Our family has a 2001 Accord 2.3 automatic - I bought it in 2004, and it’s been passed around our family multiple times due to death and illness. It hasn’t been driven regularly in the last 5 years, but has always “started right up” and been reliable. My younger brother has it now - 5 days ago, we put a new battery in it, and then it started right up. Drove it for several trips over the next 24 hrs and it did fine- ran great. Then it sat for 2 days, and began cranking slowly, couldn’t get it to start, even with a good set of jumper cables. So we put a 15A charger on it, and it appeared to charge fine over 3-4 hrs. Still slow cranking, so we swapped for another new battery, which made no difference. Based on the fact that it was cranking slowly and trying to start, we inspected the starter and ground cables, which look fine. Cleaned the terminals, still no improvement.
So having seemingly checked everything else that could cause a slow crank condition, we broke down and replaced the starter yesterday - no change, still the same very slow crank with each key turn.
We’re completely stumped - what could we be missing, other than battery, starter and probably cables, that could cause a really slow crank? Please help. Thanks in advance!