coolant sensor liar (wasTuning 101)

[xxalexx at ix.netcom.com]

> From:          Mike Jones <rmjones at cyberhighway.net>
> To:            "'diy_efi at efi332.eng.ohio-state.edu'"
>                <diy_efi at efi332.eng.ohio-state.edu>
> Subject:       coolant sensor liar (wasTuning 101)
> Date:          Tue, 31 Mar 1998 15:24:16 -0800
> Reply-to:      diy_efi at efi332.eng.ohio-state.edu

> <snip>  Bruce Plecan wrote:
> Just got reminded of something I didn't mention earlier.  No I do not
> stop, and start the car for every change I make.
>   Again depending on the car.  I might make a coolant temp sensor
> liar (adjustable pot in series with sensor), >>>
> 
> 
> 
> Speaking of coolant sensor liar--
> 
> I've been working through a problem with my Powerstroke diesel, which if 
> you're not familiar with the breed, is a direct-injected diesel completely 
> controlled by the PCM, right down to the drive-by-wire throttle.
> 
> The problem is what can only be described as a lean missfire under 
> acceleration when fully warm.  It feels just like a gas engine with a plug 
> wire off.  Done it since new.  No codes are set, and I've heard through a 
> couple of reliable sources that there is no 'defect', the PCM was 
> calibrated this way for California and California wannabe's.  It runs 
> strong as a horse  when partially warm, coolant temp around 120-130 
> degrees.
> 
> Anybody have an idea of what range resistor I should begin experimenting 
> with so as to knock the reported temp down from 160?  This may be a quick 
> and dirty way to get me where I want to go.
> 
> Mike Jones
> 
> 
I have used 10K pot to ground.  Most work shops manuals have a 
themistor curve.
alex