Engines need fuel, spark, air...

A favorite trick of mine is for someone to spray engine starting fluid (get at automotive store) into the engine air intake as someone else starts the engine. You will get a response from the engine if there is a fuel problem.

And as stated above, some fuel pressure is not enough, it needs to be a certain pressure - properly test with a fuel pressure tester (Harbor Freight sells a kit which includes Bosch Jetronic adapters for not too much $$.)