1989 Camry DLX. LACK OF POWER IN LOW RPMs

I just bought a 88 toyota camry dlx. The car drives fine once it's up to about 15 mph, but starting from a stop or any time it's in the low end RPMs it has a big lack of power. The fuel filter is new, I havn't had the chance to check the spark plugs, but the firing order is corect as well. There is a lot of sputter and a little bit of back fire when you hit the gas, but like I said, once its going it's fine. It's just when you're accelerating that it has trouble. My only other thoughts would be the timing or the fuel/air mixture. I removed the air filter from the intake and the car stalled as if were getting to much air and not enough fuel. That's why I changed the fuel filter. It helped, but it still does lack the power it should have.

Assuming that it is the timing or the fuel/air mixture how would I make the adjustments? I'm not sure if the distributor cap can be turned like other cars to adjust the timing or not, and I would have no clue how to change the amount of air going into it.

88 toyota camry dlx
v6
208,000 miles
There is no smoke, knocks, ticks or any other noises indicating that the motor is bad. Just the lack of power in low end.

Please help.

Thanx.

Try checking fuel pressure regulator, located on fuel rail. It has a single small vacuum line connected to the manifold. Just a hunch.