It's just like turning on a computer... there is a POST (power on self
test)
that occurs... The PCM checks sensors for baseline readings (paying
particular attention to barometric pressure, intake air temp and either
engine coolant temp or engine oil temp- comparing these to "look up"
tables
to determine starting strategy) and may "sweep" some or all of the PCM
controlled actuators. Well known is that the fuel pump runs briefly to
bring
the fuel rail to pressure, but the PCM may cycle other actuators that are
monitored to determine circuit integrity.
Even with the baud rates we had in the early 90s, there isn't really any
need to wait more than a second or two to ensure that the POST completes.
If you have the chance, open the hood and have an assistant turn the key
to
the run position... you are sure to here at least a few little clicks and
clacks as the PCM performs it's duties.
"Ulysses" <eatmyspam@[EMAIL PROTECTED]
> wrote in message
news:n0HVj.53625$kl6.39560@[EMAIL PROTECTED]
>
> "CWLee" <cdubyalee@[EMAIL PROTECTED]
> wrote in message
> news:25lVj.35$z4.8914@[EMAIL PROTECTED]
>>
>> I'd like to know both the conventional wisdom about, and the
>> common practices you guys use, starting your Explorer after
>> it has been sitting outside all night in 40-60 degree temps.
>>
>> Some of my friends start it and drive away immediately.
>> Another buddy lets it idle for 5 full minutes before moving.
>> I have tended to wait until I detected a slight uptick in
>> the temp gauge needle, but sometimes I'm in a hurry and only
>> wait 30-60 seconds.
>>
>> Everything I've read on the topic is non-quantitative,
>> meaning the wording is "briefly" or "for a little while"
>> etc.
>>
>> Thanks.
>>
>> --
>> ----------
>> CWLee
>> Former slayer of dragons; practice now limited to sacred
>> cows. Believing we should hire for quality, not quotas, and
>> promote for performance, not preferences.
>>
>
> First I turn on the ignition and let it set until it stops beeping.
Then
> I
> start it up and let my car idle until the idle speed drops to normal
which
> takes about 10-15 seconds usually.
>
> I don't know if it's true or not but I've heard that when you first turn
> on
> the ignition ('91 Explorer) the computer is checking all the sensors and
> deciding how much air/fuel and all to give it depending upon how cold it
> is
> and all.. In any case it probably can't hurt to wait 7 or 8 seconds
> before
> starting it.
>
> I also don't change direction while moving. If I back up I wait until
the
> car is completely stopped before ****fting into D. Again, I don't know
if
> this really does any good...
>
>
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