[DML] Brass Manifold Screws vs Centralized Idle
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[DML] Brass Manifold Screws vs Centralized Idle



If I'm not mistaken the whole purpose of idling off the manifold
screws, vs simply cracking the throttle plates like an old fashioned
carburetor, is to take some of the rock & roll out of the odd firing
sequence. If so:

There is no way to properly balance a PRV with CIS only. The idle
speed motor meters both banks equally through the centrally located
cold start tube. Net effect is exactly the same as *VARIABLY* cracking
the throttle plates. 

Nearly all my Renault & Volvo literature is dated 1983 - earlier, so I
may indeed be mistaken Re: late decade blocks. Z7V's and B27E's were
100% manually tuned.

I've yet to find any acronym for fuel injection in my early Renault
literature. Did they later adopt Volvo nomenclature (CI)?

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, Martin Gutkowski <webmaster@xxxx> wrote:
> You're half right. Renault certainly DID employ CIS on later models of 
> their PRVs, my "bible" is the Renault K-Jet manual describing all
manner 
> of permutations of different forms of the PRV's Injection, ignition, 
> fuel and idlespeed systems. I have fantastically thorough fault 
> diagnosis pages (eg proper pin-outs on idlespeed computer), cutaway 
> views of the metering head and full explanations of all the system
parts 
> and how to adjust them _properly_.
> 
> The brass screws on the Volvo 760 are not shear type, the engine has
CIS 
> and the Volvos were set up correctly allowing proper balancing of the 
> banks. Renault also describe the procedure. The DeLorean manual is a 
> simplified system but does not give as much flexibility as is sometimes 
> needed when factory tolerances are not quite spot on (eg centre
position 
> of idlespeed valve). As well as preventing the engine from ever being 
> proerly "fine tuned". The ports are there o the exhaust to achieve it.
> 
> Continued blind acceptance of the DeLorean manual as gospel regarding 
> the idlespeed screws is quite simply wrong. The fine adjustment is so 
> fine in most cases that it makes no noticable difference, but for one 
> car in five, a proper set up of the screws results in a smoother more 
> reliable idle.
> 
> Martin
> DMUK
> 
> content22207 wrote:
> 
> >Note also that Renault never adopted CIS -- it never used shear head
> >style balancing screws. 
> >
> >Interestingly, last weekend I bought an upper air assembly from a 1989
> >B28F that, although CIS equipped, did NOT have shear head balancing
> >screws. Either Volvo itself or a previous owner had adopted John
> >Hervey's philosophy by the end of the decade.
> >
> >Bill Robertson
> >#5939
> >  
> >
> >  
> >




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