At first it wouldn't turn over. Now I have changed the stater and the crank sensor, it will turn over but not start. I know there is fuel running throug. What else can it be...

. Check all under hood and under dash fuses with a test light or multimeter.

. Check for codes.

. Replace the Ignition Control Module, if you have the 4.3L engine.

. Check all under hood and under dash fuses with a test light or multimeter.

. Check for codes.

. Replace the Ignition Control Module, if you have the 4.3L engine.

Alread checked fuses, I have a 5.3 liter

You need compreesion fuel and spark, it appears you may not have spark. So I would check there first. Checking for codes is usually done when you have a drivability problem not a no start problem. Good luck