of me in like 14 years). If its possible to get to each injector, he might need a scan tool to do it. There may even been an android app for doing the test.

    If he doesn't have a scan tool, and the injectors can be accessed one by one, a balance tester could be hooked to each one to pulse them and record the drop. But if I remember, that cant be done on the spider without taking the intake off?
     
  2. mistaake

    mistaake Real Name: Michael

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    I don't have a capable scantool for that unfortunately. I did watch that video actually, I subscribe to that channel :)
     
  3. mistaake

    mistaake Real Name: Michael

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    Basically what I'm getting to understand is that assuming there is nothing wrong with the fuel spider (in terms of injectors and fuel pressure regulator) that I installed brand new not too long ago I need to replace the fuel pump. So I'm going to research where exactly I cut in from the top and replace my fuel pump with some generic $30 lifetime warranty piece of junk from the parts store and report back. When it inevitably fails because it's not ACDelco, I can put a new one in easy enough due to my access hole.
     
  4. pro17

    pro17 I'm Awesome

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    Dont cut the bed. Do like I did and unzip all 6-8 bolts underneath, and slide the bed back. Itll take you and a friend to lift it up a few inches, then back about a foot or so, and let it sit on the frame. There will be enough room for you to get in behind the cab and replace it. Replace the filter also. In fact it may even be clogged right now.
     
  5. mistaake

    mistaake Real Name: Michael

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    Hey, I appreciate the input, but it's a Suburban... and I replaced the fuel filter last week.
     

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