The jerking phenomenon under the load condition of internal combustion engines is often directly related to the fluctuation of fuel supply pressure. Bench test data from the Bosch Powertrain Laboratory show that when the turbocharged engine suddenly increased the load by 100% at 3000 RPM, the oil pressure of the original factory standard Fuel Pump dropped sharply from 58 psi to 43 psi (exceeding the ECU regulation limit by ±7.5%), causing the air-fuel ratio to deviate from the target value by 16% instantly. This is the core cause of the jerks. In 2022, Honda’s class-action lawsuit against the 1.5T engine confirmed that the original 190 LPH (liters per hour) oil pump experienced a 23% decline in flow rate in high-temperature environments, resulting in reproducibility jerking faults in 127,000 vehicles when accelerating on slopes.
The flow gain of high-performance oil pumps can fundamentally improve the stability of oil supply. The original 150 LPH pump body of the factory was upgraded to the 255 LPH specification. Its peak flow rate increased by 70%, while maintaining the pressure fluctuation range under critical working conditions controlled within ±3.5 psi (±8.2 psi of the original factory). By increasing the cross-sectional area of the current and strengthening the motor (increasing the power from 85W to 120W), the heat dissipation efficiency has been enhanced by 45%, and the fuel temperature can still be maintained below 60℃ when the intake air temperature is 95℃ (the original factory solution often exceeds 75℃). The measured record of the North American automotive media Car and Driver: After installing the Walbro 255 LPH upgrade kit, the 0-60 mile acceleration jerking frequency of the Ford Mustang GT decreased from 3.2 times per 100 kilometers to 0.1 times per 100 kilometers, and the uniformity of fuel spray particle size improved by 30%.
The precise calibration of the system matching degree is of vital importance. When upgrading, the pressure regulating valve with a precision of 0.1 millimeters (the original factory is 0.25 millimeters) needs to be replaced simultaneously to increase the linearity of the oil pressure curve by 90%. The engineering white paper of Mercedes-Benz AMG Division points out that the modification plan of only replacing the high-pressure pump while retaining the original factory oil rail may increase the pressure oscillation frequency from 120Hz to 450Hz, which instead intensifies the risk of jerk. When used in conjunction with a 10-micron fuel filter (with a 300% improvement in filtration accuracy compared to the original 30-micron filter), it can intercept 99.7% of abrasive particles larger than 8μm, preventing abnormal wear of precision pairs. The real vehicle verification data of the German KTU electronic fuel regulator confirms that the professionally matched 255 LPH upgrade kit can reduce the pressure recovery time when the load suddenly changes from 1.2 seconds to 0.15 seconds.
The economic analysis of the input-output ratio shows its significant value. The cost of the basic upgrade kit is approximately 400 (including 280 for the oil pump, 100 for the regulator, and 20 for the dedicated wiring harness). Compared with the average maintenance expenses caused by bumps (150 for nozzle cleaning, 120 for ECU diagnosis, and 75 for labor), the cost can be recovered within 18 months. J.d. Power user research indicates that the qualified rate of power response for vehicles implementing specification upgrades reaches 953,500.