Bob,

If your car has been is storage for five years and not been run, I would HIGHLY recommend that your pull the gas tank and have it cleaned out. Your local radiator shop should do the job for under $100 if you take the tank in to them.
The tank comes out pretty easy. Just be careful when removing the filler pipe and overflow pipe as I hear they are getting hard to find. This is also a great time to paint the exterior of the tank and inspect the trunk area for rust. Nothing kills a classic Volvo faster than rust.

My 1800 had also sat up for a number of years, and there was a lot of rust in the tank. No rust throughs, but after a few weeks I was going through a fuel filter ever three or four days. The gas was working the fine rust particles loose and they were plugging up the fuel lines and filter.

Good luck.....

Oliver
1966 P1800S ... Worlds of fun with style