2001dodge stratus & it won't crank after changing the fuel pump and crankshaft sensor. What's the problem?

I was driving home and it started misfiring and I couldn%26#039;t accelerate. The next morning and it would crank but idle rough and skipping and then shut off. When I tried to drive it, it would go a few feet and shut off. I changed the fuel pump and then they said it wasn%26#039;t getting any fire. Then I changed the crankshaft position sensor, and it won%26#039;t crank. So do I need to replace an Engine Valve?|||Replacing parts based on guesses is a poor strategy as you are finding out. Pay for a proper diagnosis, it will be cheaper.....|||Check to see if the battery is any good and also check the alternator,try jumping it and if it starts and runs then check the alternator to make sure it is putting out at least 14 volts.|||no, you don%26#039;t need to replace anything until you run some tests. would you be happy if you went to a Doctor because you felt sick and him tell you that you need a kidney transplant without running any tests? Pull the upstream O2 sensor, and then try to start it. If it starts up you have a restricted exhaust, probably caused by a defective catalatic converter. (which could result from a miss fire) If this doesn%26#039;t work, then put a vaccum gauge on it and turn the engine over with the starter. I assume that by crank you mean start and run because nothing you say you have done would cause the engine not to turn over by the starter. if their is a valve train problem the vaccum gauge will fluctuate a lot, if the engine is a 4 cylinder, it may fluctuate a little anyway, a valve problem will cause it to fluctuate a lot.|||After listen ur complain. Please check ur crankshaft sensor, be sure that u have assembly the right way, the right configuration, the notch on ur gear have %26quot;meet%26quot; the notch at the engine block. U miss one teeth, it won%26#039;t start untill u make it right. Valve doesn%26#039;t have connection to missfiring and skipping, the worst news is only u drive rough and knocking and less power.