You should listen.
Its hard for me to come up with a test that requires no skill and no tools and yet I have done this here. You surmise that you have a fuel problem. If you are right a little fuel or starter fluid down the throttle proves it.
If you were right that far then you need to check fuel pressure next. If running some fuel or starter fluid doesn't change things then you have saved a bunch of money and time. It isn't fuel related.
IF its not fuel, testing the ignition without tools will be a little harder.
Bosch Master, ASE Master, L1
33 years MB technician