Wh ii gen iii fuel sender help

[VL-VP-VT]

need some help determining which fuel sender is needed for my 2001 WH II Gen III Statesman, according to auto parts stores there were a few different ones used in these cars. the problem is that my fuel gauge is telling me I have between 1/4 tank and 1/2 tank but it is empty, when ignition is turned off it returns to the empty position, when I put fuel in it goes up a bit, I disconnected the battery today for about an hour and a half and then reconnected and the fuel gauge actually went higher. the cheapest price I can find for a sender unit is around $330 supplied only, and without knowing if this is definately the problem, I don't want to spend the $330 and it not fix the issue.
does any one know the part number for the unit I need, or even what other cars the same units were used in ?? so I can try and get one from a wrecker or ebay etc before I spend my money on a brand new unit.
every auto part store has told me that you have to buy the complete unit including fuel pump.
if anyone know's anything about these, do you know if there were any aftermarket units made and where I can get one from
is $330 about the price I should be paying for one, or is this a bit much ?
any help is greatly appreciated

[MrSirWantalot]

I found mine to be the sender unit (fuel pump module). Mine would read 3/4 full when I filled it & read empty but had 1/4 tank left. Atleast it was consistent. In all honesty I had a shit load of trouble getting the right unit mainly though fuel miser, after the third one I gave up. After I had a yarn to the mechanic we decided to give Holden a ring & suprisingly was much cheaper compaired to fuel miser & a few others, but at the same time I knew i was going genuine again. Ring Holden & give them this part number (GM-92158012) or ur VIN & see what they charge. You can also have ur dash cluster checked out too, would be cheaper & probibly ur first step. Maybe see if it can be re-calibrated? Good Luck

[VL-VP-VT]

yeah I had already had the fuel gauge recalibrated, cost me $88 to have it done. (which did not help at all)
I got a few prices on the fuel module and pumps, Holden wanted $330 for the unit, so I went to autobarn and supercheap to see if they sold aftermarket units, but they said they couldn't get them and I'd have to get a genuine one. anyway thought I'd check out the internet, well I found what I wanted on the supercheap parts guide (after the fact that they said they can't get them) any way it was a goss fuel module and pump part number GE159. and was only $147. so went back to supercheap and got them to order it. I could have ordered it over the net from noels auto supplies for the same price, but thought I'd get supercheap to do it for me, they also charged about $16 delivery, so all up it was much better than paying the $330 from holden.
I put it in the car yesterday and it seems to be fine, but I checked the resistance of the old one and the new one before putting it in and they were both giving the exact same readings, (so was a bit concerned it was not the sender) both units were giving a reading of 38 ohms at empty and around 250 ohms at full.
anyway decided to go through and put the new one in. after putting the new one in I realised that it was sitting in at a slightly different angle, so I pulled it back out and put the old one back in to see where it was sitting (works out the float was hitting up on a high part in the tank, (so the float would never reach the bottom of the tank (maybe it had spun slightly due to vibration or it had been replaced previously an not installed in the correct position.)
so anyway if anyone needs a module and pump, check out the goss catalogue. they were by far the cheapest, or noels auto supplies (internet)