Fuel pump or not?

I tried to pass a truck the other day and when i put the pedal to the floor the xj fell on its face. Completely cut out. I let out of it and it picked right back up. So after i got around the truck i tried it again. Same thing. Then i cut everything off, radio and defrost. Tried it again, didnt cut off but it started surging. This only happens when it kicks down into the passing gear. No other time. Bought a fuel pressure gauge and checked pressure. The first reading was right on 48 psi. Cut jeep off and bleed the line. Started it back up and the needle moved from around 43-52 psi erratically. Repeated this process and same results. In the last month i have put a new cps, tps and full tune up. Just monday had a whole new exhaust ran. Also i put old tps back on today and no change. Only seems to do it after it is driven for about 2-3 minutes. Any ideas?

What RPM's are you talking about when is kicks out. Are you talking about the rev limiter. When RPMs hit to high it will cut the engine out. This is normal.

what year is ur xj? Maybe your bypass relay for the fuel pump ballast resistor is going bad. I think this relay is supposed to let your fuel pump get the max voltage to ur pump under these circumstances. During normal driving, power goes through the ballast resistor to quiet the pump down. Just an idea that came to my mind first, not sure if this could cause your problems. I'd have to consult my fsm to be sure.

It is a 98. It will only do it when kicked into passing gear. If going up a hill and it downshifts doesnt do it. Is this just the regular fuel pump relay in the box under the hood?

One more part of the test would be to watch the gauge when driving. Find a place to run the hose through the firewall. I have put a small cut in the rubber boot that lets the wiring go through the firewall.

ok, put a new pump relay in it this morning and the problem seemed to go away. Drove around for about 20 mins. Gas hand got down to about qtr tank so i filled it up. Problem came back. What is causing this. Never had to take a vehicle to the shop but looks like its going to be a first time. Would the fuel pump cause this? Thanks

I was having similar issues in my 96 a while back, and it turned out to be the fuel pump.

Took it to the shop yesterday and had it put on the scan tool. All sensors are working properly. Shop owner told me to replace the fuel pump, he has seen them with the same problems before and it turned out to be the fuel pump.

I had that problem and it turned out that the rubber fuel hose going from the pump to the line out of the tank, was too big or worn or something dumb. I replaced the small piece of hose and I haven't had a problem with the fuel system since.

I've been having very similar problems with my '96. The problems are very intermittent, and have been going on for a few weeks now. What did you find? Did you get a fix for this? My local garage suspects the fuel pump as well, but I didn't think a fuel pump could fail progressively.

Geoff