04 not building rail pressure?

[cmont58]

My buddy has an 04 that quit running the other day. Said he was driving it and it started acting like you were holding the brakes on it. Stopped and shut it off went to leave and it won't start. Truck will bump off either and run but will not start on its own. Hooked the solus up to it and it's only building about 1000 psi while cranking. If you start it on either it idles fine but as soon as you give it throttle rail pressure drops off. Put a new rail pressure sensor on it that I had laying around and pulled the line off the pressure relief valve and cranked, still does the same thing. Fass is pumping good so it's getting low pressure fuel but it seems like it's just bleeding all the pressure off. Any ideas of what could be wrong with it and what to try next?

 

[crpower]

Possibly the fca.

 

[homewrecker]

Injector tube loose, relief valve opening


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[cmont58]

We checked the relief valve and it seems to be working fine. It will build fuel pressure if you slowly increase rpm but if your gouge the throttle it drops in a hurry. I'm going to try an fca off of a different truck in the morning. It does have an II 85% over cp3 on it and didn't they modify there fca's that came with the pumps?

 

[homewrecker]

Should have a modded fca but a stock one will work fine for testing


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[natemorrell]

Ive always seen max/non regulated rail pressure when the FCA fails. This exact problem was happening on my friends 05 and it ended up being 2 loose connecting tubes. Threw some new ones in re-torqued them and all was fixed.

 

[apples24v]

Yeah I agree with natemorrell, if it was the FCA you should see maxed pressures not low. Maybe recheck/trq all the tubes first only takes a few minutes, any fuel in the oil?

 

[SixOhh]

yeah i agree with natemorrell, if it was the fca you should see maxed pressures not low. Maybe recheck/trq all the tubes first only takes a few minutes, any fuel in the oil?

what he said!