Starting engine cold vs. warm after ECU reset
Thread Starter
Joined: Sep 2004
Posts: 80
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From: Skokie, IL, U.S.
Starting engine cold vs. warm after ECU reset
How would each affect things differently? Personally, I've noticed a difference in the way the engine sounds as its rpm raises in 1st gear.
<U>Definitions</U>
-By starting cold I mean the engine has not been run for 15 or so hours and has been sitting outside in 40-50 degree weather, or equivalent.
-Starting warm would mean having been driven around, fully warmed up, just in the past couple of minutes.
<U>Definitions</U>
-By starting cold I mean the engine has not been run for 15 or so hours and has been sitting outside in 40-50 degree weather, or equivalent.
-Starting warm would mean having been driven around, fully warmed up, just in the past couple of minutes.
Mad Scientist
Joined: Nov 2002
Posts: 5,827
Likes: 1
From: tallafizzy, FL state
Re: (PrettyLude)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PrettyLude »</TD></TR><TR><TD CLASS="quote">it would be better to let it warm up to operating temperatures to ensure oil flow is everywhere throughout the engine</TD></TR></TABLE>
lol, oil goes throughout the engine after a few seconds of starting.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by M1 »</TD></TR><TR><TD CLASS="quote">By this you mean start cold, and let it warm up? Or start warm?</TD></TR></TABLE>
when the engine is cold, oil viscosity is not the same as when in operating temperature, thus not allowing the right lubrication.
the engine run rough when cold cause of not being able to create a nice spark
lol, oil goes throughout the engine after a few seconds of starting.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by M1 »</TD></TR><TR><TD CLASS="quote">By this you mean start cold, and let it warm up? Or start warm?</TD></TR></TABLE>
when the engine is cold, oil viscosity is not the same as when in operating temperature, thus not allowing the right lubrication.
the engine run rough when cold cause of not being able to create a nice spark
Thread Starter
Joined: Sep 2004
Posts: 80
Likes: 0
From: Skokie, IL, U.S.
Re: (mmuller)
When I mentioned the engine sounding differently in the upper half the the rpm range in 1st gear, I mean during subsequent driving after idling for a while following the ecu reset. Both of the times spent driving, the engine was fully warmed up, while one of these driving sessions followed an idling session that started cold.
The difference, thus, is in subsequent performance!
Modified by M1 at 11:46 AM 10/21/2004
The difference, thus, is in subsequent performance!
Modified by M1 at 11:46 AM 10/21/2004
Honda-Tech Member
Joined: Oct 2001
Posts: 4,611
Likes: 3
From: Severn, MD
Re: (M1)
When you reset the ECU, you are resetting fuel trim parameters. My 99 stock hatch typically runs at about +4-5% - this means that the stock ECU fuel maps are a touch lean and so the ECU richens up the mix (by looking at the O2 sensor).
So now, if I reset my ECU, I'll actually run a hair leaner before the ECU re-learns the long term and short term fuel trim values - then things are back the way they were.
So now, if I reset my ECU, I'll actually run a hair leaner before the ECU re-learns the long term and short term fuel trim values - then things are back the way they were.
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