I owned a carby cultus 2001. Couple of months back, I did engine overhaul after 100K mileage and now having three different problems with my car.
1 - When I start it on CNG in the morning after overnight stop, car vibration is too much especially in the steering. Looks like that some force is shaking whole car. I can understand that its 12 years old car and there will be surely some vibration but what I am facing is extreme. I don't think its a normal kind of vibration. I performed engine tuning from Suzuki some days ago and computerized CNG adjustment from two different shops but problem is still same. One mechanic said its a head valve issue, you need to replace them and it will be OK but head valves are already changed when I did engine overhaul. Is it possible that head valves (made in Japan) stopped working properly only after couple of months they installed?
2- Couple of days back, I was on motorway and decided to check my car max speed on petrol and CNG and at the end I was very disappointed. On petrol without AC, it reached up to 135kph and with CNG needle stopped at 110kph without AC. With AC on both fuels, it didn't cross ~105kph. As I mentioned above, already done tuning and CNG adjustment but no impact on this issue as well. Should I go for carburetor service or something else...?
3- I reckon this as more serious issue, if i start car on petrol while engine is cold, it starts quickly as it should be but the problem arises when I try to start it on petrol while the engine is hot. Engine cranks and try to start itself but unable to start initially. By pressing accelerator again and again, i have a feeling that power from accelerator is not passing to engine to help him in starting.
If i drive say 20km and stop the car and then try to start it again, it will take much more time as compared to if i drive 5km and stop the car and then try to start it. So, problem is severe when Engine is at its maximum temperature. My mechanic is unable to figure out the actual problem, just checking here and there and still have no clue what's going wrong. There is no problem with battery.
I really appreciate for your help to sort out these problems.