chrisbrad66 · Nov 30, 2011

Hello all, New member, I'm Chris from Manchester,owned Range rovers and landrovers for quite a few years now. got a niggling fault with my P38 2.5 DHSE. Got a fault code for fuel Quantity actuator, whats happening is when at idle with air con on, the idle bounces from normal to over1100 rpm and back to normal as if i'm blipping the throttle continously, when the air con is off it idles normally with just a hint of a shudder maybe +/- 50 rpm bounce, any ideas? it's a recon pump unit about a year ago and only just started doing it! Also got a glow plug intermittent fault too? any help greatly appreciated

Saint.V8 · Nov 30, 2011

Check Number 4 Injector.....

This injector has a needle lift sensor, which tells the systemwhen the start of the injection cycle is and to start timing its pulses against the Crank Shaft Position Sensor....

The wire to No.4 has a tendaency to get damaged or the lift sensor fails....
Datatek and the Wammer are far more knowledgable on testing and troubleshooting the Diesel, so when they pop online they may be able to help further.

chrisbrad66 · Nov 30, 2011

Thanks for the quick reply, i hope they can help further

matt1987 · Nov 30, 2011

Hi I'm no expert but I've had this recently the fault you have is similar to what I had that fault code relates to your fuel pump when you are on light throttle does it shudder or jolt slighty or come off throttle quick the injector light flashes

To test needle lift sensor remove connector test resistance should be between 90-120ohms I know this as I spoke to the local bosch specialist and that is the first test they do on the injector if that is dud they then tend to test all injectors and check spray patterns

Like said before wammer is the man.for diesels

wammers · Nov 30, 2011

Check the connections to the number four injector and the advance solenoid (under bottom of pump) are clean making good contact and secure. Other than that have pump timing checked.

chrisbrad66 · Dec 1, 2011

matt1987 said:
Hi I'm no expert but I've had this recently the fault you have is similar to what I had that fault code relates to your fuel pump when you are on light throttle does it shudder or jolt slighty or come off throttle quick the injector light flashes

To test needle lift sensor remove connector test resistance should be between 90-120ohms I know this as I spoke to the local bosch specialist and that is the first test they do on the injector if that is dud they then tend to test all injectors and check spray patterns

Like said before wammer is the man.for diesels

no engine light displayed at any time, it revs great and burns clean as a whistle, no jolt or shudder just this dam idle speed bouncing, i'll check resistance and as wammers said solenoid connections under pump, thanks for all the advice, ill keep you all posted

wammers · Dec 1, 2011

chrisbrad66 said:
no engine light displayed at any time, it revs great and burns clean as a whistle, no jolt or shudder just this dam idle speed bouncing, i'll check resistance and as wammers said solenoid connections under pump, thanks for all the advice, ill keep you all posted

Engine speed is controlled by throttle position sensor, engine speed sensor, number four injector and fuel quantity control solenoid working together. Check all the connections first. But maybe the fuel quantity control potentiometer has developed a null point where it gives no signal. But think you said it was a new pump so this should not be the case. If the connection cleaning does not work, maybe you need to get live data read.

chrisbrad66

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Saint.V8

Dyed-in-the-wool 100% RR Junkie

chrisbrad66

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matt1987

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wammers

No longer with us, RIP

chrisbrad66

New Member

wammers

No longer with us, RIP

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