The bad accelerator pump symptoms warn you that it is not properly working.
An accelerator pump is an important component in a carburetor. It is responsible for supplying the necessary fuel for a smooth acceleration operation.
However, a bad accelerator pump can cause serious problems for your carburetor. It can not provide additional fuel for your engine system and reduce its performance.
When the accelerator pump fails, it will include some symptoms alerting you, so you must check and fix it immediately. Keep reading the article below for further information.
What Is An Accelerator Pump?
It is a device in a carburetor spraying a gasoline amount under control when the throttle linkage is pushed down each time.
The fuel amount will go into the intake if the accelerator pump properly works to start your engine.
Besides, the accelerator pump also distributes additional fuel in the engine when revving it in certain cases, such as passing another vehicle.
This extra fuel will prevent the engine from stalling or misfiring until the fuel system may meet the fuel flow demands.
How Does the Accelerator Pump on Carburetor Work?
An accelerator pump on carburetor is responsible for delivering the extra fuel to the intake passage when the main throttle valve opens.
A vacuum hose-actuated actuator responding to the manifold vacuum will operate in the manifold runners to actuate the accelerator pump piston during cranking and force the extra fuel into the main intake runner.
Such an extra fuel supply will boost your engine faster when cranking up a cold engine.
Besides, when the accelerator pump actuation restarts a hot engine, it will discard fuel vapors from the system. The fuel supply passages will prepare the accelerator pump for primary operation.
A primary throttle valve will combine with the accelerator pump through a cam. The accelerator pump will supply additional fuel proportional to the primary throttle valve’s opening.
What Are Bad Accelerator Pump Symptoms?
If an accelerator pump has problems, it can create a poor air-fuel mixture for acceleration.
Normally, a faulty accelerator pump can lead to momentary lean conditions with common symptoms such as rough acceleration, engine stalls or sputters, and clogged or dirty fuel filters.
Sluggish Acceleration
One of the most popular symptoms of a bad accelerator pump is sluggish or rough acceleration. The accelerator pump supplies the extra fuel for your engine when accelerating.
If a carburetor hesitation on acceleration happens, it means the pump fails. This will produce a poor fuel mixture during acceleration.
Accelerator pump failure often leads to a momentary lean condition that results in sluggish or slow acceleration or misfiring.
Engine Stalling or Sputtering
Another sign of a faulty accelerator pump carburetor is engine stalling or sputtering, especially when your car stalls in reverse.
The sputtering originates from the lack of fuel that the accelerator pump provides when the throttle is quickly pressed.
If accelerator pump carburetor failure is more serious, suddenly pressing on the throttle may cause the engine to stall again.
This is because the lean condition is created when the accelerator pump stops working.
Besides, a faulty carb accelerator pump also generates a noticeable effect on the engine performance when it is faulty or gets a problem.
If you suspect your accelerator pump may fail, take your vehicle to an automotive shop for a professional technician to check and repair it.
They can also replace your bad accelerator pump and restore proper performance to your car.
Dirty Or Clogged Fuel Filter
The dirty or clogged fuel air filter is one of the poor accelerator pump problems that can ruin your engine.
A filter captures impurities or debris, creating a dirty or clogged condition. This problem can hinder the engine’s capability to get the total fuel amount.
If the pump gives out or gets clogged, it can not supply fuel to the injectors. When your engine runs, this results in sputtering, stalling, or poor acceleration like cars not accelerating over 60 mph.
How To Test Accelerator Pump?
You need to check the accelerator pump to detect potential problems affecting your engine.
Step 1: Warm up your engine by starting it to release clogged debris or impurities. Then, you turn it off and wait a moment.
Step 2: You remove the air cleaner and open the valve. Continue opening the throttle and electric fuel pump wide open for a thorough inspection of the carburetor.
You should inspect a stream or fuel bowl streams squirting in the throat. Check one stream for one barrel carb and two streams for two and four primary barrels.
Step 3: After checking, you can identify the primary problems in the following list.
- The main discharge can lack the check valve, such as check weight or ball.
- A clogged passage can appear from the pump bore to the main discharge. A faulty accelerator pump bore may not be thoroughly filled up.
- The check valve is missing or dirty. Some carburetors don’t have a check valve. They are on the accelerator pump bore top. An insufficient quadrajet accelerator pump adjustment also causes potential carburetion issues.
- The accelerator pump can deteriorate or become the wrong pump if it is not installed correctly.
What Happens If An Accelerator Pump On Carburetor Is Not Working?
The accelerator pump not working is one of the common carburetor problems you must face when operating your vehicle.
A bad accelerator pump can not supply the necessary fuel to make the carburetor work smoothly.
Besides, if an accelerator pump is not working, it can make your engine hard to start.
A faulty accelerator pump can cause a hot carburetor to start your engine more difficult. Such a hot start condition also produces the heat that ignites the shot of fuel lines or carburetor bore.
This leads to a “vapor lock” condition, causing the difficulty of starting a hot engine.
How Long Does A Carburetor Accelerator Pump Last?
The time a carburetor accelerator pump exists also depends on your vehicle’s shelf life and categories.
If you operate a new vehicle, you may not be familiar with the accelerator pump. Most new-generation carbureted cars use an accelerator pump with a fuel injection system.
On automobiles with carburetors, the accelerator pump will regulate the fuel flow to the carburetor to decrease or increase the needed flow of fuel.
Thus, when pressing the accelerator gas pedal, the accelerator pump will distribute the additional fuel for better acceleration.
Conclusion
We’ve covered the bad accelerator pump symptoms that alert the problem your carburetor and engine have been coping with. These symptoms are common and simple to identify.
You need to make an overall inspection of the accelerator pump to determine whether it is faulty or has some problems.
If your accelerator pump is failing or poor, you must take your vehicle to an auto shop for timely repair and replacement.