PO171 and po174 2000 4.2 4wd
where is vacuum to the fpr?
highest I saw was 30 psi and it would leak to 20
what is this line under the bed go to?
where do I disconnect vacuum to for?(
The FPR is on the fuel rail, not in the back. Post #14. Review the whole thread, we discussed the FPR.
If it won't go over 30, you have an issue, fuel pump may be on its last legs. I don't know where that line goes.
If it won't go over 30, you have an issue, fuel pump may be on its last legs. I don't know where that line goes.
Now do the FPR test. Pull the vacuum line and the pressure should go up at least 5 psi. If you can't get at the FPR easily, follow the vacuum line back from it and pull it at that end. Review the whole thread. Clear the codes and see if they come back.
walked outside my gauge showed 0 until I turned key on. Maybe my harbor freight gauge is leaking I’m checking. I can’t find the regulator I believe I disconnect vacuum to egr valve
i cleared codes and drove about 20 miles.
it runs about 30 psi
i believe it drops after a few hours of being off until I turn the key.
Last edited by FLFordF150; Aug 6, 2023 at 09:56 PM.
https://www.obd-codes.com/p0460
https://www.obd-codes.com/p0455
What is the fuel pressure with it running?
https://www.obd-codes.com/p0455
What is the fuel pressure with it running?
i installed new pump unit
I turn key it goes to about 30 psi
i believe a few hours later when I return it will be 0-10 psi until I turn the key on.
I haven’t confirmed the psi specs via google.
also can’t exactly see fuel pressure regulator
prior to changing unit seems I’m 10-12 mpg
why do we think I need to unplug vacuum to regulator ??
Last edited by FLFordF150; Aug 6, 2023 at 09:58 PM.
The FPR is on the fuel rail that sits on top of the injectors, pictured in post #14. You need to unplug the vacuum to see if it's operating properly. If it's leaking it's sucking gas through the vacuum line into the manifold, there will be gas in the vacuum line.
Specs are 28 to 40.
Specs are 28 to 40.
I can’t access this at the moment maybe when I remove battery and numerous other parts according to that video it’s posted. I’m at 30 psi after changing pump unit how long should it hold 30 psi before dropping? Maybe if I knew where other end of line plugs in it would be easier or doable.





