Hello all - I'm a newb on the forums but think I can handle most repairs. I've read numerous posts on S40s not starting, including the classic FPG issues. Please hear me out and review my situation if you could?

The back story - We just acquired a used 2000 S40 for my son. The previous owner was upfront about occasional starting issues that sounded like the FPG issue, but he said it was coil packs. Eventually he changed both coils, plugs and wires and claimed the problem was solved, so we agreed to purchase at that point. (he also claimed to change out the FPG) We have only owned this car 1 week, but when its running its running real nice with plenty of pep.

My immediate experience - After taking ownership we did have a longer than normal starting time on a couple occasions, but after a couple days, we began to notice coolant consumption and eventual high temp gauge. I would top off the resevior to max, run the car and it would be cool with normal temp, but then after a couple days this would happen again. After the third time topping it off, it appeared to level off and stop consuming so I wrote it off to it being low from the beginning. I will be doing a thermostat but am waiting for the OE exact to come in at NAPA (tmrw). My neighbor pulled a code calling out cylinder 2 misfire and cleared it - I don't know the code or what the current readings are.

My current situation - with the car running at normal temp I did a compression test, all 4 cylinders were 140-145. That appeared good so I got to thinking that maybe coolant was leaking through the turbo. We actually did see small infrequent puffs of white smoke out a small exhaust leak in the braided pipe before the cat. I started the car fine, buttoned it up and went in for the night. This morning we come out and the car will just crank and not turn over.

As of tonight, these are the things I've looked at for troubleshooting:

Coolant level - good
Compression - good 140-145
Spark - good all 4 plugs/coils sparking strong
Plugs - noticed they were fuel wet (they were perfect brownish grey when I took them out for the compression test yesterday)
Oil - fresh change and it looked like perfect used oil - no signs of coolant.
Fuel filter - just installed new. (old one appeared clean anyway)
Fuel pressure - don't know yet, I will grab the Harbor Freight gauge soon, but fuel pump appears to energize.
FPG - previous owner says he changed it, I can't prove that but I do not see any fuel droplets coming out of curved tube - can it fail other ways?
Coil packs and wires - new changed by previous owner.
MAF - I bought cleaner but didn't clean it yet.
Air - airbox/filter appears unrestricted and clean
Exhaust - we feel pressure out tail pipe when cranking but can't prove catalytic converter is not restricted.
Coolant temp sensor - I will test its resistance when I do the thermostat.
Other sensors - nothing to report as I just don't know the proper order to test and also don't want to throw $$ away just yet.

Really frustrated - If I have fuel, compression, air, and spark; what other sensor could be causing this? Could a bad FPG cause more than lengthy start and actually cause no start?

Looking forward to some ideas. Thanks a bunch, Steve. (sorry for long post but I wanted to give all the details)