Benching Ecms

[Bruce Plecan]

-----Original Message-----
From: T Hergen <thergen at svn.net>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Wednesday, July 29, 1998 7:59 PM
Subject: Re: Benching Ecms


>Bruce,
>
>How do you have it wired up?  Something like the following
>(used fixed width font to view)?:
>
>  +5 ___
>        |
>        |
>        \
>        /<---- to ecm map input
>        \
>    5k  /
>        \
>        /
>        |
>  gnd___|
>
>Are the limiting resistors you mention wired in series with
>gnd or +5 supplies?  Putting them inline with the connnection
>to the ecm probably won't give the desired result.

Well that's exactly what I did (in series with the ecm input lead).
Thanks
Bruce


>
>If there's a pullup or pulldown (or maybe even to some intermediate
>voltage) in the ecm, this may cause some voltage other than what you
>expected.  Using a 1k or lower pot (instead of 5k) may get the resulting
>voltage closer to what you expect.
>
>No, I haven't tried this myself.
>
>Tom
>
>On Wed, 29 Jul 1998, Bruce Plecan wrote:
>
>> Finally applied power to the bench ecm project today, and all seems
>> good and well so far.  Upon reflection I want to run something past the
>> folks that have already done this, is using a 5K pot OK for the MAP,
>> and TPS??..
>>     The reason I ask is that with the MAP twisted to high and with a
>> 1K ohm resistor in line, I still get a MAP voltage of 5.1volts.  Should I
>> increase the value of the "limiting" resistor?.
>>     I also used a 470 ohm resistor thinking that would keep the min
>> TPS to about .5volts, but it's .18volts.
>>     What's the error in my thinking here.
>> TIA
>> Bruce          Ya shoulda seen the staff run when I yelled "Fire in the
>>                     Hole", when I flipped the main switch on.
>>
>
>