A failing fuel pump can cause the engine to start misfiring due to disruption in the delivery of fuel towards the combustion chamber. If a pump cannot keep the fuel pressure constant, the balance of air-fuel may be disrupted leading it to burn inefficiently and most likely not combust at all. Low fuel pressure, determined not even remotely by a gauge but rather a study of manufacturer specs, drops well below the 30–80 psi range and leads directly to engine misfires. For example, if a car’s fuel system requires 50 psi for the engine to operate properly, and the pump is only able to deliver 20 psi, then the car will misfire.
Misfires from fuel pump problems are often accompanied by symptoms such as jerks or hesitation during acceleration. According to automotive repair data, as many as 15 percent of complaints about poor engine performance such as misfiring lead mechanics to failing pumps. This issue is often blamed on clogged fuel filters or ancient pump components by auto techs. If a filter is beyond its recommended service life (20,000-30,000 miles), it restricts fuel flow, working the pump harder and increasing misfire potential.
Volatility in the electrical supply for the pump can also lead to misfires. The Fuel Pump works to its prime power with 12 volts, while corroded wiring or damaged relays often reduce the voltage provided. Insufficient voltage does not allow the pump to deliver fuel at the required rate, resulting in an intermittent misfire particularly under load. According to reports from the industry, electrical issues account for around 10% of all pump-related failures.
Fuel injection systems make pump issues especially critical for high-performance engines. They need to have the correct amount of fuel at each start up in order for combustion to be efficient. If pressure changes or flow rate differs, injector timing is disrupted and misfires occur. Von Bosch) The second time-out sits with Bosch, which is a big player in the automotive tech arena worldwide, and points out that holding steady in terms of fuel delivery is imperative for engines using sophistricated injection technology.
Examples in the wild 2: Fuel pump issues lead to misfires An actual case study from an AAA repair center showed a 2015 Ford Escape that was suffering repeated misfires because the pump only operated at 60% efficiency. So we simply replaced the pump, and that was it; no misfire anymore, that’s for sure!
Routine maintenance also minimizes engine misfire by inspecting the fuel pump, fuel filter and electrical connections on a regular basis. The pump is ensuring that it is giving a stable pressure so their will not be added tension on the other things and performance of the engine then goes better. Identifying and resolving the concerns of a pump follows on in the course can spare drivers immense expense, while lessening repairs through the life of the vehicle.