fuel pump stupidity......

So on the weekend i decided to put a new fuel pump in my 97 yukon... after spendin bout 2 hours doin it, im still kinda havin problems with it...
I put in a new carter fuel pump, its workin much better than the old POS factory one that was in there,the old one would run outta gas at just under half a tank.. But its still havin problems with the sendin unit bein kinda wonkey.. :screwy: the gauge is still bouncin around alot, and take a while to come back to what the actual level is.. has anyone one else had this problem, and what else could be a problem with it ?? its drivin me freaken crazy.. hit tha gas and its full, than 5 mins later its back to half a tank.... even filling it up , it took a few mins to show that its full.. any info would be great....

Also, how badly needed is the damn skid plate thing what was on the tank mine was sooooo badly rusted it pretty much fell apart in lil peices when we un bolted it... i figured not havin it is proboly about as good as havin one on than crumbled when touchin it....

its not the sending unit its the gauge. i replaced my sending unit and then it was still doing it. then i replaced the gauge no problems now

was there a bffle unit (tray) in the tank when you replaced the fuel pump, if there is no baffle in the tank it will make the fuel guage fluctuate irraticly.