5.7 Indmar engine with fuel injection will very infrequently not start (once during 4 hours of wakeboarding). After running fine, turn off engine (5 minutes max) to switch riders and when I try to start up it turns over well, idles briefly then stalls, after few attempts it will turn over but not start. Tried putting and neutral then gunning it but again stalls. Wait a few minutes then it starts right up and runs fine. I replaced the fuel filter which was surprisingly dirty and added Heat in case there was water in the fuel. Ran fine a few weeks, then did it again Friday (last time on boat). I just replace the fuel filter again just to see how bad it was it seemed very clean.

It acts like vapor lock but the fuel filter and fuel line does not feel hot when I check it

Any suggestions?
Thanks
Tom