Chevrolet Repair: chevy repair, crankshaft sensor, fuel regulator

Question
1995 cavalier 2.2l having a problem with the fuel system. car sometimes idles rough. was out the other day and would not start. finally got it started and made it home but would not idle. the next day it started fine but cranked a while before it started. changed fuel filter, no difference.  When it wouldn't start I sprayed starer fluid in the intake to be sure it was a fuel problem and it started for just a second.
I'm thinking fuel pump or fuel regulator.Thanks for the help.

Answer
hmm check the fuses, and then check for engine codes, is the chek engine light coming on? could be the crankshaft sensor or the fuel pressure switch or fuel pump but there are ways to test each of those, all too long to put here, go get a manual at your auto parts store, it will have pictures and step-by-step instructions on how to diagnose this. sorry i couldn't be or more help.