1. Fuel pressure regulator: If the fuel pressure regulator is faulty, it may not be able to maintain adequate fuel pressure, leading to the engine running lean and experiencing symptoms such as coughing and sputtering.
2. Fuel injectors: If the fuel injectors are clogged or dirty, they may not be able to deliver the correct amount of fuel to the engine, causing the engine to run rough and stall.
3. Spark plugs: Worn or damaged spark plugs can cause the engine to misfire, which can lead to rough running, coughing, and sputtering.
4. Ignition system: Problems with the ignition system, such as a faulty distributor cap, rotor, or spark plug wires, can also cause the engine to run poorly.
5. Vacuum leaks: Vacuum leaks can lead to a lean fuel mixture, which can cause coughing, sputtering, and stalling.
6. Engine sensors: Faulty sensors, such as the oxygen sensor or throttle position sensor, can send incorrect signals to the engine's computer, causing the engine to run poorly.
To determine if a faulty fuel pump is the cause of your engine's problems, you can check fuel pressure using a fuel pressure test gauge. If the fuel pressure is too low, the pump may be faulty and need to be replaced.
If the fuel pressure is within the normal range, you should diagnose the other potential causes listed above to identify the source of the problem.
