Were is the fuel modular on a 1990 Chevy 3.1 What would make it surge all the time Replaced everything but the fuel modular?

Were is the fuel modular on a 1990 Chevy 3.1 What would make it surge all the time Replaced everything but the fuel modular?
That year don't have a fuel module. You need to check the EGR Valve. that is the most common problem with a surgeing problem. Is the check engine light on ? if it is ,then you need to have the engine scaned with a scanner and go from there.