DIY_EFI Digest           Tuesday, 12 November 1996     Volume 01 : Number 343

In this issue:

	RE: O2 Sensor Open/Close Loop
	RE: O2 Sensor Open/Close Loop
	Re: Bosch 4&3wire sensor
	Re: Bosch 4&3wire sensor
	Re: O2 Sensor Open/Close Loop
	Re: Need help with Mazda EFI.
	Re: What is the story with Synth-Oil
	Re: O2 Sensor Open/Close Loop
	Re: O2 Sensor Open/Close Loop
	late 95+ ECU performance (on turbo Talon & Eclipse)
	Air Fuel Ratio/ Lambda
	Re: Air Fuel Ratio/ Lambda
	Re: Hi Looking for information Prom Burners
	drivers and sensors
	RE: O2 Sensor Open/Close Loop
	re: late 95+ ECU performance (on turbo Talon & Eclipse)
	Re: drivers and sensors
	re: O2 Sensor Open/Close Loop
	re: 2 Stroke Injection
	Re: drivers and sensors

See the end of the digest for information on subscribing to the 
DIY_EFI or DIY_EFI-Digest mailing lists.

----------------------------------------------------------------------

From: "Gregory Chan" <gchan@xxx.ca>
Date: Mon, 11 Nov 1996 08:06:52 EDT
Subject: RE: O2 Sensor Open/Close Loop

> >
> >begin 600 WINMAIL.DAT
> >M>)\^(AX3`0:0" `$```````!``$``0>0!@`(````Y 0```````#H``$(@ <`
> >M& ```$E032Y-:6-R;W-O9G0@xxx.;W1E`#$(`0V ! `"`````@`"``$$
> 
> Ya' know, I've never figgered out what this encoded message
> stuff is all about -- is some neat porno stuff I'm missing??
> 
> Wazzitmean??
> 
> 
> Tom ,
            That stuff is an encoded message by the Windows95 mailer. 
It can be un-encoded by Pegasus mail or any other mailing program
which supports uudecode.

gchan@xxx.ca
> 
> 

------------------------------

From: Anthony Tsakiris <atsakiri@xxx.com>
Date: Mon, 11 Nov 1996 08:35:53 -0500
Subject: RE: O2 Sensor Open/Close Loop

Doh!  Sorry about all the garbage.  I hate that
stuff.  I just started using new mail software
and I guess I haven't got it all figured out yet.

If anyone out there know how to configure MS
Exchange so that it will produce simple ASCII
text messages, please e-mail (atsakiri@xxx.com)
with the secrets.  How I miss regular ol' mail.

A. Tsakiris


- ----------
From: 	tom cloud
Sent: 	Friday, November 08, 1996 4:00 PM
To: 	diy_efi@xxx.edu
Subject: 	RE: O2 Sensor Open/Close Loop

>
>Probably "TWC" means "three way catalyst."
>
>
>A. Tsakiris
>
>begin 600 WINMAIL.DAT
>M>)\^(AX3`0:0" `$```````!``$``0>0!@`(````Y 0```````#H``$(@ <`
>M& ```$E032Y-:6-R;W-O9G0@xxx.;W1E`#$(`0V ! `"`````@`"``$$

Ya' know, I've never figgered out what this encoded message
stuff is all about -- is some neat porno stuff I'm missing??

Wazzitmean??


Tom Cloud <cloud@xxx.edu>


begin 600 WINMAIL.DAT
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MD 8`9 $```$````,`````P``, (````+``\.``````(!_P\!````8P``````
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`
end

------------------------------

From: cloud@xxx.edu (tom cloud)
Date: Mon, 11 Nov 1996 08:09:46 -0600
Subject: Re: Bosch 4&3wire sensor

>tom cloud wrote:
>> 
>> >Hi in a 4 wire O2 sensor you have sensor gnd, earth, heater =ve, and
>> >signal
>> >in a 3 wire heated is it common ground, and there fore will it upset my
>> >autronic SMC if i use the chassis ground effectively for both for this
>> >function. if i then conect sensor ground to chassis will this upset
>> >things????
>> >
>> >have plenty of 3 wire ones free, 4 wire ones 350 dollars
>> 
>> 4-wire sensor used on '91 F-150.  ~ $90 from Ford.  Found it
>> available on net for ~ $50.  I'll get name if you want it.
>> 
>> Tom Cloud <cloud@xxx.edu>
>
>
>
>please
>please
>please
>
>
>
>-- 
>|===============================================================|
>|			When I die, 				|
>|         I want to go in my sleep, like my grandfather, 	|
>|          not screaming like the passengers in his car. 	|	
>|---------------------------------------------------------------|
>|  	Doug Robson     	   mailto:doug@xxx.au	|
>|				mailto:Doug.Robson@xxx.com	|
>|    Sydney, Australia		 http://www.cia.com.au/doug	|
>|---------------------------------------------------------------|
>|    Club Car Racing Register of NSW	    |	Thank God	|
>|  1992/93 Under 2 litre State Champion	    |	   for		|
>| http://www.cia.com.au/doug/ccrrnsw.html   |	Gravity		|
>|===============================================================|


..................................................

Date: Wed, 31 Jul 1996 17:44:03 -0400
From: Partlink@xxx.com
To: cloud@xxx.edu
Subject: Re: catalog - quote


Part #1060  $38.01

This is our 4 wire oxygen sensor.  You can e-mail your order or call at
1-800-347-2702.  We charge $5.00 S/H on orders under $100.00 and we pay the
freight for orders above $100.00.  We except Visa/Mastercard/COD/or check in
advance.
Any questions or concerns let us know!

Thanks!

..................................................

Date: Mon, 7 Oct 1996 11:12:16 -0400
From: Partlink@xxx.com
To: cloud@xxx.edu (tomcloud)
Subject: Oxygen Sensors

The oxygen sensor (part # 1060) is manufactured by NGK which also supplies
that oxygen sensor to the Original Equipment dealers so this sensor should be
the replacement.


Tom Cloud <cloud@xxx.edu>

------------------------------

From: cloud@xxx.edu (tom cloud)
Date: Mon, 11 Nov 1996 08:12:01 -0600
Subject: Re: Bosch 4&3wire sensor

>tom cloud wrote:
>> 
>> >Hi in a 4 wire O2 sensor you have sensor gnd, earth, heater =ve, and
>> >signal
>> >in a 3 wire heated is it common ground, and there fore will it upset my
>> >autronic SMC if i use the chassis ground effectively for both for this
>> >function. if i then conect sensor ground to chassis will this upset
>> >things????
>> >
>> >have plenty of 3 wire ones free, 4 wire ones 350 dollars
>> 
>> 4-wire sensor used on '91 F-150.  ~ $90 from Ford.  Found it
>> available on net for ~ $50.  I'll get name if you want it.
>> 
>> Tom Cloud <cloud@xxx.edu>
>
>
>
>please
>please
>please
>
>
>
>-- 
>|===============================================================|
>|			When I die, 				|
>|         I want to go in my sleep, like my grandfather, 	|
>|          not screaming like the passengers in his car. 	|	
>|---------------------------------------------------------------|
>|  	Doug Robson     	   mailto:doug@xxx.au	|


Okay, Doug ..... I already sent this last week -- now you owe me:

I want an explanation of your sig .... Is it a joke?  What's the
story?

Tom

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,


..................................................

Date: Wed, 31 Jul 1996 17:44:03 -0400
From: Partlink@xxx.com
To: cloud@xxx.edu
Subject: Re: catalog - quote


Part #1060  $38.01

This is our 4 wire oxygen sensor.  You can e-mail your order or call at
1-800-347-2702.  We charge $5.00 S/H on orders under $100.00 and we pay the
freight for orders above $100.00.  We except Visa/Mastercard/COD/or check in
advance.
Any questions or concerns let us know!

Thanks!

..................................................

Date: Mon, 7 Oct 1996 11:12:16 -0400
From: Partlink@xxx.com
To: cloud@xxx.edu (tomcloud)
Subject: Oxygen Sensors

The oxygen sensor (part # 1060) is manufactured by NGK which also supplies
that oxygen sensor to the Original Equipment dealers so this sensor should be
the replacement.


Tom Cloud <cloud@xxx.edu>

------------------------------

From: cloud@xxx.edu (tom cloud)
Date: Mon, 11 Nov 1996 08:47:46 -0600
Subject: Re: O2 Sensor Open/Close Loop

>tom cloud wrote:
>> 
>> I don't know for sure, but some calculation has to be made (is
>> it basically in speed-density mode ??? at WOT ???)  Clearly, if
>> it's already speed-density, then it just goes with whatever calcs
>> or maps are set up for it.  
>
>What do the OEM guys use to setup the map values for pulse vs RPM vs
>temp vs load?
>
>
>Mark Mason

Mark,  I'll tell you what I know (very little):  To my way of thinking,
EFI is a sophisiticated extension of carburation.

Gots an engine.  Need air + fuel.  Assume the basic engine design is ok.

Carb gives A/F mixture based on venture principle for mid to WOT and
on atmospheric pressure / manifold pressure for idle (I welcome
corrections here).  The "calculations" are effective and have worked
for years, but they cannot be precise -- it's a mechanical kluge that
becomes far too complex trying to integrate all the engine variables
(temp, load, atmos pressure, altitude, humidity, etc) that affect
engine operation.

Carb has idle 'circuit', cold operation 'circuit' (choke), normal /
cruise 'circuit' (venturi), and acceleration / power 'circuit' (accel.
pump).

The Holley EFI I have duplicates these 'circuits' effectively -- better
than a carb -- using only engine rpm, temp, and TPS -- with the option
to add EGO feedback.

OEM EFI, IMHO, just fine tunes these functions.  I believe that we
hinder ourselves, many times, trying to duplicate their systems, which
are designed to meet EPA standards, and are created with massive research
budgets.

Duplicate a carb and your vehicle will run -- well.  Fine tune the
functions and it _might_ run better.  Fine tune it a little more, spend
an inordinate amount of time and money and achieve, maybe, some
questionable improvements (point of diminishing returns).  Add spark
control, data logging, etc.  All of these are probably fun.  What's
needed?  Whatta 'u want?  Power?  Nah!  Economy?  Legal?

Use EGO feedback, and you can reduce emissions.  Oscillate the EGO
output and you can use a three-way catalyst.  Run a little lean, increase
emissions and improve economy.  Run a little rich, increase emissions
and improve performance.  Unfortunately, the EGO is only accurate at
stoich (A:F = 14.7:1), so it is not an effective feedback for other fuel
mixtures.  For those, you're stuck with educated 'guesses'.  (I'd like
to build a system that stores parameters at various engine operating
conditions -- at stoich -- and extrapolates 'intelligently' to desired
leaner or richer mixtures.)

I 'spect the OEM guys do lots of testing to get the "mixture" (it's
a pun, get it?) just right.  That's why I like the little pots on
my EFI.  I can fine tune it rat now!  Don't need no $2000 laptop.
What do I think I want?  It'd be re-programmable via laptop,
but it would have 'analog' potentiometer-type controls to allow
fine tuning -- maybe even 'coarse' tuning.  Could then read selected
values from laptop and make program changes.  I also plan to use the
best of both analog and digital -- including external circuitry --
to simplify the design and programming process.  Avoid doing every-
thing with the processor.  For example, set the injector pulse width
buy loading a timer that's triggered from ignition pulse and then
leave it alone 'til it needs changing.  If doing ignition, do the
same thing with spark advance.  This frees up the processor (and,
more importantly, makes my programming chores easier -- don't have
to worry about tight interrupt loops, etc) to do things like figger
out what the injection p.w. needs to be.  Dunno, it's a bag-'a-
worms -- there are many factors.  That's why I have to kick my
cranial mass back to considering the simplicity of my Holley
Pro-Jection:  only uses rmp, TPS, and temp (for 'choke' function),
and it works great!  I would expect it to work with less adjustment for
atmospheric and altitude (same thing) changes if I added EGO
feedback.

Now, where are youse guys on this list that really know about this stuff?


Tom Cloud <cloud@xxx.edu>

------------------------------

From: cloud@xxx.edu (tom cloud)
Date: Mon, 11 Nov 1996 08:56:52 -0600
Subject: Re: Need help with Mazda EFI.

>At 07:06 PM 11/7/96 -0800, you wrote:
>>Fouled/flooded plugs may not fire a timing light.
>>Either change them or try setting a plug(still connected) on the engine and 
>>watch for spark.
>> 
>>
>>>Yeah, I strapped the timing light onto each of the three coils to check for
>>>spark and didn't get any on any of the coils.  All of the switching
>>>transistors for firing the injectors are run by T304 on the board (that
>>>Toshiba Japan IC I asked about), and I checked the transistors last night
>>>(sort of) and it appears that they are ok.  That pretty much only leaves the
>>>IC that drives them.
>
>I had a similar problem on my 88 Mustang GT.  I have Accel 8.8 Spiral Race
>Wires (junk very high resistance and will be replaced in the spring) 
>My timing light did not work and i borrowed a wire off a buddy's Chev 305,
>and voila, timing light worked perfectly.  I thought it was the light, so i
>bought another one...same prob, now i have 2 good lights, and still bad wires.

Be aware that noise reducing plug wires usually are high resistance
when measured with an ohmmeter.  The resistance will have no effect
on firing your plugs (after all E = I * R, so there'll be no voltage
drop until current starts to flow).  It will reduce the current spike
and therefore the noise.  There is no doubt in my mind that old
fashioned WIRE with high voltage insulation will work better, and
if I were a racer, that's what I'd use (I don't think listening to
the AM radio or CD is important in that environment).  But, if you
don't want everyone near you to be irritated 'cause there stereo starts
popping when you're around, use noise suppression wires.

(I'm not saying your wires aren't bad -- only that all noise suppression
wires have higher R than straight wire.)


Tom Cloud <cloud@xxx.edu>

------------------------------

From: "Dan J. Declerck" <declrckd@xxx.com>
Date: Mon, 11 Nov 1996 09:04:48 -0600
Subject: Re: What is the story with Synth-Oil

On Nov 10, 10:40pm, Dimos Katsis wrote:
> Subject: What is the story with Synth-Oil
> I am interested in any opinions on the pros and cons of using synthetic
> oil instead of regular crude. I know that this is not the Car-Talk radio
> show but it would be interesting to see what fellow engineers think.
>
> Thanks
> Dimos K.
>
>-- End of excerpt from Dimos Katsis

This is way off the subject, but:

I use synthetics in severe service conditions. During winter, I run Mobil 1
10w30 in my 5.0L Ford Engine. It makes the car MUCH easier to start when the
temp drops below zero.

I also use synthetics in motorcycles, since the engine and transmission
use the same oil. Mobil 1 lasts twice as long as the organic equivalents.
My Kawasaki Ninja can take organic oil and turn it into something similar to
water in less than 1000 miles. Synthetics usually last 2K miles.

- -Dan

- -- 
=> Dan DeClerck                        | EMAIL: declrckd@xxx.com      <=
=> Motorola Cellular CSD               |                                  <=
=>"The truth to CDMA... is spreading"  | Phone: (847) 632-4596            <=
- ----------------------------------------------------------------------------

------------------------------

From: kleenair@xxx.com
Date: Mon, 11 Nov 1996 11:06:20 -0800
Subject: Re: O2 Sensor Open/Close Loop

tom cloud wrote:
> 


Hi,

This is some more info about open/closed loop and A/F ratio:

The target A/F ratio during WOT can varry from engine to engine.  More specifically, 
it is related to fuel pressure, fuel injector nozzle design, and injector location.  
The objective is to deliver the correct amount of fuel in fine particles to the 
combustion chamber.  So theoredically, if all the fuel was vaporized, you would not 
need a WOT enrichment.  Therefore, on multi port fuel injection systems with higher 
pressures, the WOT A/F is very close to stoichiometric.  In fact, some newer vehicles 
(1996) do not go to open loop during WOT!  By contrast, when you consider a throttle 
body injection setup (or a carburetor), the fuel has many opportunities to form as 
dropplets on intake manifold walls.  Therefore, you add the extra fuel to compensate.
So to make a long story short, depending on your fuel system, both the target A/F, 
and the Open/ closed threshold varry.

Mazda Ebrahimi

------------------------------

From: cloud@xxx.edu (tom cloud)
Date: Mon, 11 Nov 1996 12:44:04 -0600
Subject: Re: O2 Sensor Open/Close Loop

>This is some more info about open/closed loop and A/F ratio:
>

        [ snippeth ]

>The objective is to deliver the correct amount of fuel in fine particles to
the 
>combustion chamber.  So theoredically, if all the fuel was vaporized, you
would not 
>need a WOT enrichment.

Not unless you wanna go FAST.  Max power is obtained richer than
stoich.  If you insist on minimum emissions at all conditions, then
stoich it is!


Tom Cloud <cloud@xxx.edu>

------------------------------

From: Scott Ritter <sritter@xxx.com>
Date: Mon, 11 Nov 1996 14:59:34 -0500
Subject: late 95+ ECU performance (on turbo Talon & Eclipse)

Hi. I've just joined the list and am currently trying to debug a performance 
problem that likely resides in the ECU's of late 95+ turbo Talons & Eclipses. 
Apparently, early 95's, which sport a visibly different ECU board (=> 
different ECU code?), don't have the problem. The problem is that when the 
boost pressure is raised by as little as 1psi above factory nominal, the 
engine suffers from an abrupt power loss due to major timing retard. The 
problem is not consistent at any specific boost level, though; and the timing 
re-advances about a second after the throttle (boost) is reduced.

I've been hypothesizing what might be the (changed) ECU logic behind this 
symptom & some potential hardware work-arounds, and have come up with the 
following list. Any feedback or additional input would be greatly appreciated! 
(I've sent a copy to the Talon Digest already.)

a) MAS air flow/RPM, (computed boost).
Perhaps the new logic includes a test for boost above 12-ish PSI & retards 
timing as the response (prior to the full thrash of fuel cut, at a still 
threshold). If this is the case, then an FCD (commercially available unit to 
limit the airflow sensed) might help some, but the lean fuel condition would 
probably make it too dangerous a fix. This situation is the worst case, since 
the only real "cure" is to change the actual ECU code.

b) Rich exhaust from the post-cat O2 sensor.
I'm going out on a limb here, please excuse the ignorance-factor... Assuming 
that the 2nd O2 sensor is in place to let the ECU know that the cat's doing 
its job, and that going WOT removes careful stoich control on the mixture, 
then
the engine's gonna tend rich (like in the 1st gen's) to handle the big air 
coming in. The high volume of rich exhaust will cause an apparent degradation 
in cat performance, which the ECU will detect. *If* the ECU reacts to reduce 
emissions at this point by reducing timing(?), then there's the problem! If 
this is the case, then putting an ECU-appeasing voltage gain & level-shift 
circuit between the pre-cat O2 sensor output and where the post-cat O2 sensor 
used to be ;-) should eliminate the effect. A software fix would still be the 
cleaner solution, but until that's available, this might be a viable & 
affordable solution.

Question: Would simply pulling the post-cat O2 sensor from the exhaust stream 
(but leaving it attached to the ECU) be likely to confirm/disprove this theory?

c) Pinging
If the ECU's ping-level tolerance has decreased, then we might simulate 
reduced pinging. We could insert a divide-by circuit between the knock sensor 
& the ECU to reduce the number of pings sensed by a jumper-programmable 
factor. Again, there's nothing like a nice software fix, but a divide-by 
circuit should solve this one.

Thanks,
/Scott Ritter
- --------
"In the beginning was the thing. Then one thing led to another." T.R.

------------------------------

From: Doug Robson <doug@xxx.au>
Date: Tue, 12 Nov 1996 08:16:01 +1100
Subject: Air Fuel Ratio/ Lambda

Is the constant between Lamdba and air fuel 14.57 ( australian stoich
number )

eg air fuel/ 14.57 = lambda or is it more difficult than this


- -- 
|===============================================================|
|			When I die, 				|
|         I want to go in my sleep, like my grandfather, 	|
|          not screaming like the passengers in his car. 	|	
|---------------------------------------------------------------|
|  	Doug Robson     (H)	   mailto:doug@xxx.au	|
|			(W)	   mailto:Doug.Robson@xxx.com	|
|    Sydney, Australia		 http://www.cia.com.au/doug	|
|---------------------------------------------------------------|
|    Club Car Racing Register of NSW	    |	Thank God	|
|  1992/93 Under 2 litre State Champion	    |	   for		|
| http://www.cia.com.au/doug/ccrrnsw.html   |	Gravity		|
|===============================================================|

------------------------------

From: cloud@xxx.edu (tom cloud)
Date: Mon, 11 Nov 1996 16:46:45 -0600
Subject: Re: Air Fuel Ratio/ Lambda

>Is the constant between Lamdba and air fuel 14.57 ( australian stoich
>number )
>
>eg air fuel/ 14.57 = lambda or is it more difficult than this

I thought it was ~14.7:1 = A:F = lambda.


Tom Cloud <cloud@xxx.edu>

------------------------------

From: "George M. Dailey" <gmd@xxx.com>
Date: Mon, 11 Nov 1996 18:16:53 -0600 (CST)
Subject: Re: Hi Looking for information Prom Burners

Is there a reason why you are not using an OEM TPI ECM?
GMD

At 04:09 PM 11/9/96 -0800, you wrote:
>Hi 
>My name is George And im wondering if there is anyone out there
>Knows what prom burner is used for the GM sfi injection computer
>fron the 2.8 v6 gm motors. (computer pn#1227730)
>Working with this computer for my small block 350 tpi conversion
>Thanks
>-- 
>George KG2DB
>
>

------------------------------

From: "S. Lastuka" <kicker@xxx.edu>
Date: Mon, 11 Nov 1996 16:40:33 -0800 (PST)
Subject: drivers and sensors

I am a student at the University of Washington and I am on a team 
designing a fuel injection system for a Formula SAE car.  We are currently
programming a 68hc11 and are looking into buying the other components that
will be needed for our system.  We are trying to find a place that sells
injector drivers (peak and hold).  We have heard that Cherry Electronics
sells these drivers but we are having some trouble getting a phone number
for Cherry.  If anyone knows of a place that sells drivers we would
appreciate some information ie phone number, price, address.  Thank you, 

Sean Lastuka   

------------------------------

From: dave.williams@xxx.us (Dave Williams)
Date: Mon, 11 Nov 1996 10:32:00 +0000
Subject: RE: O2 Sensor Open/Close Loop

- -> That stuff is an encoded message by the Windows95 mailer.
- -> It can be un-encoded by Pegasus mail or any other mailing program
- -> which supports uudecode.

 I'm sure all the Windows 95 mailer and Pegasus people are thrilled to
death with their Captain Marvel uuencoder tools.  Perhaps they can
amuse each other over in alt.binaries.misc or something.
                                                                               

------------------------------

From: RABBITT_Andrew@xxx.au
Date: Tue, 12 Nov 1996 08:56:02 est
Subject: re: late 95+ ECU performance (on turbo Talon & Eclipse)

>Apparently, early 95's, which sport a visibly different ECU board (=> 
>different ECU code?), don't have the problem. 

the new ECU is probably more powerful to cope with OBDII requirements

>The problem is that when the boost pressure is raised by as little as 
>1psi above factory nominal, the engine suffers from an abrupt power 
>loss due to major timing retard.

probably a strategy to protect itself from an overboost condition.  
It's obviously not been calibrated at that level of boost, therefore 
destruction by knock is a real possibility, hence the 'major timing 
retard'

>Assuming that the 2nd O2 sensor is in place to let the ECU know that 
the cat's doing its job,

correct!

>and that going WOT removes careful stoich control on the mixture, 
>then the engine's gonna tend rich (like in the 1st gen's) to handle 
>the big air coming in. The high volume of rich exhaust will cause an 
>apparent degradation in cat performance, which the ECU will detect.

I would guess that at WOT, the controller goes open loop and therefore 
ignores the signals from both oxygen sensors.  You can only detect 
catalyst performance with two oxygen sensors working together, and 
then only closed-loop and stoich. 

>We could insert a divide-by circuit between the knock sensor & the 
>ECU to reduce the number of pings sensed by a jumper-programmable 
>factor.

not sure what type of signal you're expecting from a (presumably 
wide-band) knock sensor, but it 'aint sound like it would work

------------------------------

From: Mazda Ebrahimi <kleenair@xxx.com>
Date: Mon, 11 Nov 1996 20:47:22 -0500
Subject: Re: drivers and sensors

S. Lastuka wrote:
> 
> I am a student at the University of Washington and I am on a team
> designing a fuel injection system for a Formula SAE car.  We are currently
> programming a 68hc11 and are looking into buying the other components that
> will be needed for our system.  We are trying to find a place that sells
> injector drivers (peak and hold).  We have heard that Cherry Electronics
> sells these drivers but we are having some trouble getting a phone number
> for Cherry.  If anyone knows of a place that sells drivers we would
> appreciate some information ie phone number, price, address.  Thank you,
> 
> Sean Lastuka


Hi Sean
The information you are looking for is this:

Cherry Semiconductor Corporation
2000 South Country Trail
East Greenwich, RI 02818
TEL:  (401) 885-3600
FAX:  (401) 885-5786

More than likely they will refer you to a local distributor.  Ask them 
for their "Automotive IC" and "Power Conversion IC Data Book" catalogs. 
 Good Luck at the competition

Mazda Ebrahimi

------------------------------

From: RABBITT_Andrew@xxx.au
Date: Tue, 12 Nov 1996 11:13:58 est
Subject: re: O2 Sensor Open/Close Loop

> The target A/F ratio during WOT can varry from engine to engine.  

this is true, but not in the way you suggest below,

>More specifically, it is related to fuel pressure, fuel injector 
>nozzle design, and injector location.  

this is not true. inasmuch as the effects of these variables are quite 
small to the point of being negligible.

>The objective is to deliver the correct amount of fuel in fine 
>particles to the combustion chamber.  So theoredically, if all the 
>fuel was vaporized, you would not need a WOT enrichment.  

this is also not true.  I get the idea you've confused WOT A/F with 
acceleration enrichment.  WOT is usually richer than stoich because 
this produces best power for thermodynamic reasons.  Acceleration 
enrichment (which also happens at part load) is to maintain the 
setpoint A/F by compensating for manifold wetting effects due to 
changing manifold pressures.

>Therefore, on multi port fuel injection systems with higher 
>pressures, the WOT A/F is very close to stoichiometric.  In fact, 
>some newer vehicles (1996) do not go to open loop during WOT! 

given the above, I find this (very) hard to believe, however if you 
can quote sources, I'd be interested.

Andrew Rabbitt
Orbital Engine Company
Perth, Australia.

------------------------------

From: RABBITT_Andrew@xxx.au
Date: Tue, 12 Nov 1996 11:19:00 est
Subject: re: 2 Stroke Injection

>On a related note: What's up with Orbital Engine's direct 2-stroke 
>injection?

Lots, but in a few words, check out the following web address:

	http://www.orbeng.com.au

Andrew Rabbitt
Orbital Engine Company
Perth, Australia

------------------------------

From: pantera@xxx.com (David Doddek)
Date: Mon, 11 Nov 1996 23:19:05 -0600
Subject: Re: drivers and sensors

>I am a student at the University of Washington and I am on a team 
>designing a fuel injection system for a Formula SAE car.  We are currently
>programming a 68hc11 and are looking into buying the other components that
>will be needed for our system.  We are trying to find a place that sells
>injector drivers (peak and hold).  We have heard that Cherry Electronics
>sells these drivers but we are having some trouble getting a phone number
>for Cherry.  If anyone knows of a place that sells drivers we would
>appreciate some information ie phone number, price, address.  Thank you, 
>
>Sean Lastuka   
>
>
Most likely any distributor you will find for cherry will sell then only in
large quantities.  It is best to ask for samples.  The part that you will
want is the cs452 or cs453.  If you cannot get a sample, I can sell you a
couple that I have.

David J. Doddek                                          |pantera@xxx.com
Owner SGD Electronics & Development Engr for Caterpillar |h 309 685-7965
Formula SAE Team Sidewinder 94-95                        |w 309 578-2931
89 T-bird SC,  69 Fairlane w/SGD EFI                     |fx 217 428-4686
74 Pantera w/Electromotive Tec-II Twin turbos and Nitros |
Hey, If you are going to go fast, go REEEAAL FAST.       |

------------------------------

End of DIY_EFI Digest V1 #343
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