I've heard that the ATSF #600-series has mechanical fuel injection whereas all C44-9Ws built for BNSF have electronic fuel injection. I guess the rebuilt AC44C4M's have electronic fuel injection too.
I think the rebuilds so far got brand new FDL-16 engines, and I'd expect that these would have electronic fuel injection.
One reason that GE locomotives were rarely rebuilt in the past was that new engines were required to replace the existing engines which suffer from cracks in the cast crankcase after 15-20 years of service. By comparison, EMD units rarely required new crankcases, replacement of power assemblies often being all that was required.
M636C
