1995 Toyota Corolla -- While driving it suddenly loos power

1995 Toyota Corolla, 175000 miles, one day my car won’t start, so I tow the car to near Firestone location. They change ignition coil and rotor. Also same time they changed valve cover gasket and they did fuel system tune up. After that I was getting jerks during gear shifting, so they said I need to change distributor, distributor cap, spark plug and wire and all of the above cost was $1400. I told them to put all my original part back and I did install brand new distributor, rotor, coil wire and plug by my self.

Problem is when I am driving car, it suddenly loose power and shift gear to first. If I stop and start again, it will run normal. It does not do all the time but more often so I can't ignore it. Also on highway some times I get two or three jerks and run again normal.

Could you please tell me what could be the problem?

Thanks for providing really good service.