#1 don't check for spark that way. wanna see ya around for awhile
#2 Fuel filter replacement is a must especially if you do not know when it was done last. At the same time replace the check valve at the fuel pump.
#3 Visually inspect the cap and rotor for burn marks etc.. before just buying.
#4 Remove the fuel rail with the injectors attached. Unplug #2-4
place a jar under #1 and crank over and examine the spray. Should be a fine mist. Now uplug #1 and plug in #2 and do the same. Do the same for #3 and #4. Do not just replace injectors on a whim too much $$ for that.
Rick