coolant sensor liar (wasTuning 101)

[Bruce Plecan]

-----Original Message-----
From: Mike Jones <rmjones at cyberhighway.net>
To: 'diy_efi at efi332.eng.ohio-state.edu' <diy_efi at efi332.eng.ohio-state.edu>
Date: Tuesday, March 31, 1998 6:27 PM
Subject: coolant sensor liar (wasTuning 101)


><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
>
Make sure that there are no other temperature dependent items..
On a GM neg temp coeff., I use 5K.  If your looking for 12ish
1K might work.

No worries Mate
Bruce