engine shutting off

recently just got through w/ helping my friend swap out his motor on his 91 hb. original motor was a 1.5l dpfi. swapped out w/ a ZC SOHC 1.6L that was carb'ed. we only used the block and head. reused intake and exahuast manifold. since we are reusing the original manifolds...there were only 2 sensors, on the block near the oil filter, that needed to be connected on the ZC motor. those 2 sensors were exactly the same as the ones on the original engine. so everything plugged right up. our problem is that once we got the engine in...it started up and ran fine...for about 5 minutes. then it would shut off and would crank but not run. i got code 16. we've check the injectors and resistance for the main inj is suppose to be .6 - 1.6 ohms i believe. we got 2.3 ohms...which i don't think is enough for it to shut off completely. my guess is that it could be the ECM...b/c w/ the ignition on, we sometimes have constant batt power...sometimes none at all. also, i have tried resetting the ECM...it would start up and shut down again. does this sound like the ECM or the injector? the ECM worked fine w/ the original motor. any help would be apprectiated.

forgot to ask if a pm5 ecm from a mfi (4 injectors) car work on my dpfi (dual injector) system? we're having problem finding people w/ the ecm out of a dpfi car...but we know couple people who has the pm5 for the mfi engine. want to hook up a working ecm to make sure it's mine that's fried before buying another one.