Okay so about a week ago I had my swap far enough along to give it a test bump so after turning it over a few times if fired off and I immediately shut it off ,(no radiator ,or exaust ).Thrilled thinking that everything was going my way I finished in its entirety everything but the hood so I decide to crank it up and back out of the shop and heres where the fun has begun ,my truck will fire off almost immediately everytime but dies within about 2 seconds.Ive discovered that it loses injector pulse .At first I thought maybe it was a mistake in the wiring and the ecm wasn't getting the signal that the engine was running but even if I continue holding the key in the start position it still loses injector pulse after about 2 seconds until I release cut it off and try again.ive tested cam and crank sensors pulled new wires for both cleaned all grounds and even added some extras,changed the core relay to a Bosch ,I'm using the ecm from the automatic 4 runner 2wheel drive 3.4 ltr in my 1990 3.0. manual truck .4x4 any suggestions would be greatly appreciated this is my work truck and very much needed .Also when I scan it I get shift solenoid codes which were expected and I also get p0100 and p0110 and p1300 I've checked and double checked my wiring and even installed new from the sensors back to the ecm but still the codes return

 

I am having similar issues. Haven’t been able to check codes but almost the exact same symptoms.

 

My issue was a broken tooth on the crankshaft timing sprocket.

 

Good on you for reporting back Tropiganda! Hopefully the OP circles back around as well.