My Civic 2005 VTI won't start in the morning. The sulf runs very slow and sounds like the battery is down. Tried everything, installed new battery, serviced the sulf, checked all the wiring, serviced the CNG kit etc. I've tried turning it off in cng and also in petrol in the night but the problem persists. Its engine is also in perfect condition but this is quite frustrating. After it starts the first time, its perfectly fine all day. Any suggestions from experts?