1987 Volkswagen Jetta spark plugs

Engine problem
1987 Volkswagen Jetta Engine Size unknown Wheel Drive Type unknown Manual? Miles

My husband is trying to fix up his Jetta and he bought some new spark plugs and it says that the GAP should be on a sticker under the hood. He has 2 jetta's and neither of them have the GAP listed anywhere, so I was just wondering if you knew what is was. 1987 Jetta.