1982mercury grand Marquis
2 Answers
You can check fuel pressure with a mechanical gauge but I doubt high fuel pressure is the cause, it's hard for a fuel pump alone to push the needle off the seat., Much more likely is your fuel pump is sucking up debris from the tank and that is jamming up the needle causing your fuel issues - try a really high quality fuel filter in place of the stock one. If the fuel tank is the original one from 1983, then it could be loaded up with all kinds of crud. (you may even want to drop the tank and give it a thorough inspection and cleaning.)