95 MAZDA 626 Idle problem

I have a 95 626 with a idle problem.
Last week it was running great and but I had to put a water pump on the car. It is a 2.0 dual overhead cam. I had to remove the timing belt to get the pump installed.
I read the book on how to retime the engine. Installed the water pump and a new timing belt.
The engine fired right up, but now I have a idle problem. When I have the car in drive it wants to stall at traffic lights.
What did I do. Could I have got the timing one tooth off on the crank to cause this problem?

Any help?

I have a 99 Mazda 626 with the 4 cylinder that was towed to my shop for the same reason. They had broke the timing belt and had a new one installed. The timing I have checked and is dead on. The car will idle and drive fine when cold, when it heats up it wants to stall. Go to a mechanic and have a cylinder leak down test performed when the engine is hot. If you are driving it with the timing off there is a slight chance of valve damage. You may also have vavles sticking when the engine is hot.

my 97 mazda 626 seems to have a similiar problem, however i know it needs a o2 sensor, i feel like that won't solve the problem. I seem to notice that if you do come to a slower stop, and let the transmission shift down each gear instead of coming to a quick stop and it going from say 45mph to 0 in minimal time, the car wont die. It feel like the problem may be in the transmission for me. And there were no signs before this either, all of the sudden it started doing it, and somedays, there are no problems at all. Strange cars:banghead: