What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
How can I repair a fuel pressure fault in my 2000 BMW 530D SE Touring?
What is the best way to solve starting difficulties due to "low fuel pressure delivery" (per diagnostic machine) in my August 2000 BMW 530D SE Auto Touring?
Asked on 30 July 2010 by loughrigg lad
Answered by
Alan Ross
Low fuel pressure is an area in which most fuel supply problems occur. This could be poor fuel supply to the rail/injectors, or the rail/injectors are not holding the fuel within the system. It's best to look at three areas.
1. Low pressure supply from the tank to the high pressure pump (HPP). Some systems rely on the HPP to suck fuel from the tank, whilst others have an electric pump in the tank or fuel line to supply fuel to the HPP. Supply from the tank to the HPP should be about 2 to 5 bars pressure.
2. Fuel is delivered from the HPP to the rail/injectors at about 200 bars during cranking/300 bars during idling.
3. Once the fuel is delivered to the rail/injectors at the relevant pressure it must be maintained within the injectors/rail.
1. Low pressure supply from the tank to the high pressure pump (HPP). Some systems rely on the HPP to suck fuel from the tank, whilst others have an electric pump in the tank or fuel line to supply fuel to the HPP. Supply from the tank to the HPP should be about 2 to 5 bars pressure.
2. Fuel is delivered from the HPP to the rail/injectors at about 200 bars during cranking/300 bars during idling.
3. Once the fuel is delivered to the rail/injectors at the relevant pressure it must be maintained within the injectors/rail.
Looking for a garage you can trust? Honest John's Good Garage Guide has thousands of reader recommended garages, plus how-to guides and tips on servicing.
The Good Garage GuideSimilar questions
I recently bought this 2004 Vauxhall Astra 1.7 DTI diesel estate which, when I first drove it, was nice to drive without any problems. Later on the same day, it started jolting continuously and the revs...
I have read about a possible issue with the Ford C-Max and the fuel filter becoming easily blocked with emulsion, which forces the car to go into limp home mode. This happened to me and with a fuel error...
My wife has a 2009 SEAT Leon FR Petrol. There is an intermittant fault in that when the ignition is turned off and the key removed the engine will continue to run. As this is the DSG verision it can't...
Elsewhere on 
.jpg)
