Many people complain about a weak fuel pump on efficient 7.3 Powerstroke engines of Ford trucks. The fuel pump draws 5 to 7 PSI from the fuel tanks, supplies it to the separator, and delivers 50 to 80 PSI to each injector.
How to Detect Weak Fuel Pump on 7.3 Powerstroke? You can detect a weak fuel pump on 7.3 Powerstroke by power reduction and idling, transmission failure, engine revving, low PSI value and warning light, challenging acceleration, stalling, damaged fuel filters, and low fuel bowl level.
The weak fuel pump shows various signs on the engine performance. I have detected low PSI (pounds per square inch) and the engine revving more frequently.
How do you detect a weak fuel pump on 7.3 Powerstroke?
Its weak performance has several symptoms. I have explained the most significant signs of its malfunctioning on a 7.3L Powerstroke.
Power reduction and idling
The engine loses power gradually when the fuel pump becomes weak. As a result, the engine loses its performance and cannot provide the horsepower for acceleration.
You can turn off the motor for about 5 to 10 minutes. Then, you can restart the motor. It can stabilize the power flow for a few minutes.
The power flow reduces after 5 to 7 minutes, which reduces acceleration while driving the pickup truck. It is a significant symptom of its inefficient performance and malfunctioning.
It fails due to continuous power loss. The motor loses its stability and malfunctions. In addition, the reduced power decreases the fuel flow inside the engine.
It increases the engine idling when you start it. The rough and continuous idling reduces motor efficiency and causes various mechanical damages.
A primary symptom of a weak fuel pump is the failure of truck transmission. You cannot shift the gears according to your requirements when the fuel pressure decrease.
Transmission failures and vibrations become significant. In addition, you cannot change the gears because they become rigid.
Their shifting becomes complicated and excessive force can break these gears. As a result, the motor failures increase, and the dashboard indicates various warnings about the transmission failure of the truck.
The weak and damaged fuel pump can cause revving. It can rotate the engine at about 2500 to 3200 rotations or minutes (RPMs).
These revs are higher than the standard level. As a result, it can increase the internal heat of the motor. Thermal changes affect motor performance and cause mechanical damage.
The horsepower increases beyond the threshold at this torque. Excessive motor revving is dangerous because it results in overheating.
It cannot withstand these higher rotations. It causes sputtering of the motor.
The engine rotations vary, and surges become significant. Excessive motor surging leads to its complete failure.
Higher revving indicates its failure because it increases the temperature.
Low PSI value and Warning light
The 7.3 Powerstroke has a 32 to 34 PSI (pounds per square inch). However, it can reach 40 PSI according to its performance and fuel flow.
The hood of the pickup truck has a pressure gauge and meter. You can read the PSI on the meter.
The sign of a weak fuel pump is a periodic reduction in PSI. It can change the mixture of fuel and air.
It leads to a misfire, and ECM (electronic/engine control module) detects the failures. The fuel sensor can find its reduced performance and trigger a P0190 code.
Its malfunctioning triggers a check light which shows its weak performance. It malfunctions and cannot stabilize the pounds per square inch of the pressure.
The check light is a warning sign that illuminates to warn about motor problems and defects.
Challenging acceleration and stalling
The fuel pump supplies fuel to the engine cylinder and its block. However, it becomes weak and cannot carry out this function.
Its pressure decrease and reduces the truck’s acceleration. Therefore, a sudden reduction in the standard truck acceleration indicates its failure.
You cannot change the acceleration according to your convenience. For example, you cannot handle it while driving the pickup truck.
Another symptom of its weak performance is excessive motor stalling. The fuel flow reduces and alters.
It does not reach the injectors and motor stalls. The combustion modifies and causes stalling of the engine.
Damaged fuel filters
The fuel filters clean the fuel and stabilize its performance on the 7.3-liter Powerstroke. However, dust can clog and contaminate these filters.
They lose their standard efficiency and performance. Engine misfires are common signs of a weak pump when the fuel filters clog.
They cannot stabilize the performance of cylinders and combustions. The filters malfunction and require a replacement.
The damaged filters cannot stabilize combustion, which changes speed patterns on the pickup trucks. Variable speed indicates malfunctioning of the filters.
They damage when it becomes weak on the engine.
Low level in the fuel bowl
The fuel injection system of the 7.3L Powerstroke works with a fuel bowl. The pump delivers fuel through injectors, and this bowl collects it.
It remains filled with fuel for its stabilized performance. It becomes weak and cannot inject specific fuel into this bowl.
Its level reduces from the peak levels. Therefore, it does not inject fuel into this specific bowl during ignition.
You cannot stabilize the fuel bowl level, which affects the ignition. As a result, starting the pickup truck becomes challenging and indicates its failure.
What are the causes of the weak fuel pump on 7.3 Powerstroke?
Several external and internal factors can affect and reduce its performance. I have explained the causes of its malfunction.
Damaged fuel lines and filters clogging
The pebbles and large stones can hit the fuel lines of 7.3 Powerstroke while you drive the pickup truck at fast speeds. The pebbles can damage the flow lines and squeeze these pipes beneath the truck frame.
The fuel pressure decreases, and the pump malfunctions. In addition, dust-containing air can clog the fuel filter and reduces its efficiency.
It cannot clean the fluid, and a clogged filter reduces combustion. Decreased fuel pressure can cause low acceleration and engine failures.
Voltage issues and broken regulators
This engine has sensors that regulate and identify the fuel pressure. In addition, they can identify the changes in its flow properties and speed.
They are electrically regulated sensors. As a result, voltage changes, broken wires, and damaged connectors can reduce sensor performance.
The pump becomes weak and cannot maintain fuel pressure. The pressure regulator breaks due to incorrect pressure and internal heat.
The fuel pressure becomes high or low when the regulator breaks. As a result, the regulator cannot connect with the Powertrain control module, which affects acceleration.
The low external temperature can affect the fuel pump performance on the 7.3-liter Powerstroke. The motor becomes cold, and fuel pressure reduces.
The values change on the pressure-checking gauge. This is because variable temperatures can damage the pump on this engine.
It cannot supply fuel at a specific speed to all the components. However, you can run the motor for a few minutes, and it increases the temperature.
Sometimes, the external temperature increases and affects the fuel pressure. In both conditions, it loses its stable performance.
How to troubleshoot and fix a weak fuel pump on 7.3 Powerstroke?
You can troubleshoot the weak fuel pump by checking the fuel pressure. You can use a pressure gauge to identify its flow and pressure.
Visual examination of filters is necessary and removes clogging. You can replace it with or without mechanical help.
You can find it on a 7.3-liter Powerstroke frame rail. It is on the driver’s side of the pickup truck.
You can hold its mounting clip and remove it. You can adjust a pocket correctly sized screwdriver for the clip removal.
Then, you can remove the flow lines from the motor. Finally, you can hold the electric wires and pull and remove them from the engine.
You can clamp the specific tool with its front side. Rotating the tool can loosen it.
You can adjust a container under it and drain it. Removing the clips from the flow passages is essential for their removal.
You can remove the old, weak, malfunctioning pump and add the new compatible option. Then, you can install the new flow lines on its back and front.
You can utilize the locks to secure it in the mounting place. Then, you can use a ratchet and fix the bolts.
Re-connecting the electric wires is essential because the engine has electrically operated fuel injectors and flow passages. You can run the engine and fill the bowl to stabilize the pressure.