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16v has more power when motor is cold?
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Could be that your tires are just not as grippy when they're cold??
:)
Seriously, I sometimes feel like my 16V pulls a little harder when it's =
cold, too.
Larry
----- Original Message -----=20
From: T. Reed=20
To: scirocco-l@scirocco.org=20
Sent: Thursday, November 21, 2002 7:25 PM
Subject: 16v has more power when motor is cold?
Hey all,
Just got back from a drive tonight and I noticed that during the first =
2
minutes or so the car had kick ass power.. I mean, I was barely laying =
in
to the throttle .. probably just a touch over half way, and the tires =
were
chirping in 1st and 2nd without even trying. After the car was warmed
up I went over the same stretch of road and while it was still fast =
and
there was no "huge" reduction in power, I couldn't get the tires to =
chirp
again with the same amount of throttle. Both times I was just doing my
normal smooth declutching action.
I know that's not very scientific, but I'm feeling like my motor is
running "torquier" when it hasn't warmed up yet. Ambient air temp is =
about
50 F, but I can't imagine that cold vs. warm air could make that much =
of a
difference, besides.. my engine runs cold to begin with (I never get =
to
the LED on the water temp gauge)
I do have my mixture set to 4 mA +/- 1 mA.. Stock is 5 mA or 10 mA
depending on who you ask. This is a 2.0 16v with 1.8 head, BTW.
I've noticed that my idle bounces a bit until the car warms up. I've =
heard
that this can indicate a rich mixture, but I can't rememebr why.
I suspect that what might be happening is while the car is in open =
loop
mode, the mixture is not influenced by the O2 sensor and is going rich
because of my non-stock mechanical setting of the mixture screw. But
once the car warms up, the oxygen sensor bypasses the mechanical =
setting,
leaning out the mixture and causing me to loose power..
I replaced the sensor about 1.5 years ago with a universal bosch =
sensor
and spliced the wires in to the original harness.
So I'm wondering:
- what is the difference between euro mechanical CIS for 16v's and our
CIS-E running in open loop mode? It seems to me like there should be =
no
difference.. in steady-state conditions the mixture is based =
completely
off of the mechanical adjust screw when in open loop mode.. it =
should
be possible to force the car in to open loop (by disconnecting the =
o2
sensor) and tune the screw to keep something just a little richer =
than
stoich. This would also preserve all the warm-up and acceleration
enrichment features of CIS-E (assuming they normally operate when in
open loop)
- has anyone tried placing a resistor in line with the oxygen sensor =
to
cause its output voltage to be divided between the resistor and the
computer, effectively making the computer "see" a lower voltage =
(which
corresponds to a leaner mixture) and thus causing it to richen the
mixture on its own? It seems like this would work.. if it did then =
you
could put a potentiometer in line and tune the mixture to your =
liking,
electrically.
I think I might try the latter, and borrow my friend's homemade air =
fuel
meter that hooks to the o2 sensor and see if putting resistance inline
is indeed effective in changing the mixture. First, though.. I'll need =
to
put an ammeter inline with the o2 sensor and see how much current is =
going
through the circuit so I can determine what range of resistance is =
needed.
Anyway, I just thought I'd share my ideas about this since I know =
CIS-E is
notorious for leaning things out in the name of fuel economy.
I've thought about buying one of those euro CIS setups for $300-ish =
but in
my opinion there is nothing mechanically wrong with the CIS-E I =
already
have.. its more than capable of delivering the amount of fuel (and the
proper amount, at that).. so why junk it? As an electrical engineering
student I'm inclined to find an electrical (read: cheap; components =
cost
just pennies and are readily available) solution that uses the =
existing
mechanical parts and sensors to accomplish the same goal.
-Toby
_______________________________________________
Scirocco-l mailing list
Scirocco-l@scirocco.org
http://neubayern.net/mailman/listinfo/scirocco-l
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<DIV><FONT face=3DArial size=3D2>Could be that your tires are just not =
as grippy=20
when they're cold??</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>:)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2>Seriously, I sometimes feel like my 16V =
pulls a=20
little harder when it's cold, too.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT face=3DArial size=3D2>Larry</FONT></DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: =
0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A href=3D"mailto:treed2@u.washington.edu"; =
title=3Dtreed2@u.washington.edu>T.=20
Reed</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A=20
href=3D"mailto:scirocco-l@scirocco.org"=20
title=3Dscirocco-l@scirocco.org>scirocco-l@scirocco.org</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Thursday, November 21, =
2002 7:25=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> 16v has more power =
when motor is=20
cold?</DIV>
<DIV><BR></DIV>Hey all,<BR><BR>Just got back from a drive tonight and =
I=20
noticed that during the first 2<BR>minutes or so the car had kick ass =
power..=20
I mean, I was barely laying in<BR>to the throttle .. probably just a =
touch=20
over half way, and the tires were<BR>chirping in 1st and 2nd without =
even=20
trying. After the car was warmed<BR>up I went over the same stretch of =
road=20
and while it was still fast and<BR>there was no "huge" reduction in =
power, I=20
couldn't get the tires to chirp<BR>again with the same amount of =
throttle.=20
Both times I was just doing my<BR>normal smooth declutching =
action.<BR><BR>I=20
know that's not very scientific, but I'm feeling like my motor =
is<BR>running=20
"torquier" when it hasn't warmed up yet. Ambient air temp is =
about<BR>50 F,=20
but I can't imagine that cold vs. warm air could make that much of=20
a<BR>difference, besides.. my engine runs cold to begin with (I never =
get=20
to<BR>the LED on the water temp gauge)<BR><BR>I do have my mixture set =
to 4 mA=20
+/- 1 mA.. Stock is 5 mA or 10 mA<BR>depending on who you ask. This is =
a 2.0=20
16v with 1.8 head, BTW.<BR><BR>I've noticed that my idle bounces a bit =
until=20
the car warms up. I've heard<BR>that this can indicate a rich mixture, =
but I=20
can't rememebr why.<BR><BR>I suspect that what might be happening is =
while the=20
car is in open loop<BR>mode, the mixture is not influenced by the O2 =
sensor=20
and is going rich<BR>because of my non-stock mechanical setting of the =
mixture=20
screw. But<BR>once the car warms up, the oxygen sensor bypasses the =
mechanical=20
setting,<BR>leaning out the mixture and causing me to loose =
power..<BR><BR>I=20
replaced the sensor about 1.5 years ago with a universal bosch =
sensor<BR>and=20
spliced the wires in to the original harness.<BR><BR>So I'm=20
wondering:<BR><BR>- what is the difference between euro mechanical CIS =
for=20
16v's and our<BR> CIS-E running in open loop mode? It seems to =
me like=20
there should be no<BR> difference.. in steady-state conditions =
the=20
mixture is based completely<BR> off of the mechanical adjust =
screw when=20
in open loop mode.. it should<BR> be possible to force the car =
in to=20
open loop (by disconnecting the o2<BR> sensor) and tune the =
screw to=20
keep something just a little richer than<BR> stoich. This would =
also=20
preserve all the warm-up and acceleration<BR> enrichment =
features of=20
CIS-E (assuming they normally operate when in<BR> open =
loop)<BR><BR>-=20
has anyone tried placing a resistor in line with the oxygen sensor=20
to<BR> cause its output voltage to be divided between the =
resistor and=20
the<BR> computer, effectively making the computer "see" a lower =
voltage=20
(which<BR> corresponds to a leaner mixture) and thus causing it =
to=20
richen the<BR> mixture on its own? It seems like this would =
work.. if it=20
did then you<BR> could put a potentiometer in line and tune the =
mixture=20
to your liking,<BR> electrically.<BR><BR>I think I might try the =
latter,=20
and borrow my friend's homemade air fuel<BR>meter that hooks to the o2 =
sensor=20
and see if putting resistance inline<BR>is indeed effective in =
changing the=20
mixture. First, though.. I'll need to<BR>put an ammeter inline with =
the o2=20
sensor and see how much current is going<BR>through the circuit so I =
can=20
determine what range of resistance is needed.<BR><BR>Anyway, I just =
thought=20
I'd share my ideas about this since I know CIS-E is<BR>notorious for =
leaning=20
things out in the name of fuel economy.<BR><BR>I've thought about =
buying one=20
of those euro CIS setups for $300-ish but in<BR>my opinion there is =
nothing=20
mechanically wrong with the CIS-E I already<BR>have.. its more than =
capable of=20
delivering the amount of fuel (and the<BR>proper amount, at that).. so =
why=20
junk it? As an electrical engineering<BR>student I'm inclined to find =
an=20
electrical (read: cheap; components cost<BR>just pennies and are =
readily=20
available) solution that uses the existing<BR>mechanical parts and =
sensors to=20
accomplish the same=20
=
goal.<BR><BR>-Toby<BR><BR><BR>___________________________________________=
____<BR>Scirocco-l=20
mailing list<BR><A=20
=
href=3D"mailto:Scirocco-l@scirocco.org";>Scirocco-l@scirocco.org</A><BR><A=
=20
=
href=3D"http://neubayern.net/mailman/listinfo/scirocco-l";>http://neubayer=
n.net/mailman/listinfo/scirocco-l</A><BR></BLOCKQUOTE></BODY></HTML>
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