The Official Vortec 454 Info thread

[someotherguy]

With the stalling / won't go over 35, I'd start with fuel pressure test. Very likely low, due to bad pump and/or clogged filter.

Richard

 

[Bachert24]

wonder if my OBD2 buletooth scanner has a PID for fuel pressure. what readings should I be expecting?

 

[someotherguy]

wonder if my OBD2 buletooth scanner has a PID for fuel pressure. what readings should I be expecting?

You test it mechanically, with a gauge. There's a test port at the front of the intake. About 58-62 psi, anything above mid 50's should be sufficient.

Richard

 

[Bachert24]

I think I actually still have my gauge from my brand prix I will check this first when I get it home saturday, thanks!

 

[BeXtreme]

I think I actually still have my gauge from my brand prix I will check this first when I get it home saturday, thanks!

It's just a shraeder valve. I've "checked" one in a pinch with a $0.99 tire pressure gauge and then just tossed the gauge afterwards. The FPR is well known to fail as well and then you end up with fuel pressure out of spec and possibly fuel getting sucked into the manifold from the vacuum reference line. With the reference line on the back of the manifold hooked up I think you should have lower fuel pressure ~52PSI at idle and then with it disconnected(and capped on the FPR side) it should go up to ~58PSI.

 

[Bachert24]

thanks for the info! I have a gauge like the attached.Is there anything better as far as FPR without insane modifications? As far as fuel pump I seen a few recommendations for the Warlbro. I put one of these in my grand prix and it was fairly easy. Is there a how to on the forum for either of these if I search?

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[Schurkey]

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Gauges similar to that one are available from multiple sources. Generally, they include ~5 feet of thin, clear vinyl tubing connected to the nipple on the push-button pressure relief valve. The original purpose is to relieve pressure in the gauge plumbing before removing the hose from the Schrader valve. A secondary purpose is to put the free end of that clear tubing in a drain pan, and push the relief valve while the engine is running, to add extra fuel demand to the system. If the fuel pump/regulator can maintain pressure even with the relief valve open, the fuel volume produced by the pump is probably good.

The thin, clear vinyl tubing is not gasoline resistant, it gets yellowish and stiff after it's been exposed to gasoline.

Many parts stores have fuel pressure testers like that one as part of their "Loaner-Tool" program...so you wouldn't have to buy one.

There is no fuel pressure sensor, so fuel pressure information is not directly available with a scan tool. OTOH, if the fuel trims are showing significant rich-command under heavy throttle, low fuel pressure can be inferred. If the fuel trims are showing lots of rich-command at idle, it's possible that the fuel pump is weak, but more likely to be a vacuum leak especially if the IAC is near-closed.

 

[rockR67]

That's a cool truck, I think it's going to come together nicely. I did notice the CV boots on front are cracked, so you could add that to any list you've got going. Sorry if someone already mentioned those. Keep us posted on how this goes!

 

[Bachert24]

Good catch I’ll add that

 

[Bachert24]

Thanks for the info I’ll check the trims. Here’s my gauge I sent the wrong pic