I put a crate motor in,about 8 months ago,and had timing set and fuel system cleaned. Ran fine, after about 6 months. It had a loss of power again.replace fuel injectors,tps, and did tune-up. And still no power. Then replace Ecm, I had power after i did that. Then I replaced the mass air flow,the next day, because the engine light stayed on since i replaced motor. When I put The MAF on, and reconnected battery cable. the car was jerking in every gear. then a few mins later, I had loss of power again. Could this be a result in the wiring. Or suggestion what else i should check.

86 camaro. mp fuel injected
2.8L