86 4runner problem

Ok so I just put a new 4y engine into my 4b, it's now done 20km and died, every time I put my foot down it dies, so I've done a number of things rebuild the carby, new fuel filters, fuel lines blown out, fuel tank emptied and the fuel pump is new also new fuses after all this she fired first go I got 500m and the same thing happened again has anyone got any surgestions as to what it could be???

Check to see that the choke sets correctly cold, before starting.

Check the ignition timing.

Check the intake manifold vacuum at idle, hot. This will detect if you have any vacuum leaks.

Check to see that the accelerator pump dumps gas into the carb when you press on the gas.