4 problems with 1999 S80 2.9
 

1) if the car hasnt been driven for over 6hrs, it starts right up otherwise it takes 2 to 3 tries to start.

2) whats an inexpensive way to erase the airbag code?

3) fuel gauge is inaccurate. it does not meet the right end on a full tank.

3) i get throttle fluxuations at 2000rpms

Please help resolve these issues.
Thank all.

I think your main problem here is maybe a Fuel Filter...when the car is at rest for an extended time the fuel at the filter will relax a little letting fuel through..but after you drive it a little while it gets fuel pressure built up and starts to restrict the flow eventually cutting off the supply of fuel.

When you really excellerate it can cut off the fuel even faster..like you say around 2000 or more rpm's.

Tech would know more then me..but thats my humble opinion. Good Luck and Happy Motoring....

I changed the fuel filter recently. I feel this is an electrical issue. I can accelerate hard and not lose power at all.