Hey laxman
The 94 S-10 would have had the fuel pump in the tank with fuel returning back to the tank. What needs to be done is to remove that fuel pump and install an electric pump behind and outside the tank. A fuel pump which produces 6-8 psi for your carb. Your original pump produces 45 psi and in order not to burn it out, it has to have fuel running through it at all times which returns back to the tank. If you installed a fuel pressure regulator lowering the pressure from 45 down to 7 psi with no provision for a continuous flow of fuel back to the tank, your fuel pump is stalling. This would mean that when the carb shuts off the flow of fuel because the float bowl is full, the pump would come to a stop, and then when the fuel is required and the pressure drops off, the pump can stat up again. At low rate of speed increase, I suppose that the pump can catch up in time, but when a higher rate of fuel is required, the bowl might well be empty prior to the flow starting again thus causing the surging that you speak of. That would be my first guess.

Your problem seems to be a lack of fuel. This could also be from a plugged fuel filter, as was already mentioned. It could also be that your tank is empty. It could also be that your inlet in the tank is too high off of the floor of the tank.(maybe you hooked up to the return line which is high off the bottom of the tank).

I would check for fuel flow at the carb with the engine off, and the hot wire to the distributor disconnected. just so that you don’t accidentally have a spark with the fuel line open. With the original system, the pump would come on for 3 seconds when you turn the key on. Then once you have oil pressure, the pump comes on again. I would eliminate that setup. Let us know how you make out.