An easy way to check for spark without taking a plug out of the engine is to use a spare plug. Unhook a plug wire from one of the front cylinders and connect it to the spare plug. Lay it on a metal part of the engine and have someone else try to start the car. You should be able to see a spark.
The only way to check the condition of your spark plugs is to take them out and look at them. Since you probably need to do that anyway, you can do the above described test with one of the plugs you pull out of your engine, or better yet, use one of the new plugs you are going to put in your engine.
I would check for the injector pulse by hooking up a volt meter to one of the injector wires while someone tries to start the car. If your reading spikes intermittently, I would say that it is pulsing. Just a guess.
You may also have bad plug wires. I test them by setting the multimeter to measure resistance. Check the resistance through the plug wire, making note of the reading. Make sure the meter leads stay connected to the ends of the plug wire and wiggle and bend the wire. If the reading changes a lot or reads infinity, that wire need to be replaced. All the plug wires should be somewhere close to the same reading, although longer wires will read higher resistance and shorter wires will read lower. It is best to replace all the plug wires at the same time, however if you are sure there is only one that is bad, some parts stores sell them individually.
1990 LE -wrong bumper