87 Audi Coupe GT Fuel delivery problem, Any advice?

I have an 87 Coupe GT 2.2L. I have been having trouble with it starting. The problem started about 6 months ago while running some errands. I would drive and park at several places and i came out from like the 5th store i went to and my car wouldnt start. It started when i turned the key and then immidietly stalled out. After that, the starter would kick in and engine would turn but not spark up and start. I left the car and came back the next day to the same problem although it seemed like it wanted to start a little more. I left it another night and came back the next day, where it started after a couple minutes. I drove the car for another week without a problem, then it happened again. I came back the next day and it started. The problem became more frequent over the next couple months. If i drove and then turned the car off and then turned it back on immidietly it would start, but if it sat for 10 minutes or more it would stall out, aand then turn over but not start. Come back several hours later or the next day and it would start. The problem got bad enough that the car wasnt reliable enough to drive because of the fear i might get stuck where ever the car was turned off. So the car sat in my driveway for a month. I then went to start it and it started the first try. The car then started evey time for a couple days and then the problem started again so it sat foe another two months in my driveway. I went to start it again and it started the first try, drove it around for a good hour without turning it off. When i got back i turned it off and then back on without a problem. I came back 10-15 minutes later to the problem again, stall out then no spark up at all. The problem got progressivly worse over the next couple weeks and now it wont start at all. I sprayed starting fluid into the intake and it started up and ran until it burned all the starting fluid. I went through the whole can of starting fluid trying to get it to run so i could drive it to a local german car shop, but no luck, as soon as the starting fluid burns out the car stalls out. Someone suggested it may be the fuel pump relay because they can go in and out like that. Has anyone had a problem like the one above? or does anyone know what the problem might be or how to diagnose the problem without running through the whole fuel delivery system part by part? any help or advice would be greatly appreciated