i have an 1987 4runner with 22re & 5 speed trying to push 285-75x16's is there any way to get more power? also when i push on the gas it seems to lose speed instead of gain. can anyone help.

 Hi Patrick - well... you've added almost 4" of overall tire height from your stock tire size. The original tire size that your truck came with was a 225/75R16, and you've gone to a 285/75R16. That's a really big difference, and it's affected your gear ratio pretty substantially. 

If memory serves me correctly, your stock axle gears were a 4.10:1 ratio. With that big of a tire size difference, you really need to change your axle gears to 4.56:1 ratio, to get back all of that lost power. You see, not only does changing the size of your tire change the overall gear ratio of your drivetrain, you're also adding extra weight to the vehicle too (probably more than 100 pounds). All of it adds up quickly, even for the venerable 22RE engine (which is a phenomenal engine BTW). 

As far as your other problem goes... boy, that could be just about anything from bad gas, a clogged fuel filter, a bad O2 sensor, a clogged catalytic converter and so on. I guess my question would be is this: When you stab the gas, does the truck nose dive suddenly, then take off again (like a severe hesitation)? Or, is it simply underpowered and you're just not getting any acceleration out of it? 

Regards,

Rick

under power and has no pick up, some times u will fill a sudden small jerk and then it will slowly gain speed. i've only had the truck for about a week, just trying to find out a few things to make it run better.