2000 V70 Xc Non-starting

[JPMCT]

I have a 2000 V70 XC, 216K, always maintained very well. Wont start, cranks until the battery dies, wont turn over. Heres the back story:

I put the car away for the summer and drove my T5M, then it came time for this to come back out, it ran rough from sitting. It developed a slower start at that time too, but it always started on the first try. Had the battery checked at that point, I was told it was fine. It started to get progressively worse, and sounded like a bad starter but still starting on first or second try, so I swapped the starter and at the same time cleaned the ETM. Seemed to fix the issue for a few days, then it returned. Kept driving it for a few weeks like this until it started to not start until a few times of cranking and sometimes a jump.

So I started to read through the forums, read up on what seemed to be the issue with the fuel pump check valve going. I waited until the morning after it had been sitting overnight, checked for fuel pressure at the fuel rail, and nothing. Then I got into the car, switched the ignition a few times to the "on" position to allow the fuel pump to get some pressure in the line. Tried the fuel pressure at the fuel rail again, and got a good splurt of gas to come out. I ordered one online, came a couple days later, and I spliced it into the line.

The next morning, cranking but wouldn't turn over again. I decided maybe it wasn't the gas at all, maybe it was either the coolant temp sensor or the MAF sensor. Tried to start it with the coolant temp sensor, wouldn't start and the fan kicked on full time, so i plugged that back in. Then I tried it with the MAF sensor unplugged, still wouldn't start, so I plugged it back in. I changed the plugs on it before taking it off the road for the summer with Volvo plugs, so that cant be it. Figuring maybe the plugs are not being given enough power to give a good spark, I threw in a set of used coil packs I had laying around, and it started! Not sure if it was really the coil packs that did the trick, or if the time it took me to throw in those coil packs I had it jumped to the battery was it. Didn't matter to me though, it started.

Ran good, started every time I went to start it but seemed like it was still a slow start, that lasted about two days. Parked it last night, came out this afternoon to go to work, and it wouldn't start again.

I think my next step is to replace the battery and look into replacing the positive terminal cable, and if that doesn't work, consider replacing the fuel injectors and/or fuel rail. Any ideas if the battery, cable, or injectors sounds like they might be bad or am I going in the wrong direction? Any input would be greatly appreciated. I should mention, no check engine lights, but pulling a code p1238-a code that was present before I put the car in storage, so that cant be the issue and shouldn't prevent it from starting.