My 95 acura is slow to build up r.p.ms after it is ok untel it goes to anoth er gear then does it all over again.
If you are very lucky, the installation of the timing belt was most likely done "out of time". The cam must be exactly aligned with the position of the crankshaft during the timing belt installation. The tech that installed the new timing belt should be responsible for making this adjustment, although if he/she didn't know enough to get it right the the first time you may want to have another mechanic get involved.
There's a myriad of other problems unrelated to the timing belt that could be present if the other parts of the engine were installed incorrectly. Look at the mass air flow sensor wire connection, and the entire intake system from the air filter to the throttle body, throttle position sensor, the idle air control - a small air "bypass" that allows enough air to bypass the throttle body so the engine can idle, it has wires running to it so the computer can control the idle speed. Seriously consider replacing the fuel filter if you don't know the last time it was changed, look closely at the spark plugs just to be sure none were cracked during the timing belt work.
Lastly, look at the oxygen sensors - look for the wires going to the sensors in the exhaust manifold and the exhaust pipe behind the catalytic converter. While there is little you can do to know if one or more of the oxygen sensors is bad, at least check to be sure the wires are firmly connected. Usually if the oxygen sensors are failing there will be a "Check Engine" light. Be aware the it would be a coincidence to have an Ox sensor go bad at the same time as the timing belt breaking, but it's worth checking if you are getting a CEL.
Respond with engine type, and current mileage, and we may be able to come up with more things you can try
Does the engine make any "new" noises since the timing belt failure and repair. The worst case would be if the timing belt broke while the engine was running at high speed, in many engines this can cause serious valve train damage or even damage to the pistons. If this was the case with your engine, ithe damage would almost certainly have led to a knocking, hissing, or growling noise that was not present before the timing belt broke.
A third possibility might be a problem with the spark plug wires, if they were not placed back in the correct positions after the repair, the engine would run very poorly, if at all - a six cylinder MIGHT start and run with two or more of the wires placed incorrectly, a four cylinder wouldn't start at all.