How to Fix Jerking During Acceleration in CNG Vehicles?
3 Answers
First, maintain the throttle opening unchanged, then manually adjust the idle solenoid valve and power valve to achieve the highest engine idle speed. Adjust the idle screw to keep the engine at the lowest stable speed. After repeated adjustments, set the vehicle's minimum idle speed under CNG conditions to ensure consistent idle speed between gas and fuel modes, resulting in smooth engine operation.
I've been driving a CNG vehicle for seven or eight years, and acceleration stuttering is mostly due to issues with the gas system. Start troubleshooting from the simplest: Is the gas filter clogged? This part needs replacement every 20,000 kilometers; if clogged, it causes poor gas supply, resulting in jerky movements when you press the accelerator hard. Next, check the fuel rail—inspect the rubber seals for cracks. Aged or leaking seals can affect atomization. Don’t overlook the spark plugs either. Natural gas burns at a higher temperature, so standard spark plugs may develop excessive gaps after just six months. I recommend switching to NGK iridium plugs. Also, check the water circulation pipes of the pressure reducer. If the antifreeze doesn’t flow smoothly in winter, insufficient vaporization can cause stuttering. That’s exactly what happened to my car last time—cleaning the pipes fixed it. Of course, if you can’t handle it yourself, take it to a professional CNG conversion shop to check the gas pressure data and ECU compatibility.
Don't panic when encountering CNG vehicle acceleration hesitation. I've summarized a troubleshooting procedure. First, listen to the engine sound - if accompanied by a 'puttering' noise, it's likely an ignition issue; try replacing the high-voltage wire or ignition coil. If the tachometer needle jumps during acceleration, focus on the gas system: pull out the vacuum tube on the fuel rail and start the engine to check for liquid gas spray, which indicates a ruptured diaphragm. Also, squeeze the gas lines a few times - if you don't feel pulsation, the pressure regulator valve is probably stuck. Another often overlooked point is the oxygen sensor; CNG vehicles are prone to carbon buildup covering the sensor, causing air-fuel ratio imbalance. After cleaning, remember to perform gas pressure self-learning with a diagnostic tool - recalibration usually smooths things out. If problems persist, don't force it; a CNG conversion shop can quickly locate the fault with diagnostic equipment.
