I've got a 94 4runner v6, and i've put a lot of time working on the car. This weekend is was taking my family to go camping so we loaded up the car and started heading uphill. There came a point when the car just lost power, felt like it dropped a gear and dropped to about 55 mph. If i tried getting my speed up the rpm's would just shoot up to about 4000. I pulled over but didn't know what the problem was. I tried to keep going but still had the same problem. On the way back the car seemed to work fine on a downhill or flat road, but once we headed uphill the problem started again. any ideas what my problem is?