Fact that is does fire up when gas is poured in would lead me to believe its a fuel delivery problem. Did you pull, check and replace the fuse to the fuel pump?
Fuel Pump Fuse??? Put on your thinking cap...
Some of the more curious problems that the '88 Samurai is prone to is
1. Vacuum leaks (lots of hoses everywhere on the Hitachi Carb).
2. Bad ignitor - an electrical gadget inside the distributor
3. Easily-damaged mechanical fuel pump.
4. Clogged up fuel filter.
Since you get a spark and it runs with direct injection of fuel, #2 can be eliminated.
You said that the fuel pump is new. Assuming that you did not accidently perforate the pump's diaphraghm installing it (It can be done - I did it once...) we can eliminate #3. That pesky fuel pump fuse can be eliminated too!
That leaves vacuum leaks and a stopped up fuel filter.
If you disconnect the inlet hose to the carburetor from the fuel pump and crank it over a bunch, you should get a good stream of gasoline to pour out.
If the fuel pump is busted, the pipe on the side of the fuel pump that does not have a hose on it will be bleeding gasoline (or possibly oil).
If nothing comes out of the fuel line, you have a clog - most likely in the fuel filter.
My guess is that the fuel filter is clogged. It is located inside the passenger rear wheel well on the inside of the frame. Replacing it is not a diffcult task.
Vacuum leaks have to be pretty serious to make the engine not run at all. Nonetheless, you might want to check them out anyway just to be safe. For detailed info on the carb's vacuum system, try a search for vacuum
at Ack's FAQ - the link is in my signature.
I hope that this helps!
PS: Oh, and X2 on what Augeter says too!