I have twin 502 MPI's but one will not start. The other bust right off. It is getting fire to the plugs and fuel to the rail. Any ideas will be appreciated. I'm stumped.

is it popping at all? Dist tight? dbbl check the lanyard switch. Do you have a scan tool to see what everything looks like with the sensors?

I would also check the dist cap & rotor if corroded it may not be getting enough fire to the plugs, Also I have seen that an injected engine that gets flooded can contaminate the oil by washing the cylinders. 1 more trick I learned pop the coil wire loose but not off & try it. Was told the increased gap will make a hotter spark at the plug & should give an idea where to go from there.