The Physiological Effect of Fuel Pump Failure Over Time A bad fuel pump can eventually damage other engine parts. As the fuel pump ceases to deliver the required fuel to the engine, there is an imbalance in air-to-fuel ratio leading to running lean condition. Higher combustion chamber temperatures are a symptom of a lean mixture, and running too lean will damage essential components like pistons, valves, and the catalytic converter. If combustion temperatures go up 15-20%, that will cause engine parts to wear out faster, cutting the life of an engine by several thousand miles.
Fuel injectors also get affected when the fuel pump is not working properly. Fuel injectors may not adequately discharge fuel with poor combustion, and insuffient fuel pressure. In other cases, fuel injectors could become clogged or fail altogether and that will be very expensive to fix. On average fuel injectors cost $300-$500 per injector to replace making that another super expensive result of a bad fuel pump. 2015 was particularly troubling when one of the largest car makers had to recall thousands o vehicles with misbehaving fuel pumps causing widespread injector trouble.
The oxygen sensor is all but guaranteed to be at risk with this junk. An unstable fuel pump provides an incorrect mixture of air and fuel through the engine operation causing unburnt fuel to destroy the sensor over time. While oxygen sensors are usually good for 60-90K miles, they can go bad much earlier if a fuel pump goes sour; by as much as 30%. Furthermore, the cost of replacing an oxygen sensor is usually between $100-300, hiking even further the overall maintenance costs.
The adverse effects of a bad fuel pump on the catalytic converter are even more severe. A vehicle that runs lean or rich can send out unburnt fuel to the converter which will decrease its operating limit, melting if it is hotter or incompletely burning fuel. This blockage hurts engine performance and increases the level of emissions, which is exactly what the catalytic convertor is there to help pupils from. Catalytic converter replacement: The cost of a catalytic converter replacement can range anywhere from $1,000 to$2,500 to fix a failing fuel pump and considered being the most expensive repair item.
In addition, inadequate fuel delivery puts extra strain on the ignition system which can lead to spark plug breakdown before they are due for replacement. Misfires are caused by flow problems disrupting the spark plugs, which ignite the gas/air in an engine's cylinders. The result is up to a 15% loss of power, decreasing fuel efficiency and crispness of acceleration. As much as spark plug replacement is a relatively cheaper cost (around $100 – $200), which expenses may still mount if the fuel pump is not performing properly.
For additional information on upkeep and repair of a gas pump visit Fuel Pump.