1990 Ford Ranger Engine cranks but won't start, good fuel p

Hello,

I have a 1990 ford BroncoII with a 2.9 v6 that cranks great but won't start it does try initially then nothing. Fuel pressure is good 40 psi, strong secondary ignition, have tested all of the wiring between the ECM and sensors and injectors. TFI ignition module tests good. With a noid light on injector connector it will only flash for a couple seconds when the starter is engaged then stops. Good power on positive side of injector harness and to ecm. Also exchanged a matching ecm with no change. The engine will run on either or if you pump the accelerator it will try to stay running without either. Any help would be appreciated. Thanks in advance.