setting up idle speed

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Toms820

Member
Posts
71
Location
Polkerris
Hi
Ive recently bought a defender and its fitted with a 3.9 v8. Im currently having issues with the idle speed its seems quiet high to me as when in gear (its a autobox) it will happly chug away at 30 no problems. Is there a ajustment screw for the idle on these i can turn it down abit. Obviously being a defender i have no rev counter so will just have to go off hearing it run.

Cheers tom
 
Hi there, 30mph is way to fast, on the flat the vehicle should crawl along at a very slow working pace I suppose thats around 3 to 5mph.
There's an adjustment screw on on the plenum to set the base idle, the engines ECU will then look after the idle speed which is normally around 650 to 725rpm... that without looking in the manual.
Starting from cold the engine rpm will be around 1100 but will or should drop quick to normal idle quickly.
How to check the base idle and adjust if necessary is in the workshop manual and need a rev counter to do it.
I suppose the throttle and kick down cables are correctly adjusted?.
 
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Ideal thankyou for that information, i shall try and find a manual online and have a look at setting it right.The throttle and kick down seem correct and are very responsive. As for checking the revs my dad has a tool for checking the propeller speed for his nitro planes would that work if i pointed it at the fan belt?
 
The base idle adjustment screw maybe or maybe not under a recessed anti tamper cap, circled in yellow.
 

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A little late but these might help.
 

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  • base idle.txt
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  • 14CUX Install and Diagnostic Information_MarkAdams.pdf
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  • Setting the Air flow sensor_etc.pdf
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  • RANGE ROVER 14cux Fuel Injection system.pdf
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  • 14 CUX ECU WIRING (Small).jpg
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  • Check procedures for the 3.9V8Efi.pdf
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  • ECU on fuel injected engines.txt
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  • ECU_test_data.pdf
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I've had a 3.5 carb (then efi) manual and a 3.9 efi manual and a 3.9 efi auto....all lovely but the auto was extra lovely :cool:
The transplant is a 3.5 from a 92 Disco, sounds great running (on vid) and should haul the 90 around to my satisfaction :D
capo
 
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