Hello. I am new to this forum as well and am having the same problem: my 454 will not start and then idle. It'll turn over fine, but it will not start. Just a brief history, I replaced the fuel pump with a Holley electric pump from the original old purolator that I had on it. I also placed a bigger carb on it from a 625 cfm Carter carb and some new Bosch spark plugs. Due to my upgrades, now the engine will not purr like it used to; it runs like crap (when I can get it started). When I can get it started, it'll have to crank over many times, but it'll just die after a few seconds. Even if it does run for a period of time, it will not allow me to press on the gas pedal because it'll die even then. Sometimes it will spit out fuel and then die. Sometimes the carb even caught on fire.

Before I had it timed at 4 degrees BTDC with the fuel pressure at 4 psi; that is when it ran and had no trouble.

So far I've checked the float levels and they are adjusted correctly, checked the firing order sequence and that is correct. All of this trouble makes me want to take all of the new upgrades on it and put the old stuff back on.

Any thoughts?