With fuel and spark, well, it should light up. Try some ether (starting fluid) sprayed sparingly (!) down the throttle body. Make sure there's not a mouse nest in the air cleaner or something else weird going on. Make sure the plugs are not fouled. Thump the fuel gauge with your finger, it may jump up, mine tend to "stick" at empty sometimes.

The #4 LED is supposed to blink codes when you press the little button. With the key on, press the button for 3 seconds, and count the blinks. When it stops, press another 3 seconds, count again. If it blinks the same number every time, only one code is stored. If it blinks different numbers, it will repeat (start back at the first numerical code) after you've gone through all of 'em. Blink code "1" means no codes are stored. There are only 8 possible codes on this old CIS system, btw.