The "already tried" portion of your question was not displayed when I answered your question. The 11.8 v woukd be low, did you jump start the vehicle? I have seen the act of jump starting cause the throttle control to fail. So, to answer your question, no, I do not think a low battery could have influanced this, but the jump starting or charging may have.
The only downside to the capacitance discharge, would be that you do not get a "pass" of "fail" after adaptation takes place.
As to the lifeless sound when turning over, a common cause for a no start or intermittent no start would be a failed fuel pump. Typically when the fuel pumps fail it is after sitting for some time, usually cold. Typically the car may fire and run or sputter for a few seconds then die and not start at all (does this sound familiar?).
If the vehicle won't start have someone else crank over the starter while you go back to the area of the right rear door, listen underneath the car for a "buzzing" of the fuel pump. If you hear the pump and it is still not starting the fuel pump is likely not the cause. If however you do not hear the "buzzing", bang on the bottom of the fuel tank with your hand or if you have a big rubber or plastic hammer that works better. Often this will giggle the electrical brush contacts of the fuel pump enough to allow the motor to start, as should the engine at this time.
If this does not work, and it still won't buzz and start, there are other possible causes for the fuel pump not to get it's supply voltage. At least now you know that the fuel pump is not running and narrows down the possibilities.
If it is buzzing and won't start you need to check for spark. If you do not know how, contact me and we will go that route should it be necessary.
The fuel pump is the most likely cause for this year model. I suggest you try this if it does not correct the condition let me know and I will continue to assist you.
Another possibility for no start would be flooding due to carbon on the valves. The 1998 - 2001 2.8L 30 valve motors (ATQ, AHA) are prone to "flooding" when cold. This condition is typically brought on after a short drive cycle on a cold engine. A classic example would be starting the vehicle cold, pulling it out of the garage, and shutting it off, attempting to start the next morning. When attempting to start cold in the a.m. the engine will be difficult to start, and run poorly if at all. This is usually caused by carbon particles (byproduct of combustion) getting stuck on the valve seats and not allowing them to seal. The reduction in compression does not provide sufficient pressure and the combustion event can not occur so fuel is unburned and the cylinders become "flooded" with unburned fuel. Could this have been the condition when you last ran the engine?
Please explain how this all came about from the last time it was running untill it would not start.
I hope I have answered your questions and addressed your concerns, should you have any further questions regarding this matter, please do not hesitate to ask. I want you to be 100% satisfied with my answer.
Positive feedback, referrals and bonuses are always appreciated! If you decide to accept this answer, please click the ACCEPT button by this answer.