I have an old SRX that has served me well with 230k miles on it. About a month ago, the car was running fine and my wife parked it in the driveway. Next day I went out to start it and it won't start. Battery is fine, gas feed is fine (checked with a fuel pressure gauge). When cranking the engine, it sounds like it wants to start, but just won't fire. It's been a while since I last changed the plugs (over 100k miles), and I happen to have new coil packs on hand, so I replaced all the spark plugs, coil packs, and for good measure, the fuel injectors. No luck. I then figure it might be the cam shaft positioning sensors, so I changed them also. It is throwing no codes, and no old codes are recorded. I searched the forum, but couldn't find anything specific that I haven't tried already. Anyone have thoughts on how to go about diagnosing the problem?