Fuel filler release doesn't seem to work

I also have a 94 tercel with this problem. the spring is missing so i tied a long shoestring to the release lever next to the seat. i hold the string and it pulls up on lever while i use my key to open the door the rest of the way. the door pops open enough for the key to fit in the crack. hey it works for me lol have tried to find another spring at wrecking yard but someone always beats me to it

Try this: Have someone pull the release cable. Using a small tool (credit card, plastic knife, anything); see if you can manually "pry" (for lack of a better term) the filler door open. If it DOES open, the fuel door "pop" spring is either broken or compressed to the point that it will not "pop" the door open. The spring is a flat piece of metal, bent into sorta of a "U" shape, and is located at the hinge side. Try this, and get back to me if you need more assistance. Hope this helps.
Toyota Ed