Help Please! starting problem

[Pureluck868]

Alright so I realize that probably no one will be able to diagnose the problem just from my description, but I will try to provide as many details as possible so maybe someone can give me a clue as to whats going on here. Any help would be greatly appreciated. And yes I know theres a million other forums about BRZs with problems starting, but so far I have not found a single one matching my exact problem.
I have a 2013 BRZ 33k miles with a vortech supercharger and flexfuel tune(oil and super charger fluid changed religously every 4k miles. Anyways my car is a keyless push start and has always started up instantly, never even a sputter. So I left it sitting for 3 weeks outside with an outdoor car cover while I was in college. I realized I couldnt live without my baby so I went home to get it and bring it to college. First time starting it up, it turned over for maybe 3 seconds without starting(had 93 octane in tank) so I turned it off and tried again and it started up, this was very odd as it had always started up instantaneously. It has been a month since then and 9/10 times it will take a couple tries to start. Odd thing is, it seems to start easier when cold. When engine is hot just after driving, it definitely seems like it is harder to start, sometimes it takes me even 4-5 tries. I am currently running e85(e73 to be exact), BUT when this problem started I was running 93, so it is NOT because of the E85. It is also NOT the battery, as I have checked the voltage and it looks good. The starter does not sound strained at all either, so I do not think it is that. I hooked the car up to obd auto doctor and it showed no codes(no CEL on dash either), some sensors may have been removed because the car is heavily modified and stripped down, but I did not see any problems through an obd2 scan, but I can post a picture of all the sensor stats when running if anyone thinks that would help. Once started, the idle RPMs are steady and do not jump around, just as always. I have tried priming it by pushing start button without clutch in and letting it sit for a couple minutes, and then starting it up, doesnt seem to make a noticeable difference. I think this is everything. Again any theories would be greatly appreciated, im 18 and dont have the money to take this thing to the shop.

[soundman98]

post a video of it cranking.

and you need to load-check the battery, not voltage check it. just about any battery will test 'good' as a voltage test. applying a load to the battery can have drastically different results.