About a month ago, you described an unsatisfactory experience with the Harbor Freight log splitter, and I suggested a possible explanation. I was right.
Today, I was in my local HF store, and looked at the unit on display there. It is identical to the one I bought at Sears, including having two different control levers for the ram: a speed lever, and a power lever. When standing at the end opposite the splitting wedge, the left- hand lever is the speed lever, and the right-hand lever is the power lever -- a fact which is NOT noted in the HF instruction manual (but IS noted in the Sears manual).
So if you were trying to split logs according to the directions which came with that unit, I can well imagine that it didn't work terribly well.
The *correct* way to split logs with that unit is to advance the ram using the speed (left) lever only, until the ram has pushed the wood into contact with the wedge. Then switch to the power lever, which advances the ram much more slowly (and with correspondingly much greater force).
So you might want to try that again.