My dad has a 95 riveria (which he loves) but the door does not release properly for access to the fuel cap. There appears to be a small plunger within a larger plunger which catches and holds the door shut. The larger plunger does not retract when you hit the button, but is it supposed to do so?? The small plunger does retract a little bit.
I have tried very gingerly to bend the "hasp" of the door to see if that could help, but this does not do anything either. Lubricant does not solve this particular problem either.
At the very least he can pull the line from inside the trunk, but I'd like to get it fixed for him permanently.
Any ideas??? Is the dealership going to get some money on this one?!?!
Sounds like the fuel door actuator.
Number 11 in illustration.
I am pretty sure only the dealers carry these, if you go to a dealer ask for part number 25650076 see if they have it and see if is what you need.
Also here is a GM bulletin I found for you pertaining to the spring that assist the actuator in opening the door.