Hard to crank and rough idle all at once

My car was running perfect, until I pulled onto a spot of high grass. I was in the grass for a few moments. I think I cut the car off. When I cranked the car, it ran rough, lunging. Took it to mechanic; replaced fuel pressure filter, mass air flow meter sensor. The mechanic is not sure what is wrong. The car will start, but sometimes he has to disconnect the two new parts before it will crank. When it does start, it runs rough, and he has to connect the gas pressure filter and the mass air flow sensor for it to remain running. It will run briefly and then cut off. Like I said, it ran perfect until I pulled through the high grass.