Question about Cars & Trucks

Open Question

Rolls-royce problem why is the brake pressure light on

Posted by on


6 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 88 Answers

SOURCE: how do I reset "service recomended" warning light please

take it back to the shop and get them to do it as they have the gizmo

Posted on May 20, 2009

  • 63 Answers

SOURCE: I need the operating fuel pressure for a 1989

Here it is and all the info you would ever need on the bosch k series.
spacerline.jpg “ This tech told me that the only way the fuse would quit blowing was by unhooking the coil pack. I was stunned at first, since the power to the coil is through a red/light green (R/LG) wire and from a different fuse than the solid red. ” ---> The K-Series fuel injection systems are continuous mechanical fuel injection systems used on a wide variety of European vehicles, including such makes as Volkswagon, Audi, BMW, Mercedes, Porsche, Volvo and Saab. The system is one of the most common fuel injection systems on the market today, but also is one of the least understood.
The K-Jetronic System constantly injects fuel into the engine as long as the car is running and air flow is present to move the sensor plate in the airflow sensor. The sensor plate is connected to an arm that pushes up on a plunger located in the fuel distributor. As airflow changes, the movement of the sensor plate and the plunger increase and decrease the volume of fuel injected into the engine. Since fuel is being injected constantly, fuel pressure will have a direct affect on driveability. As a matter of fact, fuel pressure is the single most critical element when diagnosing driveability problems in the K-Series fuel injection systems. An accurate fuel pressure gauge must be used when testing these systems, with a range of 0 to more than 100 psi. You will also need a digital volt ohm meter (DVOM) that can read milliamps.
You will work with three types of pressures when diagnosing these systems: system pressure, control pressure (also known as counter pressure) and rest pressure.
System pressure is the total fuel pressure produced by the fuel pump on a constant basis. The fuel pump must be able to maintain this pressure during all driving conditions from idle to wide open throttle. As a rule, system pressure will run about 5 to 5.5 bar pressure, or 75 to 85 psi (1 bar = about 15 psi) and the pump should be able to produce a minimum volume of 1 pint in 15 seconds. When deadheaded, the K-Series fuel pump will produce about 1.5 times the system pressure or about 110 to 120 psi. System pressure is a function of volume of fluid moved against a restriction, so to maintain system pressure at the desired level, there must be some type of restriction built into the fuel system. This restriction is more commonly known as the fuel pressure regulator. The fuel pressure regulator restricts the return of fuel to the tank by a calibrated amount, maintaining system pressure at the desired level. On early K-Jet systems, this regulator was a slide valve (also known as a push valve) internal to the fuel distributor. Fuel pressure could be adjusted by adding or removing shims from the valve. On later K-Jet systems, the regulator is the conventional diaphragm type.
Control pressure (or counter pressure) is the pressure that is metered to the top of the fuel plunger on a K-Jet system. By changing the counter pressure, the resistance to plunger movement is changed, allowing enrichment and enleanment of the fuel mixture to the engine. On a car equipped with K-Jet, this pressure is controlled by the warm-up regulator.
The warm-up regulator only compensates for engine temperature and is therefore a rather coarse control of fuel mixture. (Some K-Jet warm-up regulators also have a vacuum port to help with the acceleration enrichment and deceleration enleanment function.) Typical control pressures on a K-Jet warm-up regulator are 55 psi with the engine at full operating temperature and 20 to 30 psi on a cold engine. (The colder the engine, the lower the pressure.)
A car equipped with K-Jet Lambda also changes control pressure with a warm-up regulator (with pressures similar to a plain K-Jet system), but also controls lower chamber pressure in the fuel distributor by bleeding pressure through a frequency valve. By modifying lower chamber pressure, a change in volume of injected fuel is made, enriching or enleaning the mixture. The frequency valve is nothing more than an electrically duty-cycled fuel pressure regulator controlled by an on-board computer in response to an oxygen sensor signal. This system provides a more precise and rapid control of fuel mixture. Typical duty cycle on a properly running engine is 45 percent to 55 percent duty and fluctuating. A quick test of this system is to start the engine and test the frequency valve for vibration or noise -- it should vibrate. Also, unplugging the oxygen sensor will put the system in open loop and fix the frequency valve at a 50 percent duty cycle.
The KE-Jet system provides quicker response and more precise control of fuel mixture than the K-Jet Lambda system and is the current K-Jet system in use. This system uses a device called a differential pressure regulator to control fuel mixture in response to both engine temperature and oxygen sensor signals. In the KE-Jet system, counter pressure is broken down into primary counter pressure and control counter pressure. Primary counter pressure is the pressure applied to the top of the fuel plunger. This pressure stays constant and is the same as system pressure.
Control counter pressure is modified by the differential pressure regulator and is actually the lower chamber pressure in the fuel distributor. By modifying lower chamber pressure, the fuel mixture can be enriched or enleaned in response to temperature and oxygen sensor signals. Typical control counter pressures are 4 to 7 psi less than system pressure on a fully warmed engine and 17 to 20 psi less than system pressure on a cold engine (typical system pressures are 5.0 to 5.5 bar or 75 to 85 psi). The signal to the differential pressure regulator from the computer is measured in milliamps of current. To test this signal, a DVOM must be placed in series with the differential pressure regulator. Typical current values are 80 milliamps cold engine (15k ohm resistor in place of coolant temp sensor to simulate a cold engine condition); 120 milliamps during cranking (this is a crank enrich function to aid starting); and 8 to 12 milliamps warm idle. (Note: always check service manual for values.) These values correspond to the fuel pressures listed. In other words, at 80 milliamps current you should show 17 to 20 psi less than system pressure.
Rest pressure is the fuel pressure maintained in the system by the fuel accumulator after engine shutdown. The fuel accumulator is a large spring-loaded diaphragm that maintains a pressure of about 1.5 to 2.0 bar for 30 minutes or more after engine shutdown. This rest pressure provides for fast restart and prevents fuel percolation or boiling (vapor lock). Always check the service manual for the car line you are working on for proper rest pressures and times. Typical symptoms caused by accumulator problems are extended crank time and hard start hot.
With an understanding of the system and the proper tools, K-Jetronic fuel system service is a straightforward procedure that can keep your service bays full all year long. Give me a call if you have any questions!...did this help? Let me know...dc

Posted on Jun 24, 2009

  • 1 Answer


Right Bank A, Left Bank B A1 B1 A4 B4 B2 A3 B3 A2

Posted on Jan 15, 2010

SOURCE: I want a picture of the brake pipe layout on a

Try They sell manuals,

Posted on Jan 30, 2010

  • 10865 Answers

SOURCE: how to reset rolls royce phantom oil service

Hello. most times you reset by turning on the ignition but not starting the auto, then quickly push the gas pedal three times. J.

Posted on Jun 16, 2010

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

Rolls Royce Shadow 1 brakes fade and come back after parking for a while.

That's easy, tyou most likely need a new master cylinder, remember to use the coorect mineral based brake fluid with this brake system.

Jan 22, 2014 | Cars & Trucks

1 Answer


Go to tire pressure and press reset on the status:tpm active

May 21, 2013 | 2007 Rolls Royce Rolls Royce Phantom

1 Answer

1986 rolls royce silver spur brakes do not work

When u push on the brake pedel does it go to the floor. If so u have a leak somewhere. If not possible master cylinder. It will use Dot 3 brake fluid.

Jun 14, 2012 | 1991 Rolls Royce Rolls Royce Silver Spur

1 Answer

1991 rolls royce brake fluid

The fluid for these cars should be GTLMA by castrol. Anything else will contaminate and destroy the system causing a huge safety concern.

Jul 23, 2011 | 1991 Rolls Royce Rolls Royce Silver Spur

1 Answer

1990 silver spur gear shift will not release from park. i checked to see if i have brake lights working and they are. help please

The shifter has a shift lock solenoid that works when you apply your foot on the brake to shift out of PARK. That soenoid has gone bad. Most starter rebuilders can rebuild these

Nov 15, 2010 | 1991 Rolls Royce Rolls Royce Silver Spur

1 Answer

Where is the switch for the brake light in Rolls Royce Silver Spirit 1986

hello there
the switch should be located on the brake pedal arm there should be a pin and or a clip to hold it on the arm you should also have a plug on the switch...hope this helps thanks

May 30, 2010 | 2007 Rolls Royce Rolls Royce Silver Spirit

1 Answer

'97 oil pressure sending unit

PT1801-06 Smith's, can be ordered through autoparts warehouse for under $75. Rolls Royce runs about $145. Should be pretty easy to replace.

Mar 25, 2010 | 2005 Rolls Royce Rolls Royce Silver Spur

1 Answer

What does it mean when the oil pressure indicator

The oil level may be normal, but the light coming on means there's an issue. There's probably an issue with the pressure and it's detected a leak somewhere

Sep 09, 2009 | Rolls Royce Silver Spirit Cars & Trucks

1 Answer

No brakes 1989 silver spur. abs system

Unfortunately everything except the metal pipes.

Best bet is to buy a set of used ones off a breaker car. Buy new hoses, high pressure and low pressure ones.

Jul 03, 2009 | 2007 Rolls Royce Rolls Royce Silver Spur

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

20 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cars & Trucks Experts


Level 3 Expert

76649 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22219 Answers

Randy Ohler

Level 3 Expert

14585 Answers

Are you a Car and Truck Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides