Failing fuel pump?

I did a search and didnt really see what I need. I recently picked up a 87 4.0 auto. This is my 4th XJ, one 93 one 95 and one 85 with a 2.8. I think this is the only renix one then which Im not familiar with?
Couple questions. It cranks longer than the others to start, 5 seconds maybe then runs fine. The fuel pump is fairly noisy (buzzing)in comparison all the time it seems, but almost seems every once and a while its quiet. It seems low on power compared to the other reg 4.0., running 235 and have to floor it in 3rd to do 65 up a 4% grade? Mileage seems normal, tail pipe is clean metal it seems instead of some black deposits (to lean?) no codes or CEL, havent smogged it in a while. Are these symptoms of a dying fuel pump?
BTW the CAT and fuel fltr,plugs etc are fairly new. Just adjusted the TPS, was .05 @ closed and set to .083 as reccomended, but seems to max out @ 4.54 volts if I recall.
Thanks for any help or links.

My 91 XJ 4.0 takes about 3 secs to start up and the fuel pump hums like crazy.. The P.O. says it did this for the last 3 yrs he owned it and has done it the past 3 months I have owned it. Runs fine and gets 19-20 mpg.. Need to replace it before it leaves me stranded somewhere though.. just for the extra insurance.

I experienced the whining fuel pump in my original '88XJ Limited twice in its 354,000 miles and I presently have it on a sometimes basis in my present '88XJ Limited with 220,000 miles. On the original XJ, it got pretty loud and persistent before I replaced it. I was told (probably here on the forum) that it was likely the worst that would happen was that it would cut out and I might have to sit for 20 - 30 minutes and then could continue on - - - so, one likely would not become stranded and could limp it home. I've never heard the whining fuel pump in my wife's '91XJ (also 4.0L) with 262,000 miles. Don

Interested to read what the TSB for "noisy fuel pump" along with a slew of other little nagging things (ratteling rear door,TPS about 3 times,bad grounds, etc for my 87 at least is, but im to cheap to pay for an alldata subscription.