Fuel pump

[quote="scouties"]my car is a 2000 sunfire, 2.2L, my fuel pump seems to be working but it is as though it over heats and shuts down until it cools off. What could be a possible cause to this problem? All codes and test came back normal. Any answers might help solve this problem. My car will be driving normal and all scans and checks will come back normal but when I am on the highway the car will drop in speed like your foot is off the gas peddle. When I push on the peddle it wont accelerate. When the speed drop to 20km and the brake is pressed the car wil die out and it will take a few moments before it will start (by stepping on the gas a little) it doesn't always have this problem just some days. And my mechanic hooked up gauges to read the fuel pressure and everything was normal. There doesn't seem to be anything mechanically or electronically wrong with the car. Please. Any suggestions might help. Also my mechanic did a tune up were the plugs and wires were changed as well as fuel filter and air filter and the injectors and the throttle body was cleaned. The problem was there before the tune up and after. I also had a new catalic converter put on the car. If all test show the fuel pump is working fine what could it be? Help.