Sorry could not stay in touch because of being too busy and I see I have missed a generous offer from shaan. I will be very glad and thankful if you post copy of service manual here.
As for my vehicles problems (loss of coolant), my mechanic opened the engine head to check gasket. It was fine. He cleaned the valves from accumulated carbon and put back a new gasket. Never found a problem with anything else. Missing problem is gone, coolant still disappear but at a very slow and manageable rate. I dont know what is wrong.
Then I took the vehicle to Federal Autos and it was a disappointment. He installed a Techometer (Rs 1300/-), high intensity bulbs with relays in headlight and dashboard(Rs 600+450(electrician labour), brake servicing (Rs 200/-), got fuel filter checked, engine tuned(Rs 150/-), spark plugs and air filter changed (Rs 650 + 300). With all this quality of work was so poor that almost everything they have touched had to be worked upon again i.e. Speedometer (they opened dashboard and its connections) started to underead and then failed. Headlights went out of allignement and had to be aligned again. Left front brake stuck at half applied eating up entire brake shoe.(Changed my brakes to Corrola 88 costing about Rs1700/- everything included). Fuel filter was found hanging free with its lines(they even did not bother to clip it back). I now trust my local mechanic far more than I do Federal Autos. I know many people trust them but I can speak for my own experience only. They have the scanner and I may be going there again
Now here is the new problem I have you folks to help me with (especially shaan). When I start my daewoo on CNG RPM starts to fluctuate between 800-1300. After a while Engine Control light comes On and goes off after 15-20 seconds. Light comes on during driving also but always goes off. This is coupled with rise in RPM at its own till 1600-1700 (this happens with Petrol also but Engine light does not come On). If I stop the car in Neutral gear RPM comes back to normal after 7-10 seconds and if I drive vehicle for long say 30 min plus everything goes to normal and stable. As per Owner's manual Engine ligtht coming On briefly is of no significance but this appears to be a malfunction of some sensor may be. I still have old Lovato CNG kit but remember Engine Control light never use to light up earlier with same kit. What do you suggest?