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Fuel Pressure Sensor – find it and fix it!

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Fuel Pressure Sensors –

what is it, where to find it, how to fix it if it goes wrong.

The fuel pressure sensor is a crucial part of the modern common rail diesel system.     The fuel pressure sensor sends information to the engine management unit informing it of the present pressure in the common rail reservoir.
The fuel pressure sensor is probably the weakest component in the electronic control loop. It has to do a lot of work and is prone to failure.

What are the symptoms of fuel pressure sensor failure?

Cutting out.
Failing to start
Running in limp/ get home mode
Erratic running
Engine will run when sensor is dis-connected but will not rev
Engine runs but lacks power

Are all fuel pressure sensors the same?

No there are quite a considerable few differences. There are different makes e.g. Bosch, Siemens/Delphi and Denso.
Different types of Bosch sensors
Mercedes and BMW versus other vehicles
There are differences in the Bosch types fitted to Mercedes and BMW on the one hand and the bulk of other diesel vehicles. Mercedes and BMW Bosch sensors have a different plug design to other sensors fitted to vehicles like Peugeot, Renault and Iveco for example.

Siemens and Delphi
There are a considerable number of variations in the types of sensors fitted on vehicles running the Delphi and Siemens systems.
On the one hand the sensors can have a different pressure rating and on the other hand they can have a different plug configuration. By this I mean the male plug on the vehicle’s wiring loom is specific to the type of sensor fitted. Subtle differences on the male plug have to coincide with the same configuration on the female plug which is part of the sensor.

Denso sensors are fitted to a wide variety of vehicles particularly those originating from companies like Nissan, Toyota and Mitsubishi. They are difficult to source and at time of writing the price from main dealers has tended to be high. Like the sensors already discussed plug configuration does vary from one type to another. In other words the sensor can look identical to another but cannot be used because the plug is different.

Can fuel pressure sensors be repaired?

The typical fuel pressure sensor is a sealed and integrated unit so it cannot be dismantled. In a word they cannot be repaired. Replacement is necessary. Please view   for more information. Contact person Andy Hewing

Where will I locate the fuel pressure on my vehicle?

The fuel pressure sensor is usually located on the end of the common rail fuel reservoir. It is screwed into the rail in a conventional way and is easy to remove and replace. Unfortunately the rail is located in many different places on the many different vehicles. Sometimes the rail is at the front of the engine, sometimes behind. Follow the fuel pipes back from the injectors to locate the position of the common rail fuel reservoir.

Is the fuel pressure regulator different to the fuel pressure sensor?
Yes the sensor is different to the regulator. Some vehicles are fitted with a regulator on the rail. Usually at the opposite end of the rail to the sensor. One easy way to tell them apart is sensor is 3 pins, regulator is 2 pin.

The decline of the Diesel

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Is Diesel in decline?

Lots of diesel cars are bought new. And the buyers are often the firms which buy company cars. They like diesel because its cheap to run and the cars hold their price when time comes to sell them on.

But what about all the new types of cars that are coming onto the market now. There’s hybrid cars; these are often petrol electric. Electric for when you’re in town traffic and petrol to recharge the battery and make sure you don’t get stranded.

Euro 6 emissions regulations are on the way.
Most of these changes are coming along because of the increasingly lower emissions regulations.

Here’s a few factoids to get us started:
2002 – 23% of new cars were diesel engine powered
by 2005 37%, 2008 44% and reached the top in 2011 at 51%.
This year 2013 they have fallen back to 49%. And guess what , its the petrol car that’s pushing them back not electric or hybrid cars. Electric cars are nowhere to be seen accounting for only 1.3% of new car sales!

Why are petrol cars putting in this challenge? Are petrol engined cars making a come-back?

Look around you.
The price of diesel has been higher per litre for diesel compared to petrol for some time. Added to this is the high cost of buying a diesel car in the first place and secondly the higher cost of maintaining and repairing it when it goes wrong or worn parts need replacing.

Petrol is doing well. Lots of people in the know, like the company car buyers, reckon that diesel only makes sense if you’re driving more than 15,000 miles a year
This is truer now as petrol engines have greatly improved in
terms of how fuel efficient they are ,heir performance and their emission levels

Small petrol engine cars like Ford’s Fiesta are good to drive and efficient too and all on just a 1 litre 3 cylinder turbocharged engine. In addition to these qualities these little cars with big performance also produce low levels of CO2 ; vital because both vehicle excise duty and company car tax liability are worked out according to carbon-dioxide emission levels.

There is a lot going on in the development of petrol engine cars that is probably going to be good for some consumers. Part of the problem for diesel is meeting the new emissions levels required by the new Euro 6
emissions regulations. In addition to the rise and rise of small efficient and fun to drive petrol cars there is the phenomenon of the City car. Cars like the Ford Ka, the Fiat 500 and the Citroen C1 as well as VW and Skoda and Kia.

But if you’re a fan of diesel don’t be persuaded that diesel is going away anytime soon. What is probably going to happen is a slowing of the steady growth of diesel that has taken place over the last 20 years
People in the form of customers like diesel. There is a generation of customers who think diesel is the best. They like diesel because of it’s fuel economy, and it’s low down grunt.And just as petrol has evolved so too will diesel. Big companies like Toyota and BMW are developing new diesel designs. It’s good news for consumers that there will be plenty of improvements to chose from as new hybrids come along.

Diesel Fuel Additives – Are they worth adding to your tank?

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diesel fuel onlyDiesel Fuel Additives – Are they worth it?

With very little searching on the internet, it is possible to come across hundreds of adverts for people offering diesel fuel additives with supposed benefits ranging from easier start-ups to increased mileage.

There are additives for diesel fuel specifically, and those that better target petroleum. This article will focus on diesel fuel and will talk about any benefits or problems that can occur when using diesel fuel additives – whether that is on the environment, your car or your wallet.

Additives and the environment:

There are many claims that diesel fuel additives will help make any emissions caused by diesel fuel much cleaner and less harmful to the environment. Some additives are Oxygenates which may reduce the quantity of carbon monoxide emitted by your vehicle, as well as particulate matter and other oxides. This benefit comes from a more complete combustion occurring in the vehicle’s engine.

Additives as cleaners or stabilisers:

Diesel fuel has been known to cause the build-up of carbon deposits, especially in diesel injectors. Many additives work to reduce these deposits and generally clean the engine. Normally, this action is not necessary, especially not as regularly as some suppliers would recommend. Your engine is never going to be more fuel-efficient than its specification allows, so it is wise to be cautious when deciding whether to purchase diesel fuel additives.environment fuel add

Fuel stabilisers aim to keep fuel from ageing badly and going stale. Vehicle performance can be impacted by this – though it is only a concern if you use your vehicle infrequently.

Additives for improved mileage:

Diesel fuel additives often focus on improving fuel efficiency and mileage. The only time that this seems to be the case is if an inferior quality diesel fuel is being used. In these cases, adding additives that can increase the BTU (British Thermal Unit) up to the level of high quality diesel fuels may result in greater mileage. The question is – are you saving money in buying the additives to add to poorer quality fuel rather than just buying high quality fuel to begin with?

There is a lot of information on the web about Acetone being a good diesel fuel additive. It is supposed to increase fuel efficiency, engine life, performance, all whilst reducing emissions. It sounds a bit too good to be true. There are many anecdotes reviewing the use of this kind of additive – with people vouching for and against it. In some cases, it has been thought to be the cause of leaks within the fuel lines.


In Summary:

Due to the contrasting nature of diesel fuel additive reviews and information, I think it is wise to take any claims about them with a pinch of salt. It may be true that some additives have been proven to increase fuel efficiency, but the conditions under which these tests were conducted may be very different to your own circumstances.

Bear in mind that additives are not going to solve underlying problems with your vehicle that may require a trip to the mechanic or new parts. As the name suggests, diesel fuel additives are to be used (if at all) as an extra something, and not as a substitute for good care and good quality diesel fuel.


Can you get more power and more performance from your diesel?

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What is ECU remapping? Does it mean more power from your diesel?

Most drivers know that basic maintenance will keep your diesel engine in the peak of fitness but is it possible to go further than that and improve performance?
Is it possible to remap the ECU and get more power and torque from your diesel engine?

Clive Atthowe Tuning of Norwich here claim that you can. They have teamed up as a tuning partner with Oscarli.

Since 2009 certain cars with Bosch equipment have been fitted with locked or anti tamper tri-core ecu’s.
It is claimed these cannot be remapped.
Clive Atthowe beg to differ:

Tricore  ECUs can be remapped

“people are often told that these new Tricore  ECUs cannot be remapped ….this simply is not true! “

Their website article goes on to say software on vehicles is not “locked”   nor is it  “anti-tamper”  software.

They claim that if you know what you are doing and have the right equipment these latest systems can be modified and tuned to give more power and torque.

They say it is the tuners without the knowledge of the latest diesel systems and lacking the appropriate equipment to deal with tri-core diesel ECU’s who maintain, incorrectly that these systems can’t be modified.

Essential components are things like the diesel fuel pump

If you have a diesel car you will be aware that the essential components are things like the diesel fuel pump, the diesel injectors and the ECU.
The ECU is the brain controlling the performance of the engine.

Of course the engine is sometimes ticking over and at other times pulling hard going up hill or overtaking on the motorway.
The ECU has to provide more or less fuel diesel fuel depending on the demands of the driving situation.

When the diesel car or diesel van manufacturers are programming the ECU they have to aim for an average type of situation.
They will program the ECU to what is recognized as average speeds, average consumption and average power requirements.
The diesel manufacturers do not have the time or inclination to program to get the maximum power and torque from a particular engine; in short they have to be satisfied with aiming for the average.

You can find a competent tuning specialist near you

There are many tuners in the diesel market place who claim they can modify the files in your ECU to give you a greater power output from your diesel engine.

This modification applies to diesel cars and diesel vans from around 1996 on; in fact any common rail diesel vehicle.

The tuner aims to balance “original reliability, fuel consumption and driving style” with an increase in power and torque.

Some, like Oscarli, claim to be able to give you as much as 30 percent increase in power and torque.

Of course in the world of diesel vehicles there are many variations of software. There is software for diesel cars, passenger vehicles, light commercial and heavy commercial as well as marine and agricultural.

Through the power of software controlling the modern engine, vehicles can have speed limiters, power and torque limiters, diesel particulate filters and catalytic converter controllers as well as fault code controllers all built into the software program.

Most of these features can be modified or even deactivated if desired.

Oscarli deals with trade customers only but if you want your diesel car modified you can go onto their website
where you will be directed to your local tuning reseller

Is a diesel vehicle really a better buy?

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Is a diesel vehicle really a better buy?

dieselThe general perception has always been in favour of diesel as a more economic option as far as fuel is concerned.

Experts hold the view that if you have a high usage then the savings accrued in filling the tank can offset the premium price you pay for a diesel model.
However, recent developments are beginning to raise doubts about this viewpoint.

Diesel cars cost more to buy

One of the main points to consider is that though diesel offers more fuel efficiency per gallon, there are other factors that come into play too.

The extra amount that you pay to buy a diesel model is recovered only when you use your car above 15000 miles per year.
Often, if you don’t intend to hold on to the car for long, you will not get to recover the extra initial cost of the car.
A general estimate is that it takes about ten years, if not more, for you to break even.
In addition to this, the real fuel economy becomes more obvious in bigger cars rather than in hatchbacks.
diesel particulate filter

Diesel has lower CO2
A point in favour of diesel is that it does have lower CO2 emissions making it more environment friendly  in terms of your carbon foot print.

But we should not forget that diesel particulate matter and oxides of nitrogen are higher in diesel exhaust.

Another problem with diesel is that the Diesel Particulate Filter (DPF)  fitted is not particularly suited to  urban driving.

In an attempt to reduce the very harmful effects of particulate matter, the introduction of DPF has actually created a lot of practical difficulties for diesel fuel users.

It needs a steady speed of 40mph for at least 10 minutes to heat up enough to burn off the accumulated soot and then you need to drive another 15 minutes for all the soot to be cleared. This can be difficult to achieve ifyou drive a lot in town traffic.
In short, diesel cars are not meant for families that don’t use their car for long hauls. It is more appropriate for companies, if there is a lot of travelling by road.

What about petrol and gas?

There have been some  advances in petrol engines in the recent years.petrol and gas powered cars

Therefore equipped with better technology, petrol cars are now catching up with diesel in fuel efficiency.
As petrol now costs less than diesel too, the benefit that you get from diesel is not as great as it used to be.
In fact, you can say that if fuel economy is your only consideration, even then buying a diesel may not be the better option.

A diesel engine may be sturdier but it has to work under high pressure with a lot of complex adaptations.

This means that it requires regular maintenance like fuel filter changes for optimal performance. In addition diesel equipment like injectors and pumps are expensive of they need to be changed.   On the other hand, a petrol car demands less regular servicing.

However, diesels offer more torque and power than petrol cars.
The verdict now seems to be tipping in favor of petrol cars for limited urban users while diesel would be for people who move long distances or need the extra power that only diesel can provide.