No start, fuel issue

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rigsboo

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I got a 97 silverado 350 5 speed z71 the fuel pump is brand new and is kicki g on and getting 60lbs of pressure at the rail while i crank it but when i stop it immediately drops to about 10 or 12lbs. Borrowed a noid light and all injectors ARE pulsing. Im currently not getting ANY codes. The vehicle is getting spark, if i pour gas or starting fluid down the throttle body it will start and run until it burns all of it out. What do you think the problem is? Im leading towards injectors or regulator but need some help on what it could be or more tests to help narrow things down.
 

east302

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Is the "security" light on?

What was your pressure with ignition on but not trying to crank?

Did it do this before the new fuel pump?

Could be a leaking injector/regulator or the pump sender not holding pressure. With the new fuel pump and the VCM correctly grounding out the injectors, I would suspect the injector assembly. If I was going to throw a part at it it would be a new injector assembly.

Here's a link to visually inspect the injectors for leaks if you want to take a look. Honestly, though, if you go through the trouble of pulling the upper intake you may as well swap in the MPFI assembly. It really improves throttle response.

http://troubleshootmyvehicle.com/gm...nZnVlbCIsInByZXNzdXJlIiwiZnVlbCBwcmVzc3VyZSJd

And here is GMs procedure for the fuel test:

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eyesi

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Apply 12 volts to red fuel pump prime wire, or a jumper in fuel pump relay slots as indicated in atached image for turn on fuel pump for testing purposes, expect 60 psi of regulated fuel pressure but, also more or less 100 psi when momentarily you pinch fuel return line (the one of smallest diameter), 100 psi is overhead pressure test, . if you get not that raise of pressure, then there are issues inside fuel tank, or in wiring harness between fuel pump relay and fuel pump. Alarm installers sometimes tap on fuel pump wiring. You can let 12 volts atached to fuel pump prime wire or fuel pump relay and make a road test.
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