Does it sound like it is even trying to start, i.e. does it sound like you are getting any combustion at all? Mine sounded like it was just the starter cranking, no resistance at all, very strong.I barely smell gas in the exhaust now. So it's possible. I tried to crank my engine a few times before pulling them and at least 2 had residue but I chalked it to oil seepage.
Do I need to pull and clean both sets or can I start with the top first and see if it gets it to start at least?
I've never messed with injectors, so I don't know what to tell you there. I know you can get injector cleaner to put in your gas, but that can make the problem worse from what I understand. Supposedly the only proper way to clean them is to send them off for an ultrasonic cleaning - else buy new injectors. Also, still might be electrical on the injectors - think - not sure how to test the circuit for those.
Wibbly most likely has a better answer for you at this point. I'd wait for him.