Another 454 Vortec Build Thread - Documenting, Q&A, Help

[Bachert24]

Well, that verifies you have a fuel pressure issue.. but doesn't narrow down why. You could have a bad check valve in the pump, leaking injectors, or a bad regulator. If you block off the return line and the fuel pressure builds above 60 PSI and doesn't bleed down anymore, you will have narrowed it down to the FPR.

If you block the return line and pressure still doesn't build and still bleeds down, then you need to check power and ground wires at the pump to make sure they are solid. If they are, then you have a bad pump.

If the pump build up above 60, but still bleeds down, you should check fuel volume by seeing how fast it fills a container of a known size. If volume is good, then you will need to pull the manifold and fuel rail out with the injectors still connected and see if you can see the injectors actually leak. If they aren't leaking, then it is a bad pump.

How important is the fuel pressure sensor? I just looked and nothing plugged into it and no wires in the harness. Could this be the issue?

 

[Supercharged111]

How important is the fuel pressure sensor? I just looked and nothing plugged into it and no wires in the harness. Could this be the issue?

As previously stated there is no fuel pressure sensor.

 

[Bachert24]

As previously stated there is no fuel pressure sensor.

There’s 2 plugs on top of the fuel pump what are they? One closest to the rear has no plug no connector and no wires. The other one does. I’m looking for schematics in the posted manuals and I can’t find it.

 

[Supercharged111]

There’s 2 plugs on top of the fuel pump what are they? One closest to the rear has no plug no connector and no wires. The other one does. I’m looking for schematics in the posted manuals and I can’t find it.

One is for the pump the other is for a fuel tank pressure sensor. It's a MAP sensor basically, part of the evap system. As far as I know 2500/3500 trucks never used that sensor.

 

[Scottm]

Bex, how long should the stock rail and regulator hold pressure? My Holley aftermarket fpr bleeds down pretty fast, but I don't think it hurts anything, as it goes immediately to full pressure when I hit the key.

 

[Scottm]

Super, I think they started using a fuel pressure sensor starting in 98. It was an option for me to wire in with the 0411 swap.

 

[Bachert24]

One is for the pump the other is for a fuel tank pressure sensor. It's a MAP sensor basically, part of the evap system. As far as I know 2500/3500 trucks never used that sensor.

That tells me this is the wrong pump or like stated below this is a new sensor for the year. Would this even cause my drivability issues? Anyone know where to find the Pinouts?

 

[Supercharged111]

Super, I think they started using a fuel pressure sensor starting in 98. It was an option for me to wire in with the 0411 swap.

It's NOT a fuel pressure sensor!

That tells me this is the wrong pump or like stated below this is a new sensor for the year. Would this even cause my drivability issues? Anyone know where to find the Pinouts?

No, the presence of or lack of this sensor will not cause any drivability issues.

 

[Bachert24]

It's NOT a fuel pressure sensor!



No, the presence of or lack of this sensor will not cause any drivability issues.

Thank you sir you truly are Awesome

 

[Scottm]

"Yeah, I'm going to have to go ahead and disagree with ya there..."

1998 c/k factory service manual: