It's time to fix that fuel gauge and trip-meter... need help!

[nam3less]

Well, ever since I bought my 91 240sx... the fuel gauge wasn't working. That was all good... since I had my trusty tripometer (or... not so trusty anymore) I decided I'd just fill up every 200-250 miles. Well, I'm heading for a LOOOOOONG road trip back home this coming week, and I definitely should fix either the fuel gauge or the trip-meter (odometer doesn't work either when the trip doesnt work) so at least I know when to fill up >.<

The Fuel Gauge:

Well, the needle is always at E. I haven't removed the cluster yet to see whats going on, but it doesn't look like the needle is broken. The car does have a swapped SR20det in it, and I was told that sometimes people don't connect a wire? A wire going to.... the fuse box? I'm confused... but I'm not really sure how this whole cluster ECU fuel pump thing would all connect to a ... fuse box? Maybe I'm missing something. So any input or suggestions on what I should be looking for? Anything I should trace from point a to point b?

The Odometer/Trip Meter:

Well, it works sometimes... then it would just stop. I really can't give a specific scenario because it seems to be different all the time. I thought I had fixed it w/ some fuses... or it worked perfectly when I disconnected and reconnected the battery. But now it's back. Some times it can go for 10 miles.. some times not even 3... then it would just get stuck. So once again, I'm not really sure what to look for here. I'm not cluster wiring savvy so any suggestions would be appreciated.

Thanks in advance