Need details, Carburetor or EFI, what kind? Does it cut off clean or does it miss and sputter before it quits? Did it do this before the new fuel pump ? 4 things needed to run, fuel air, compression and ignition, lose any of above and the scenery stops moving. My guess is you have been chasing a suspected fuel problem. If it cuts off cleanly, that's unlikely the problem, more likely an ignition primary problem. Ignition secondary will also miss B4 failure to run. Things to check if not stopping cleanly are fuel pressure under load and at moment of failure, wires,coil, plugs, cap ,rotor. If it cuts off clean, check the primary circuit for wires getting pinched when engine torques on mounts, primary pigtail, if points system, ignition modules and pickup if electronic, wire to ign switch and switch. Now if this is more a power setting failure than RPM issue, again check fuel delivery and ignition secondary items. HTH
Joseppie, November 2008
