stick-shift.

I was driving a hill today, and while in 4th gear my RPM's sped up. It felt like I was slowing down and the RPMs went up unmatched the speed at which I was going (I maintained the speed I was going).

It shouldn't be the clutch (it's new).

It almost seemed like I was going in and out of OD, but my OD wasn't no (and it didn't show the signs of a ruined OD later on. I checked by turning on and off the OD and the RPM change was normal).

Could it be a fuel injection screw up?

It sounds like a slipping clutch, you should check it for correct adjustment. There should be some slack in the cable, make sure it is not too tight.
Dan

That was kind of my gut feeling, but I wasn't sure. It might even help explain my "skip" thing from late last year (which I didn't fix...I didn't drive my car for a month and today was the first day back at driving it).

When I got my car the clutch slipped at cruise speed and I thought I would need a clutch right away. I checked the adjustment, loosened it some and it still slipped a little.

I just drove it and after awhile I realized it was not slipping anymore, it has been about 6 years. I suspected the car may not have been driven much just before I got it and guessed that may have been the reason it slipped.

Dan

With the help of a friend, I replaced the clutch cable today. And by "I" I mean actually "my friend". Anyways, the old one was gunked up and couldn't be adjusted. With the new one in, the car shifts so much nicer now, and seems to have (so far) solved the issues.

Still not sure what caused that weird oil/gas issue, but it hasn't been evident lately. Once I changed the oil, it seemed to stop. No idea why.