Dear sir, I want to asking my Epica Chev 2006 model every morning having hard starting..what is the problem...new spark plug and fuel filter

Possibly there is low fuel pressure. Low fuel pressure would cause hard starting. I would start by having the fuel pressure checked. Possible that the fuel pump is getting weak.

Hello I have replaced the engine of my 2006 epica 2.5.but it won't change the speed on acceleration. When it has to change the it just make a sound like the gear has shift to Neutral back with a sound in the engine. When you drive without speed it will be moving but for the transmission to be able to speed it doesn't work.