I have got suzuki alto 2004, purchased 2 years back. I overhauled the engine a year back and it was running fine. In april this year while i was going to office the car got overheated and temp guage went to 3/4th, I immediately stopped the car, opened bonut and found bubbling sound coming from water reservoir bottle and water splashing from reservoir. I waited for about an hour to let the engine cool, but still bubbling sound was coming from bottle, I opened the radiator cap and found it empty. I did not start the car and towed it to my mechanic who overhauled the engine earlier. He said that gasket is blown. He opened the head and found that gasket was ok, despite he put new gasket, and started the car but still same problem (upon giving self bubbling sound coming and engine wont crank). He said that there might be some head facing problem so again he opened the head and sent it for facing to leth machine. After facing the head and tightening the bolts, he started the engine and same problem i.e engine wont start. When u move the key to start the car, at first radiator fat starts then further moving key the engine starts, but my mechanic noted that bubbling sound comes just after the key is moved before actual engine starts. So he diagnosed that water has entered into the CNG regulator, then he disconnected the water pipe from cng regulator kit, switched car to petrol and the engine started. So the problem was water entering into the kit and not the blown gasket. It costed me about 6000 Rs for head facing and opening head twice. My mechanic told me to go and check cng regulator, so I went to a cng shop at gulistanejohar, he removed the regulator and found that there is a crack, so he closed the crack with magic and adviced me to change the regulator. At that time regulator was not available in his shop. Then i went to cng shop at MA jinnah road and he installed second hand genuine italian randi renzo regulator for 6000 rs with 6 months warranty. He also changed the current coil because engine was not starting. Since then I am facing start up problem. In the morning car starts on 3-4 self on cng and when I drive it miss and i had to acclerate hard in order to keep it start, this happens for about 2 km then car runs fine with no jerks. I used to start and off car on cng only. To solve this problem I started the car on petrol then switch it to cng after 1-2 km and there is no missing problem. I went to cng guy and he said regulator is ok, every time i went he did some cng setting i.e fuel idle etc. Last time he said that my carbeurator butterfly is faulty so i went to carbeurator guy he said its ok. I am tired of this problem. The car misses a lot on cng even when i go back home in afternoon, six hours later. I have checked the tappets they are not tight and are fine. Distributor plug wires are also ok. I have registered this car in my name and want to keep it because i know that if i sell the car, it will remain in my name and people will keep selling it and I dont want to risk myself. I hope someone will help me.