[DML] Re: automatic in Park [was: Lambda system]

["David Teitelbaum" <jtrealty@xxxxxxxxxxxxx>]

If the idle changes when going into park it means the idle control
motor is not fully controlling the idle speed. Check the usual things,
air leaks, air screws open, electrical problem with the idle motor
circuit, etc.  950 RPM's is high. A properly set up and running PRV
can be very steady (with the usual minor hunting of course) at 775 or
even lower. Most of the time people set the idle high because it won't
idle stablely at the proper speed. Instead of fixing the problem they
try to "adjust" it away. It is always easier to "fix" things by
turning some adjustment than doing it right and finding the real
problem. In an automatic having a high idle can cause "creep",
increase trans fluid temperatures, in general making the transmisssion
work harder (and the brakes). The idle speed was a compromise between
emissions, driveability, wear-and-tear on the drivetrain, and fuel
economy. Generally the lower the better. In a manual higher is easier
for "slipping" the clutch into 1st but even there if the motor isn't
idling well at 775 it won't idle much better at 950 and could stall
easier even with a higher idle. 
 The bottom line is 775 is a good idle speed for the PRV in our
Deloreans, the main caveat is that the motor MUST be set up and
running properly to achieve it!
David Teitelbaum
vin 10757


--- In dmcnews@xxxxxxxxxxxxxxx, Farrar Hudkins <fhudkins@...> wrote:
>
> I agree, 950 is good, especially since below there the car shudders. 
> (Although it's relaxing if my back muscles are tense...)
> 
> Segue time! Here's a question for you automatic owners:
> 
> When you're parked and put the car in "Park" prior to turning it off, 
> does the car rev up? Mine does. Not as badly as before, but approaching 
> 1,500rpm when I shift from "Drive" to "Park" -- only after a drive, not 
> when I start it up.
> 
> No big deal, but it is something I've never seen any other car do.
> 
> By the way, I've uploaded some photos to the pic directory "2613" on
the 
> Yahoo Groups site.
> 
> Cheers,
> Farrar Hudkins
> #2613
> 
> John Hervey wrote:
> > 
> > 
> > 950 is where I idle all the DeLoreans I normally work with. Oil
pressure is
> > better, amps from the alternator is better and it's just that much
further
> > out of the hold when you take off from a light.
>




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