Surge or Starve — Symptoms of a Failing Diesel Fuel Pump
You may have a finely tuned diesel engine fitted to your vehicle, but it doesn't matter how effective your motor is if it cannot receive that all-important fuel. What kind of problems can hamper your pumping system, what are some of the symptoms, and what should you do if you suspect that you have an issue?
Locating the Pump
There are several different types of pumps. Some are even fitted in the fuel tank itself, while others are to be found underneath the bonnet.
Manual Systems
Your vehicle may be equipped with an all in one system that combines a distributor and a rotary pump. This is operated by the engine, and the drive is supplied by the timing belt.
A variety of problems can arise here, especially when it comes to timing. Such issues are much more commonplace with older mechanical pumps that may require adjustment from time to time.
Electronic Systems
Electronic injector pumps must provide fuel at a consistent delivery rate to take into account the upgraded needs of the modern engine. These pumps are often attached to a common rail injector system which diverts diesel fuel to individual injectors under very high pressure. It doesn't take much for this system to develop problems, and these can often be traced to low-quality fuel or the presence of moisture.
Everyday Failings
Should your diesel fuel pump begin to deteriorate, one of the first signs will be stuttering or stalling during acceleration. You may certainly notice this when you first set off in the morning or when accelerating hard to pass a slower vehicle. In this case, the fuel pump is not able to deliver the right amount of pressure through to the injectors.
Maximum Use
Certain vehicles can cope with a slow fuel pump until they come under increased stress. For example, they may be able to deliver the right amount of diesel for an average situation, but when faced with a steep incline where the engine is under great duress, they won't be able to keep up.
Too Much, Rather Than Too Little
Some people think that a failing pump will always lead to fuel starvation, but this is not necessarily the case. If the pressure cannot be maintained due to failing resistance inside the pump itself, it may flood the system with unwanted fuel. In this case, the vehicle may surge forward unexpectedly.
Challenging the Issue
Should you keep up with regular maintenance, you can often avoid any fuel-related problems. If not, and you suspect that your pump is in need of some tender, loving care, book the vehicle into a mechanic as soon as possible.
Contact an auto repair service for more information.
