I have a 05' centurion wit a 5.7 black scorpion. toward the end of last season it would occasionally not want to start right away. this year it was fine the first few times out but then started its hard start problem. then the other night it just cranked and cranked but didn't even sputter. I took the distributor cap of and it had some corrosion so I cleaned it off and it fired right up. later that day it took a few tries to get it to fire again. yesterday I put a new cap and rotor on and again it fired right up. after a few more starts through the day it started to do the same thing. I turn the key half way wait until I hear the fuel pump stop then turn it the rest of the way. the motor just cranks and cranks and never sounds like its starting to fire. i'll crank for a few seconds stop and repeat. some times it will take 5 or 6 times.
I did replace the plugs 3 years or about 275 hours ago. I also change the water separator every year. I was thinking of changing the in-line fuel filter but it really sound like a spark issue and not fuel.
any thoughts or suggestions? thank in advance.