Cat 426B Hard Starting

I have a 426B backhoe that has been hard starting for the 3-4 years I have owned it. Only the initial start is hard each day; once it has run it starts immediately. It runs fine, doesn't burn oil, and rarely produces black smoke. The engine is a Cat turbo 3054 or Perkins 1004 depending on which numbering system you prefer. Shortly after acquiring it the gear drive water pump went out so I opted to perform an in-frame replacement of the engine bearings due to the ethlene glycol in the oil. It turned into a, "while I am at it" project with fresh rings and a valve job. Best I can recall cold cranking compression was around 550 psi, although I am not certain. It has two good batteries with good, clean cables. Running voltage is 13.45, key off 12.40, and cranking 10.75. It spins over quite well. There is no smoke while cranking, with a small black puff upon firing up. This is on 75 degree days. It can take a number of 30 second crank cycles to get it going although it will kick off rapidly with a small sniff of ether. The manifold heater doesn't seem to help during summer temps, although it does make a difference in the winter. The lift pump provides 5 psi of fuel pressure within two seconds of cranking. The injection pump is a Stanadyne DB2. All the filters have been replaced and the fuel suction line to the tank has been blown out. Any thoughts?

Cat 426B Hard Starting