hard starting '95 Sport follow-up

It's not the LPP been there done that!!!
I also don't believe it's vapor lock as my '95's problem got continually worse. I was lucky enough to find an original style pump (Carter 962) and installed it and haven't had a problem since.
I would believe that if it was vapor caused by the new ethanol fuel as some want to believe it would vapor lock with the new pump also but it hasn't yet.
I disected my old pump and the only thing that I saw that could be a possible cause (besides the pump being over 20 years old) is there is a rubber flapper in the bottom that allows fuel to travel "OUT" the angled port to the braided line to the tank return line, but that doesn't account for the hot no start only.
The only thing I can think of is the pump gets hot when sitting under the box next to the hot engine, overheats and then for some reason fails to pump which causes the LPP to force the fuel out the rubber flapper to the return.
The air in the line I believe could be caused by the rail being under pressure at shutdown then when a start is attempted the injectors open using the fuel in the rail with no fuel to replace it. The question is where does the air come from as its a closed system???
Possibly when the LPP is pumping the fuel out the bottom of the HPP it scavange's the fuel out of the HPP creating an air pocket when the injectors open???
These are some of the questions and possibilities I've been kicking around unfortunately I have been to busy with other things to dedicate time into testing theories and the little time I get on the water I want to spend skiing not testing.
So if someone with time wants to do some testing I have some ideas and another similar pump (with out the second bottom port) that they could try, I used the pump last year for a short time and it seemed to solve the problem but I did not have enough testing on it where I would say "go get this pump and it will solve the problem"

I have a hunch you're replacement LPP is not a good one. I used to bleed my LPP at the Shrader valve or hit the ignition key four or five times to get it to hot start when it intermittently would act up.   Replacing the LPP again with a "good one" might be the answer.

Might be worth adding the fuel cell conversion that Gary S has been working on. I seem to recall that's why they added the Fuel Cell in 1996.

I started a topic which got pretty long earlier this summer and I wanted to follow up with what I feel has solved the problem of hard starting, when warm, of my '95 Sport N without a Fuel Cell but with multi-port injection. Search 1xsculler if you want to read about the specifics of my problem and the many replies of people trying to help. It's evidently a common problem.
I connected a fuel pressure gauge to the Schrader valve on the fuel rail. This fuel pressure gauge has a purge button right at the base of the gauge with a clear piece of plastic tubing attached to it which is about three feet long.
My warm starting problem has not occurred all summer until yesterday. It doesn't matter whether the gauge reads less than ten psi with one key turn or 40 psi with three or four key turns, it starts right up with no issues. BUT, in the past when it decided not to start it absolutely wouldn't. It would crank, fire, cough and die a hundred times or as long as I tried to start it.. Yesterday when it decided not to start for the first time this summer I turned the key off and on several times to get the pressure up and it wouldn't go up so I pressed the purge valve on the fuel pressure gauge which caused gasoline to run out of the plastic tubing which I dangled over the side of the boat. I turned the key on and off several times and purged each time and finally I could the pressure up to 40 psi and the engine started right up. I feel we now have a boat that we can have confidence in and I will leave the pressure gauge connected, maybe forever, as being able to purge the line seems to be the solution to a problem which was extremely frustrating to say the least.
I hope this follow-up will help others with a similar problem.