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Mechanical Fuel Pump

Fatima Rangwala
In many non-gravity feed designed automobiles, the mechanical fuel pump is the component which plays a vital role in pumping fuel from the fuel tank all the way to the engine. But can this component always be reliable in terms of performance? Read on to find out...
Heard that you are a regular and a very faithful user of your car?! Time and again the need for you to use your four wheeler occurs, right? Perhaps, you must be maintaining it very well! Many, just like you, are very particular to adapt to preventive measures for maintaining their vehicle.
Well, that's good news as they would never be betrayed by their vehicle in the middle of nowhere! But not all people are so priggish to give their vehicle for maintenance every few months. Such ignorance and carelessness basically leads to several car problems, one of which is a mechanical fuel pump problem.
Although this is the most unexpected and uncommon problem from all the expected ones, it seems that you cannot turn a blind eye since your vehicle has faced one. So the fact is to troubleshoot the problem and repair it at the earliest. How? Look further, but before that let's have a brief discussion on the entire working of the mechanical pump in a vehicle.

Basics and Working

Back in the old days, vintage cars had a fuel pump that worked on the system of gravity as well as on the system of a mechanical fuel pump. In case of gravity fuel pumps, it was just with the help of gravity that fuel would be drawn from the tank to the engine.
With turning centuries since then, today there are rare cars found on road which have this type of a fuel pump system. Almost all the cars made today have a non-gravity based fuel pump, that is they have a mechanical fuel pump which mechanically courses the fuel from the fuel tank to the engine.
And in a similar fashion continuing the flow of fuel, it gets redirected (under eminent pressure) to the fuel injection system and (under moderate pressure) to the carburetor.
Fuel pumps are categorized into two types: mechanical system and electrical system. It's seen that mechanical pump systems are mainly used in ordinary road and driving conditions, whereas electrical systems are usually empowered in race applications.
Speaking of the location of the pump in a vehicle, well, it's mounted on the head of the cylinder or the engine block. These pumps are also called diaphragm pumps which are very flexible in their properties. They are controlled by the camshaft which when rotates also rotates the rocker arm in turn.
This entire movement is shifted to the diaphragm sanctioning the fuel to pump into another chamber situated above the diaphragm. When the diaphragm device moves due to a spring action, fuel is forced out from the pumping chamber into the carburetor and this is how a vehicle functions.

Problems with a Mechanical Fuel Pump

How would you know that a fuel pump has gone bad and you need to undergo a fuel pump replacement procedure?
Well, its easy. If your vehicle refuses to start (rough or low idling), stalls in between, lacks lot of power, all of a sudden the engine stops running, makes noise and so on ... those are the few most obvious symptoms of a bad fuel pump. You can easily run a troubleshooting procedure and resolve all the troubles relative to it.

Ways to Troubleshoot Mechanical Fuel Pump

Before you begin with this procedure gather some basic tools which would be used to conduct the process. Get hold of a screwdriver, an open end wrench and a socket wrench (along with a socket set). Flip open the hood of the car and remove the fasteners around the air filter to get to the carburetor.
  • Next ask someone to press the accelerator of the car while you take a look at the carburetor. What you will see is fuel jetting out of the device. This is the deciding point. If you don't see the fuel forcing out that means your pump has failed and needs a replacement.
  • Another method is to take a look beneath the car and check for any lingering damages or leaks emerging from the pump. If so, your pump has failed.
So here was an article on the working, the relative problems and troubleshooting methods of fuel pumps. It's necessary to ascertain your vehicle's overall condition in every few months so that you put a halt to all the chasing problems (if any) regarding your car.