[DML] Re: "Adjusting" a PRV

["content22207" <brobertson@xxxxxxxxxxxx>]

I beg to differ: in it's original form a PRV is completely adjustable
(including the rocker arms). Later ECU driven systems grafted onto the
original design are indeed non-adjustable, but as those systems become
twitchy or fail altogether, you actually have two choices:
1) Disable systems and adjust manually
2) Return systems to original operation

My Renault Z7V (B27E) was *NEVER* intended for anything automatic
except the CPR, and even then its attendant fuel dampener (located
between the CPR and the fuel distributor) has an adjustment screw:
- Idle speed is adjusted manually 
- Fuel mixture is adjusted manually
- Ignition time is adjusted manually
Oh, original design auxiliary air valve closes automatically, but I'm
burning a manually operated solenoid version from whatever engine is
under the hood of a BMW 530.

Please note that these European spec engines -- every bit as much PRV
as their North American cousins -- don't even have places to attach
the sensors, microswitches, vacuum lines, etc that often cause so much
trouble for aging DeLo's.

That said, I fully concur that a proper tune up with all new
disposable parts is the *FIRST* step. Every new-to-me car is burned
through the engine compartment like General Sherman. All coolant hoses
are replaced (don't forget the thermostat). Remaining vacuum lines (I
de-emission at the same time) are replaced with better quality fuel
line hose. Entire ignition, including the coil upgraded to high
voltage, is replaced (only distributor body and module left
unchanged). Filters, including the oft neglected air filter, are
replaced. You get the idea. It costs $100-$200 up front, but you'll
never get a car to run reliably on someone else's tune up.

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, "David Teitelbaum" <jtrealty@xxxx> wrote:
> You don't get the PRV running by "adjusting" things. If it is not
> running right then it usually means you have to replace or clean
> parts. "Ajusting" the O2 sensor (I assume you messed with the mixture
> screw) only caused you to lose that adjustment. If it won't start than
> you don't begin by messing with adjustments. Start with finding and
> fixing vacuum leaks. Next have the fuel injectors cleaned and do a
> tune-up replacing the spark plugs, ignition wires, cap, rotor, and air
> filter. NOW you adjust the mixture screw on an engine analyzer. In
> fact that is the only thing to adjust unless you also messed with the
> 3 brass screws and the tiny screws on the micro switchs by the
> throttle spool. Timing generally is "right on" or close enough not to
> need adjustment. You do have to make sure the mechanical advance and
> the vacuum advance are working though. If it is smoking a lot pressure
> test the cooling system to find any leaks and do a compression test on
> the cylinders to see if it has been overheated.
> 
> 
> --- In dmcnews@xxxxxxxxxxxxxxx, "painintheass7565" <advantics@xxxx>
wrote:
> > Howdy all.Yup, if you can believe it, VIN 5326 will start but run 
> > ruff after adjusting the O2. You have to give it gas to start it and 
> > keep it running, and she smokes a lot.I remember someone saying that 
> > I would have to adjust the frequency valve once I got it started, but 
> > I don't know how to do that. I'm open to all suggestions. I just want 
> > to thank everyone again for all your help.
> > 
> > John 5326 & 1383




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