Edelbrock 3562 installation instructionsWith the exception of fuel pressure (typically ~42 PSI, depending on altitude and engine vacuum), diagnose MPFI using the same criteria as factory TBI. Did you replace the PROM and place the EST in bypass mode before setting the timing? The PROM is tailored to the drivetrain, so if the original application was very different from yours, drivability issues may result. In addition, Edelbrock's PROM programming concerning those kits was not very sophisticated, rather just enough to pass emissions requirements. Once you have the basics of the system functioning, a custom tune will provide surprising torque and mileage improvement. Have you connected a scanner to it?
1987 Fuel, Drivability and Emissions ManualPay particular attention to anything that will impact manifold vacuum signal to the MAP sensor and FPR, such as vacuum leaks, EGR not closing due to carbon accumulation around pintle or EGR receiving errant vacuum signal from EGR solenoid. Check fuel pressure and verify that the timing is properly set. For anything more involved, you should use a good scanner.