All right, I know more about cars than most people, but I can't figure out my cars problem. About 7 months ago, I replaced the fuel pump because of obvious reasons. Now, 7 months later, it feels like its broken again. For example, here are the symptoms: When I start the car, it starts fine, but idles rough, and when I turn the air on, it almost dies, and when at a stoplight with the air on, I have to give it a little gas to keep the idle up, and then when I accelerate to get on the highway, the car struggles a little to get up to high speeds, and I can tell by the way the car is hesitating during acceleration and by observing the RPM needle, which is jerky on the way up. I'm thinking it could be a fuel filter, spark plug wires, cap & roter...This is weird, could it be the alternator??? I put a used one in last year from a 93 volvo. Please let me know what you all may think. Thanks.

 

Things to check:
Fuel filter
Throttle body and idle motor(try cleaning it)
O2 sensor
Mass Flow sensor
Tune up

 

Something else you can add to your list of suspects, is any air entering downstream from the AMM. Check all of the intake manifold vacuum lines for deterioration ,and the intake air snorkel tube for pinholes and cracks. The intake manifold gasket is a common source of air leaks, and fairly easy to replace.
If you suspect low fuel volume or pressure, because of a bad/weak fuel pump/s, clogged filter or bad fuel pressure regulator, check or have someone else check the fuel volume and pressure at the fuel rail to rule that possibility out. The pressure can be checked with a gauge at the valve on the fuel rail, but volume is a little more involved.