gas cap fitment problem
09-25-2022, 07:52 AM
#1
gas cap fitment problem Hi All:
I recently purchased a 94 Trans Am convertible anniversary ed with 400 miles . The car was delivered in very good condition and ran well . I was transporting the car from one storage location to another and stopped to fill the tank and add stabil . I noticed that the gas filler cap was initially not on properly and would not seat properly at the end of the fill . I ordered and OEM gas cap replacement . The replacement gas cap was identical to the gas cap that came with the car and neither fits .
The diameter of the cap and filler neck seem correct but ,looking at the thread pattern of the OEM cap there are about three threads along the length of the cap each about 1/4 to 3/8 inch apart . Looking at the threads inside the current filler neck there are a few threads that appear to only go about 90 degrees and go in about 1 inch in depth . Like 1/4 turn would seat the cap not the 3 turns needed for the OEM cap to seat . ( Sorry , difficult for me to explain better than that ) .
So went on line to see if anyone else has had issues similar to this . Best that I could come up with is that the car has had an after market tank placed ( probably due to the car sitting its whole life ) and the filler neck thread pattern is different than OEM .
I would like to find a gas cap that would fit . If anyone had a solution it would be greatly appreciated .
Thanks
Marty
I recently purchased a 94 Trans Am convertible anniversary ed with 400 miles . The car was delivered in very good condition and ran well . I was transporting the car from one storage location to another and stopped to fill the tank and add stabil . I noticed that the gas filler cap was initially not on properly and would not seat properly at the end of the fill . I ordered and OEM gas cap replacement . The replacement gas cap was identical to the gas cap that came with the car and neither fits .
The diameter of the cap and filler neck seem correct but ,looking at the thread pattern of the OEM cap there are about three threads along the length of the cap each about 1/4 to 3/8 inch apart . Looking at the threads inside the current filler neck there are a few threads that appear to only go about 90 degrees and go in about 1 inch in depth . Like 1/4 turn would seat the cap not the 3 turns needed for the OEM cap to seat . ( Sorry , difficult for me to explain better than that ) .
So went on line to see if anyone else has had issues similar to this . Best that I could come up with is that the car has had an after market tank placed ( probably due to the car sitting its whole life ) and the filler neck thread pattern is different than OEM .
I would like to find a gas cap that would fit . If anyone had a solution it would be greatly appreciated .
Thanks
Marty
09-26-2022, 06:24 AM
#2
TECH Junkie
If the GM cap does not fit you will need to find out from the seller what's going on. Otherwise you will be guessing forever and throwing $$$ out the window trying to find what fits properly.
I personally have not read much about other Firebird owners having this issue. A 400 miles car having the gas tank replaced is odd to me unless it was kept outside or in a poor environment. Could it just be the filler neck area? Again, only the seller will be able to tell you anything unless another member here has had the same experience. Good luck!
I personally have not read much about other Firebird owners having this issue. A 400 miles car having the gas tank replaced is odd to me unless it was kept outside or in a poor environment. Could it just be the filler neck area? Again, only the seller will be able to tell you anything unless another member here has had the same experience. Good luck!
10-19-2022, 02:29 PM
#3
TECH Fanatic
here is a link to a filler neck from this site sponsor RockAuto . It appears the car does have an incorrect filler neck. Another possibility would be to take the car to an auto parts store and see if they will allow you to try some caps 