Chevrolet Repair: 1999 Cavilier, vacuum hoses, pontiac sunfire

Question
Hi Curtis, my daughter has a 1999 2.4 automatic Pontiac Sunfire convertible approximate 112,000 miles.  Just recently she said it started running rough then just quit on the side of the road.  I tried to start it several times but no good.  It just cranks and cranks and does not fire.  I had it towed then after it was removed from the truck discreditable it started and ran for about a hour at idle then it stalled out again during the test ride.. I checked the obvious such as the gas, air filter vacuum hoses etc.. Any ideas?

Thanx
Doug

Answer
Well I need to know a couple more things. First, when it won't start I need to know if it is getting fuel to the cylinders. Easiest way to check for that is to turn the engine over for 10 to 15 seconds then pull a spark plug, if it is wet and smells like gas then your getting fuel. Then I need you to check for spark, if you don't have a spark tester then the easiest way to check for that is to pull a spark plug and leave it attached to the plug wire, then have someone turn the engine over, while it's turning over, watch the plug to see if it sparks. Do those and get back to me, we will go from there.