You may need a fuel filter. If the filter has not not been replaced in recent memory, it's a good easy thing to try.
If you want to find a specialist, here's a directory link for you:
https://repairpal.com/infiniti-repair-in-joliet-illinois
RepairPal Certified shops can diagnose and repair your 1991 INFINITI G20. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.