my son's 1980 wagon, four cylinder CIS injector system, won't start. Replaced the fuel pump relay and now the fuel pump runs while cranking. I disconnected the battery, removed and cleaned the cold start injector. It sprayed fuel when engine cranking. We thought we had it fixed and he drove it about a mile and the engine quit again, acts like no fuel and the fuel pump still runs. I think there is a problem with fuel pressure getting to the injectors but don't know how to check it. Any help would be appreciated.