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my friends son has a 02 ford escape with the 3.0 v6 . he told me he had problems with fuel pressure leaking down and found the pressure regulator was bad so he changed it and now his pressure is running between 90 and 100 psi . my question , is that pressure to high and is the pressure regulator on the pump a one way flow and is it possible he put the regulator in backwards to get pressure so high ??? he told me their was no arrow or in and out marked on the regulator showing the flow direction .
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I’d think if there was room for the regulator to be installed the wrong way, the next step is to simply reinstall the regulator in the opposite direction. Of all places to aimlessly search on the internet, I did find a spec on Rock Auto for fuel pressure. I don’t know if you can take it for truth, but it’s more believable than 100 PSI.
I moved onto repair link to try and find what the pressure regulator actually looked like and got the dealer pic below. According to repair link, the 9F775 is the pulsation damper and the 9H321 is what they’re calling a pressure relief valve. I’ll take that for a pressure regulator.
I was able to get the Motorcraft part number out of it and did a part number search over at rock auto and it gave me this:
Looking at that and assuming I’ve found the right part, those thread pitches look to be different from side to side. He shouldn’t have been able to install the part wrong. Am I in the right ball park?
*Post edited. I originally posted that I didn’t think it was a return system. However, I found another diagram with the fuel lines and it looks a lot more like a return fuel system now. I’d go after that regulator as backwards or faulty.
Sounds like the work he did was actually inside the fuel tank. Is that correct? If you are speaking of the pressure being developed by the pump with the engine off then 90 to 100 PSI is not unusual. It would be useful to measure the pressure with the engine running and the pressure should be about 65 PSI and increase slightly if you floor it. You can also just pull the vacuum line off the fuel pressure regulator on the fuel rail (on the engine) and the fuel pressure should increase to max which might be 90 psi.
yes the regulator inside the tank on the pump is what he changed . he sent me video of the fuel pressure and the reading was running between 90 and 100 psi with the motor running . motor off and it slowly and I mean slowly dropped in about 3 hrs. to about 50 psi and stayed there . again my question is that pressure way to high and is that regulator backwards ???
OK. The fuel pressure regulator for the purpose of regulating the fuel pressure to the injectors is on the fuel rail on top of the engine. What I suspect he changed is the one-way valve which will keep fuel pressure from quickly bleeding off thus causing hard starting. If the fuel trim numbers are good the pressure is OK. You would get a check engine light if the fuel mixture was out of speck.
If he’s checking pressure at the rail fitting using a proper (working) gauge, at idle he should see 65 or so.. 90 would cause me to go searching for vacuum leaks. And there are several ways to do that
Nice photos.. 9H321 is the fuel rail pressure regulator, 9H323 is the pressure sensor, and the bottom picture looks to be a replacement fuel pressure testing port.
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