jon-d

My fuel pressure while running is 50 psi and after turning it off it took 3 minutes to drop down to 30 psi and then a total 5 minutes to drop down to about 26 psi. Does this look right to you all?

Reason I'm asking is I have almost 190,000 on my '96 Grand and wonder if the fuel pump should be changed out. I have no idea if any previous owners had ever changed out that pump.

dave1123

It's about normal for the mileage and the pump checkvalve shows some wear, but the pressure is good and unless it takes a long time cranking in the morning to fire up, I wouldn't worry about it. The one in my 2000 WJ has 260K miles on it and has the same pressures as yours. My pressure in the morning is zero, but turn the key on and it's 50.

jon-d

Thanks Dave, that's reassuring. This is my off road toy and sometimes I am in a remote location and because of that I am allways looking things over and performing PMs.

Chrismorton10

Not sure if its the same on the older models but my 02 WJ has the flowback check valve actually inside the fuel filter. I'm also not sure if it has a second one at the pump or not but maybe change your filter if it's a concern to you. I know sometimes the little things like that bother me until they're fixed. Hope this helps!

dave1123

Yes. On the WJ, the filter contains the pressure control valve and a reverse flow check valve, both of which can be replaced just by changing the filter. This is the reason they cost more than just a simple filter.

I've been told (rumored) that an in-tank pump without pressure controls will develop 100 psi or the maximum limits of it's physical construction before it stops pumping. That stands to reason because if anything above that is needed, a pump designed for hydraulic systems must be used. Due to the light design of our fuel pumps, I can see where it would burn out or fail if the output was totally blocked. SO, there is a large volume of fuel bypassing the pressure control and returning to tank and that can wear out the limiting valves.

If you have pressure problems, replace the pressure control before condemning the pump.