RE: RE: Re: Cold Starts causes Check Engine Light + LIMP mode

From: Bernd D. Ratsch (bernd@dodgetrucks.org)
Date: Thu Sep 13 2007 - 09:42:09 EDT


I wouldn't doubt it....you wouldn't believe some of the crap I see even on
these new vehicles (pretty shotty workmanship).

- Bernd

-----Original Message-----
From: WiLieR[SS] [mailto:waffle787@gmail.com]
Sent: Thursday, September 13, 2007 8:21 AM
To: dakota-truck@dakota-truck.net
Subject: Re: DML: RE: Re: Cold Starts causes Check Engine Light + LIMP
mode

When I dug into the wiring harness on my 96 I found the fi splices to
be nothing more than a taped up copper ring that was crimped flat onto
the stripped ends of the wiring for the injectors. There was no
solder at all on them. I removed the rings, cleaned everything with
electrical contact cleaner and then soldered them up with acid-free
solder. Some more tape and things were good again. About a month
later I was having other sensor issues so I did the same for the tps,
map and crank pos sensor voltage feed splices and found the same
crimped on copper rings that had corroded like crazy. Same fix for
them and immediately saw voltage readings from the sensors jump up to
normal. The pcm, which I had forgotten to reset after the fix, saw it
too and threw a bunch of codes. All of the codes basically said
"voltage reading higher than expected from tps, map and crank pos."
Reset the pcm and it was back to smooth cold starts and even better
acceleration. I know it seems odd that corroded wiring would only
affect cold start ups, but that was the case with my 96.

WiLieR

On 9/13/07, Bernd D. Ratsch <bernd@dodgetrucks.org> wrote:
>
> The splices are a solder joint - no connector unless specified in the
wiring
> diagrams. I'll pull down the wiring diagrams for you and email them. You
> can pierce the harness if you really need to, but it's better to back
probe
> the connectors to prevent any possible corrosion from the wire pierce (or
> you can seal it up with RTV). On the injectors - they are ground
switched -
> The ASD relay powers them up and the ground switching is controlled via
the
> PCM.
>
> If the vehicle is running rough on initial start but no problems at normal
> temp...it doesn't sound like a wiring issue (not ruling it out though).
Do
> you have access to a scanner? If you have a DVOM (Digital Volt/Ohm
Meter),
> check the resistance of the coolant temp sensor when cold and when it's at
> normal temp. Let me know what you find.
>
> - Bernd



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