99 454 Burb power loss problem (fuel starvation?)

[crashandburn]

My Burb has had the hard start problem (injectors and/or fuel pressure regulator) since I bought it. A couple weeks ago I let my brother in law borrow it for the weekend and he had to cross a flooded road, deep enough that the tailpipe was submerged. Since then I started noticing a loss in power at higher rpm, intermittent, but it felt like a clogged filter.

So I finally did the Bosch injector upgrade and a new FPR. New filter while I was there. Starts like a dream now. But the power loss came back, only worse. Figured maybe my brother in law got some crap in the tank, so I put another filter in.

No change.

Maybe I have A LOT of crap on the tank? Maybe it's the pump?
It sure does feel like fuel starvation, but it is intermittent. What kind of pressure am I looking for, running, no load, load, key on engine off?

Also if I check the actual pump pressure, like on the fuel line before the filter, what should it be there?

Thanks!

 

[crashandburn]

Drove around with a gauge just now, and I have about 45 psi off the gas, and 52 on the gas, which falls off to 48 or so at redline. Seems a bit low. Strange thing is, those are the numbers when it is running good, and when it is falling on its face.

 

[crashandburn]

Thought more about it. If the problem was fuel delivery, the pressure would surely drop while the symptom was showing. What would make it starve? On a hunch, I disconnected the MAF sensor, forcing it into closed loop. It started, stumbled, surged stumbled some more, and then it figured itself out. Ran beautiful. I guess the MAF wasn't reading the air coming in, so it didn't spray in the right amount of fuel.
Changed the MAF, problem gone.
Thanks for all the answers though.

 

[Phil513]

lol, if I had a clue, I would have helped.

But I'm sure glad you got it fixed.