as Jason said do you no for sure its fuel issue.... you need to find out..... pull a spark plug wire off a spark plug and stick a screw driver in the rubber boot... then touch it to metal while a buddy turns the key to let the engine turn over... if you see sparks then you have fire to the plugs so then your back at a fuel problem lol.
at which point uve replaced all those parts id try fuel pump relay..... after u have narrowed down for sure its fuel problem then come back and ask question again and explain u already made sure it was fuel related...
you could test that your getting power to the fuel pump also.
make sure ur in a quiet quiet area and no radio... no talking... turn the key on without trying to start the engine and listen... you should hear the fuel pump turn on for a second as it primes the lines up with fuel.
it would be a lot easier to help if you did tell the vehicle info also but we helped best we could. give it a try.
Now you ready yet to diagnose the problem or are you going to keep guessing and wasting money? Got spark? Do you have injector pulse? If those are not there you probably have a bad crankshaft sensor. Chrysler's have an ASD relay that fails often. Other vehicles have their own common problems. You don't have a chance in hell to figure it out...especially when you don't tell us WTF kind of vehicle it is!!
do you know for sure its a fuel issue? it would help to know what kind of car it is. it could be a million different things if we don't have that info
check your fuses
Ive put fuel pump fyel filter and fuel pump regulator on and it still wont start
