Common Rail Diesel Fuel Injectors causing you issues? Main Dealer quote too expensive? Look no further, BHP UK Diesel’s here to help!

Common Rail Diesel Injector Issues

BHP UK Diesel is a diesel fuel injection specialist so dealing with diesel injection systems and diesel injection parts is what we are experts at and what we love to do.
If you have a problem with your diesel injector(s), you can send them to us for testing or repair. To help you get your vehicle back on the road as soon as possible, we hold a large stock of diesel injectors for sale, and we’re happy, once payment has been processed, to send out reconditioned or repaired injectors to you.
Please be very careful when ordering fuel injectors. There are alot of companies who offer the service but don’t know what they are doing. We are NOT saying that you SHOULD only use BHP UK Diesel for your diesel injector and other diesel system parts, but we do strongly advise you to make sure you are dealing with a specialist firm.

We can test, repair and overhaul (when possible) virtually all makes / types of diesel injector. This includes:

  • Bosch single stage / double stage
  • CAV single / double stage
  • Denso single / double stage
  • Zexel single / double stage
  • Simms
  • Stanadyne
  • Bosch common rail
  • Delphi common rail
  • Siemens common rail
  • Denso common rail
  • Bosch PD

Please note that due to some injector parts not being available full overhauls are not always possible.

We also have a large stock of diesel injectors for immediate exchange or sale.


Whilst we do carry many injectors for exchange there are a few points to points consider before taking the exchange route.

Injectors can fail for many reasons such as:

  • Fuel contamination (dirty fuel)
  • Damage from particles due to failing fuel pump
  • Engine issues (cylinders overheated)

There are also cases of the injectors being condemned as being faulty and after further investigation the injectors were not a problem. Therefore, BHP UK Diesel always advise customers to have their faulty injectors tested before purchasing new or reconditioned injectors, because in some cases there can be a different underlying problem which can, once fitted, affect or damage the new injectors. This may seem more expensive but can actually save you alot of time and money!

Injector testing and inspection starts from ?5.00 each + VAT.

Some injectors need not be fully rebuilt or exchanged, some may only require recalibration, high pressure flushing or sonic cleaning.

Injector repairs start from ?20.00 each + VAT.

The modern injector is very different to its predecessor. In the past the tolerances allowable were vast compared with those of today. Nowadays, injector manufacturers are expected to produce products that adhere to the strict regulations governing emissions and this has resulted in the nozzles having much smaller bores and higher injection pressures to optimise fuel atomisation. The injector needle will open and close on a commercial vehicle more than a billion times in the course of its service life, and on cars as frequently as 10.000 times a minute. It must also provide a seal of fuel pressure in excess of 2000 bar. The clearance between the nozzle needle and body is 0.002 mm. A human hair is 30 times as thick (0.06 mm) Nozzle bore diameters are 0.12 mm.Modern injectors have become very sophisticated and have more internal parts than before. They rely on diesel for their lubrication. Many failures are caused either by abrasion of the internal parts due to a lack of lubricity or due to the accumulation of deposits on the working parts, notably the nozzle needles and flow valves. Fuel tanks have not changed over the years and condensation remains a problem. Condensation occurs when hot fuel is returned to the cool, breathable, ventilated fuel tank. This results in air containing moisture being drawn into the tank.

Fuel filters are meant to remove the water from the fuel however we see a lot of injectors with rusty internal parts and in the worst cases, nozzle tips eroded off. Water in the fuel also reduces the diesel of its lubricity leading again to excessive wear. In the good old days when an injector developed a fault, the engine would splutter and miss. Now with higher pressures and lower tolerances injectors tend to ‘fail’ rather more dramatically, sometimes resulting in extensive engine damage.

Diesel Injector Testing

All injectors are tested and set up using out Deteq DIT31 Diesel Fuel Injector test bench.

The DIT31 complies to ISO 8984-1 standards. Deteq DIT31 Diesel Fuel Injector test bench

Traditional Injectors
Nozzle opening pressure
Chatter (atomization)
Seat leakage
Back – leakage
Print out available showing Leakage Time and Peak Pressure

Two Stage Injectors
First Nozzle Opening Pressure ( NOP 1 )
Second Nozzle Opening Pressure ( NOP 2 )
Chatter ( atomization )
Seat leakage
Back – leakage
Print out available showing Leakage Time and NOP 1 and 2

Common Rail Injectors
(with the additional signal control unit TC38 )
Leakage time, checking the mechanical condition of the injector.
Injection time, checking the reaction to the command by the ECU
Pressure at injection
Pressure drop, checking the injected flow quantity.
Print out available showing Leakage Time, Injection Time and Pressure Drop.