Rolls-Royce and Bentley Forums banner

41 - 43 of 43 Posts

130 Posts
1992 k jet Eight is gutless piss poor acceleration on a flat motorway at 70 mph it takes 12 seconds to get to 80mph when foot held to the floor. (Not kick down, just full throttle)
on a wet roundabout car does not have enough power to spin a wheel in anger ! Even using kick down
things tried.
replace fuel filter with genuine Bentley
You know that there is a fuel system issue, but, have overlooked one important item.

TWO fuel pumps are fitted not for redundancy or extra fuel pressure, but, high delivery VOLUME.
Everybody misses this test, even "professionals."
The attached workshop instruction make it a little more complicated than necessary.
Here is a short cut:
Before performing the test, ensure that the battery is fully charged.
Find a two to five liter graduated cylinder. One used for mixing paint is accurate enough.
Find a stopwatch. (smartphone app.)

Remove the fuel pump relay and determine which legs are switched. (30/87?)
Find/make a jumper wire with a suitable wire gauge to bridge the electrical socket to activate the pump.

Find the fuel line that exits the fuel distributor leading to the fuel cooler, disconnect at the cooler instead of "Disconnect the hose from the engine at the one-way valve." This saves you from sourcing an aux pipe and hose, as stated in the manual.

Place the disconnected fuel hose into the graduated cylinder and hold it while you have your assistant bridge the fuel pump relay for 30 seconds with the key off.

The minimum fuel delivery volume is 1.5 Liters/30 seconds. Anything below this commonly equates to a plugged in-tank fuel screen, or both fuel pumps are bad.


169 Posts
Discussion Starter #43
Hi chaps no I have tested the pumps for pressure and flow. It’s one of the first things I checked
41 - 43 of 43 Posts