01 Xj Fuel Pump Check Valve Question

[CMK4425]

I dropped the tank and removed the fuel pump. Both strainers are filthy and the inside of the tank is also dirty. Anyway I was messing around with the lovely all-in-one fuel filter/regulator/check valve and I noticed that if I squirt degreaser in the output that it freely flows out of the input. Am I wrong but shouldn't the check valve if working properly stop anything from flowing this way?

[birchlakeXJ]

Not completely familiar with the design of the fuel pump assembly, but I would suggest that as long as you have it out, that you replace the entire assembly. (with anything but an Airtex; Bosch is a good brand of fuel pump)

A 10 year old fuel pump has given you pretty good service, and I imagine that you pulled the assembly because of a symptom? If so, please describe..........

[CMK4425]

I have been messing around with a misfire issue. I put a fuel pressure gauge on it and my pressure was low and not holding once the engine was killed. I have already replaced the coil pack, spark plugs (before checking fuel pressure), I also pulled the fuel rail to make sure none of my injectors were leaking. Also while I had them out I cleaned them. It wouldn't be that big of a deal but our inspection checks for codes and will fail you for a misfire code, regardless if the MIL is on or not. I really miss my '77 Bronco sometimes.

[birchlakeXJ]

If your pressure was out of spec (49 psi plus or minus 5 psi for your 01), then don't hesitate. REPLACE that pump assembly.

If you have low pressure, the problem isn't the check valve. It is in the pump/regulator part of the assembly.

[CMK4425]

I was going to change both strainers and the filter/regulator on top and then see if my pressure is correct before I change the pump itself. I am correct in thinking that clogged filters can drop the pressure also? I would rather put a bosch pump back in it and changing it out separate is alot cheaper. The whole bosch module is $310 vs. $200 changing out each part

[birchlakeXJ]

Fine, but replacing the entire assembly lowers the possibility that you have to drop the tank again.

Regardless, you need to get to 49 psi at idle. Good luck!