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V12 RPM

paulreifur
Posts: 17
Joined: Fri Aug 02, 2019 9:49 am

V12 RPM

Postby paulreifur » Tue Mar 24, 2020 10:37 am

I have a problem (at least I think so) when firing at cold speed it is 1500-1600 rpm. After warming up, the turnover drops to 750-800. In addition, everything is going very well, maybe sometimes the spin indicator gently moves. Any ideas what I could check? All wires seem tight. I checked them out. Pacient 1993 Daimler Double Six.

naki_k
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Re: V12 RPM

Postby naki_k » Tue Mar 24, 2020 3:12 pm

That’s a feature, not a fault!
Be happy your Extra Air Valve is actually working.
They can fail meaning your idle gets stuck high
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naki_k
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Re: V12 RPM

Postby naki_k » Tue Mar 24, 2020 3:13 pm

Spin indicator? What’s that then? Perhaps lost in translation?
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NMV 1E
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Re: V12 RPM

Postby NMV 1E » Tue Mar 24, 2020 3:39 pm

Rev' counter ? ;)
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naki_k
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Re: V12 RPM

Postby naki_k » Tue Mar 24, 2020 4:19 pm

paulreifur wrote:I have a problem (at least I think so) when firing at cold speed it is 1500-1600 rpm. After warming up, the turnover drops to 750-800. In addition, everything is going very well, maybe sometimes the spin indicator gently moves. Any ideas what I could check? All wires seem tight. I checked them out. Pacient 1993 Daimler Double Six.


Though having said fact 1500-1600 is a tad high. It should be more like 1300rpm and gradually drops down to normal as the engine warms.
There’s an adjustment nut on the EAV.
Last edited by naki_k on Thu Mar 26, 2020 10:53 am, edited 1 time in total.
88 3.6 XJ6 PDH/CEM
90 Range Rover Vogue SE 3.9 V8 LPG
91 4.0 XJ6 Manual
92 4.0 XJR Manual
92 4.0 XJR
93 3.2s - 4.0 Manual conv
93 4.0 Sovereign
93 6.0 XJ81 DD6 x2
93 6.0 XJ81 XJ12
94 4.0 XJR
94 4.0 Daimler
96 4.0 X306 XJR
96 4.0 X300 D6
97 4.0 X300 Sport Manual
2000 LR Discovery ES TD5 A
Breaking 40/ 300

paulreifur
Posts: 17
Joined: Fri Aug 02, 2019 9:49 am

Re: V12 RPM

Postby paulreifur » Wed Mar 25, 2020 10:50 am

I checked EAV first. Works properly. I did a cooking test :)
The adjusting screw works, but it doesn't help much on a cold engine. Turning it off causes that on a warm engine, the revs come to about 500-600. It works nice quiet :) but the oil pressure drops dramatically.
Is it possible that I just messed up something by installing DAC 4608 coils from Lucas instead of Magneti Marelli?
*spin indicator means Rev Counter. Sorry for the translation.

ChrisW
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Re: V12 RPM

Postby ChrisW » Wed Mar 25, 2020 3:23 pm

Mine has a cold fast idle of around 1500rpm if I haven't used it for a while. Typically this time of year when Its been dormant over winter. Now I'm starting to use it a bit more, after a week or so it reduces to around 1200.
http://www.springballchange.co.uk
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Brake buster
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Re: V12 RPM

Postby Brake buster » Wed Mar 25, 2020 11:24 pm

check the TB butterflies are set to 2 thou of an inch at the top at rest on the adjustable screw caps on the side , without the linkage attached ,

then check the TB linkage is not pulling the butterflies open at rest, not too fine a gap though, as when the engine bay warms the rods lengthen making the revs pick up, also check the linkage is not bent or worn and the rubber bush is in place and intact in the bracket ,

then set the idle valve for 750 revs when warm at idle ,

check for air leaks into the system , especially on the balance pipe and the blanks under the intake manifolds ,

idle should be 1100-1300 no higher really when cold and quickly settle down

BB
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paulreifur
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Re: V12 RPM

Postby paulreifur » Thu Mar 26, 2020 10:05 am

TB butterflies are set as you mentioned.
Rest I will check soon.
Does Lucas coil instead Magneti could change anything?
Thanks for the reply.