Re: RE: Cold-Start Hesitation - Finally Fixed

From: Gary Hedlin (ghedlin@theramp.net)
Date: Sun May 25 2003 - 13:33:44 EDT


Thanks bernd!!

If only you could find a way to make about 100,000 miles dissaper from my
truck!! :)

--
Gary Hedlin
President
Hedlin Web Designs
http://www.hedlin.net
""Bernd D. Ratsch"" <bernd@texas.net> wrote in message
news:000001c322e7$0197c820$090aa8c0@homenet.com...
>
> One thing I forgot to point out:
>
> On initial startup (and even after a cool-down period), the engine will
> run a little bit rough due to the warm-up cycle on the O2 sensor(s).
> This is normal (takes about 2-3 minutes max)...the lean-out "pop" was
> not.
>
> - Bernd
>
> -----Original Message-----
> From: owner-dakota-truck@bent.twistedbits.net
> [mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of Bernd D.
> Ratsch
> Sent: Sunday, May 25, 2003 11:49 AM
> To: dakota-truck@dakota-truck.net
> Subject: DML: Cold-Start Hesitation - Finally Fixed
>
>
> After going through a lot of different options and tests, I finally
> found the cold-start (rough running) problem on the truck.
>
> I know a few others have had this same problem and it could also be a
> fix for you...but you'll need to check first.
>
> Problem:
> On initial (early AM startup), the engine runs rather rough (like it's
> got some sort of huge cam in it) and back-fires through the intake. Went
> through TPS, MAP, O2, IAT, and a few other options as well (including
> fuel sync and distributor alignment).  Everything checked out fine and
> well within spec.
>
> Solution:
> Coolant Temp Sensor was off by 4K ohm (lower than normal) causing a
> leanout condition.  Remember, the CTS also works like the old chokes on
> carbureted engines (engine warm-up).  Early AM CTS resistance should be
> about 9.4-9.8K ohm for my area (74-78 degrees F).  Sensor was at 5.7K
> ohm...this equates to 104 degrees at cold-start (not good).  PCM thought
> engine was warmer than actual temp and was leaning out the fuel a little
> early.
>
> No more backfire or lean-out condition.
>
> - Bernd
>
>
>
>



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