A residual pressure test is performed several minutes after the engine has been turned off. That leads to a lean mix, which can cause misfires and stalls.How To Troubleshoot A Failing Fuel Pump If your vehicle uses a fuel injection system, a fuel pump (FP) is needed to send gasoline from the gas tank to the injectors. Use an OEM-certified replacement to ensure it lasts for years. While he or she is doing so, listen for the fuel pump being engaged (you'll hear a dampened buzzing sound). It also needs to apply the right amount of pressure in order for your engine to operate efficiently. The pump may cost nearly $250 and the labor can cost another $150 or more. If you can rule out your vehicle's ignition system and the level of compression, the only other explanation is insufficient fuel. An insufficient amount of pressure results in too little fuel in the combustion chamber. First, as mentioned, it must deliver fuel under pressure, and it must do so between a certain range. If the belt appears fine, crank the engine to make sure it turns. When Your Engine Refuses To Start When the FP dies, it can prevent your engine from starting (even if it cranks). If your engine starts, the FP would continue to operate. Each procedure requires a special gauge, which is used to assess the amount of pressure in various circumstances. If the fuel pump is producing a sufficient amount of pressure, it is still possible that it is sending an insufficient volume of gas. If the ignition system is fine, inspect the timing belt; you may need to remove a cover in order to see it. Doing so can be expensive. If it does, that usually means there's sufficient compression. A lack of sufficient fuel can waste water treatment equipment be traced to the pump, the fuel filter (which can be clogged), or a pressure-related issue. The problem is, there are other factors that can produce the same outcome, including issues in the ignition system and the engine. If you determine that the FP has indeed failed, you'll need to install a replacement. To narrow down the culprit, use a spark plug tester (you can buy one at most auto supply stores) to test for spark. Avoid cutting corners with this part. The FP is responsible for two jobs. For example, a running fuel pressure test is done while the engine is idling.. Normally, when the key is turned, the powertrain control module (PCM) engages the FP for a few seconds to build pressure. But suppose you can hear a buzzing sound as the part is engaged. For that reason, you may need to do a volume test. If you are unable to hear the pump working for the first few seconds after cranking your engine, the component has likely died; it will need to be replaced. How Much Pressure And Volume Is Being Produced? Checking the level of pressure generated by your car's fuel pump may require several different tests. In the event your engine refuses to start, the PCM would turn the FP off. This article will provide a few suggestions for troubleshooting and fixing the problem. At this point, the goal is to figure out whether the pump is the problem. This test is performed using a fuel flow gauge that is connected to the fuel line. Checking The Pump Have a friend turn the key in the ignition to crank your engine. Pressure can be affected by a blockage somewhere in the fuel line or too little voltage being received by the pump. Like all components, the fuel pump can eventually fail to work properly. Too much pressure, on the other hand, will waste gasoline, generate pollution, and cause your engine to run rough. Second, it must deliver a sufficient volume of gasoline. That suggests the problem involves a lack of pressure. These include static, residual, running, and dead head pressure tests.
