Fuel delivery cut out issues just purchased a 91 RX seven built for ITS SCCA racing

Took the car to the track for some testing had a few issues came home changed a few things went back to the track new parts we just installed a brand new hundred psi fuel pump that mounts in side the fuel cell With brand new foam in the cell
brand new primary fuel injectors new plugs new coils

also run an aftermarket fuel pressure regulator and gauge on the firewall in the return side of the fuel system where it comes out of the motor returning back to the tank

now here’s the issue

take the car out runs great for a lap maybe two and then it feels like the motor quit pulling !
like you’ll go to shift gears hit the gas and you can just tell it’s struggling to get fuel and it slowly gets worse until you’re down to first gear at about 10 miles an hour when this happens the fuel pressure gauge fluctuates a bunch and goes all the way down to 10 or 15 pounds

so while it did this on track one time I reach down shut off the fuel pump switch flipped it directly back on in the car took off again like nothing was wrong. So we continued to drive the same problem continue to happen about every lap to lap and a half we would flip the fuel pressure switch off right back on the car would take off again we did this for an hour long in Deuro and every time we flip the switch and a car ran perfectly fine for about another lap

things we changed at the track where we swapped out the fuel pressure regulator the aftermarket one we have installed on the firewall and at the track is where we actually installed the new primary fuel injectors as we only had two with us so we could not change the secondaries

It almost feels like there’s a sensor or relay going bad and when we flip the switch it kills the fuel pressure to the motor lets the relay or sensor reset or maybe the computer reset somehow and then it takes about another lap for it to go bad again any ideas what this could possibly be or has anyone ever ran into this issue before

than it almost feels like there’s a sensor or relay going bad and when we flip the switch kills the fuel pressure to the motor lets the relay or sensor reset or maybe the computer reset somehow and then it takes about another lap for it to go bad again any ideas what this could possibly be or has anyone ever ran into this issue before
thanks
Bryan!!