Well , since you've done some of the items that are on the regular - to check first - list, then you are a step ahead in the elimination game already. That's good.
The fuel pump (I have one on my 126) should last much longer than three years though sometimes they don't. Cleaning mine kept it going for another three years. You might want to change the filter first, while at the same time checking the fuel pump relay, both DIY items and follow that with a fuel pressure test. Good Luck