What are the common faults of the CNG pressure reducing valve?
3 Answers
Common faults of the CNG pressure reducing valve include: unstable idle speed, poor acceleration; the engine can start, but stalls when switching to gas or fails to switch. Here is relevant information: 1. Common issues: After converting to CNG, certain problems may arise. One situation is that due to the low energy density of gaseous fuel itself, the vehicle can carry less fuel capacity, resulting in shorter driving range. Most natural gas engines currently on the market are modified from gasoline engines, so the power of the vehicle after conversion usually decreases by about 10% to 20%. Moreover, natural gas, as a gaseous fuel, is extremely difficult to store and carry. 2. Device maintenance: Regular device maintenance is essential for CNG-converted vehicles. Due to the special properties of the fuel used, a comprehensive gas leakage inspection should be performed on the gas tank every half month. The inspection method involves thoroughly shaking water mixed with dishwashing liquid and applying it to the vehicle's switches, pressure reducing valve, and other joints. If bubbles are found, it indicates a natural gas leakage problem in the vehicle, and it should be sent to a specialized auto repair department for inspection and repair.
I've been working on gasoline-to-natural gas converted vehicles for twenty years, and pressure reducing valves have quite a few common issues. First is leakage problems - you often see gas escaping or liquid seeping at valve connections, which can make the car hard to start or even cause it to stall. Second is unstable pressure - the output pressure fluctuates wildly, causing the engine RPM to dance around erratically. Third is clogging - when the filter screen accumulates dust, it obstructs gas flow, especially when using impure natural gas. Fourth is aging and wear of sealing rings - they crack or harden after prolonged use. Fifth is improper installation - like misaligned valves or loose fastenings that cause problems throughout the entire pipeline. The causes vary - it could be dramatic temperature changes, excessive usage frequency, or substandard part quality. Prevention is simple: clean the filter screen and inspect seals every six months, and use original equipment parts. Don't delay when issues are found - repair immediately, otherwise it won't just affect performance but could also damage the engine system.
A few years after my car was converted to CNG, the pressure regulator started acting up. The most annoying issue was gas leakage – you could faintly smell it inside the car while driving, and the engine shook violently like having convulsions. Pressure instability was also common, causing jerky acceleration when climbing hills. One winter when temperatures dropped, the regulator froze and the car wouldn't start for hours. Another problem was clogging – the filter screen got completely blocked by impurities, but replacing it fixed the issue. I think sloppy installation easily leads to problems; my friend's CNG-converted car had its regulator fail multiple times, costing a fortune in repairs. I'd suggest adding a protective cover after conversion, paying special attention to insulation during rain or snow, and choosing clean refueling stations. If these minor issues aren't addressed promptly, they could really strand you on the highway at the worst possible moment.
