*******************

Oxygen Sensor Information
Written by Rick Kirchoff (rick@posms.cactus.org). Edited to html by Kyle Hamar
>From Terrill_Yuhas@smtpsc1.sc.pima.gov Fri Nov 4 12:42:39 1994

In response to several requests for more information about Oxygen (O2)
sensors, perhaps the following information will help.

Comment:

These procedures are only for self powered conventional sensors.
Some very new cars are using a different style sensor that is
powered. *Many* Oxygen sensors are replaced that are good to
excellent. *Many* people don't know how to test them. They
routinely last 50,000 or more miles, and if the engine is in good
shape, can last the life of the car.

What does the O2 sensor do?

It is the primary measurement device for the fuel control computer
in your car to know if the engine is too rich or too lean. The
O2 sensor is active anytime it is hot enough, but the computer
only uses this information in the closed loop mode. Closed loop
is the operating mode where all engine control sensors including
the Oxygen sensor are used to get best fuel economy, lowest
emissions, and good power.

Should the O2 sensor be replaced when the sensor light comes on in
your car?

Probably not, but you should test it to make sure it is alive and
well. This assumes that the light you see is simply an emissions
service reminder light and not a failure light. A reminder light
is triggered by a mileage event (20-40,000 miles usually) or
something like 2000 key start cycles. EGR dash lights usually fall
into the reminder category. Consult your owners manual, auto repair
manual, dealer, or repair shop for help on what your light means.

How do I know if my O2 sensor may be bad?

If your car has lost several miles per gallon of fuel economy and
the usual tune up steps do not improve it. This *is not* a
pointer to O2 failure, it just brings up the possibility. Vacuum
leaks and ignition problems are common fuel economy destroyers.
As mentioned by others, the on board computer may also set one of
several failure "codes". If the computer has issued a code
pertaining to the O2 sensor, the sensor and it's wiring should
be tested. Usually when the sensor is bad, the engine will show
some loss of power, and will not seem to respond quickly.

What will damage my O2 sensor?

Home or professional auto repairs that have used silicone gasket
sealer that is not specifically labeled "Oxygen sensor safe",
"Sensor safe", or something similar, if used in an area that
is connected to the crankcase. This includes valve covers, oil
pan, or nearly any other gasket or seal that controls engine oil.
Leaded fuel will ruin the O2 sensor in a short time. If a car is
running rich over a long period, the sensor may become plugged up
or even destroyed. Just shorting out the sensor output wire will
not usually hurt the sensor. This simply grounds the output
voltage to zero. Once the wiring is repaired, the circuit
operates normally. Undercoating, antifreeze or oil on the
*outside* surface of the sensor can kill it. See how does an
Oxygen sensor work.

Will testing the O2 sensor hurt it?

Almost always, the answer is no. You must be careful to not
*apply* voltage to the sensor, but measuring it's output voltage
is not harmful. As noted by other posters, a cheap voltmeter
will not be accurate, but will cause no damage. This is *not*
true if you try to measure the resistance of the sensor.
Resistance measurements send voltage into a circuit and check the
amount returning.

How does an O2 sensor work?

An Oxygen sensor is a chemical generator. It is constantly making
a comparison between the Oxygen inside the exhaust manifold and air
outside the engine. If this comparison shows little or no
Oxygen in the exhaust manifold, a voltage is generated. The
output of the sensor is usually between 0 and 1.1 volts. All
spark combustion engines need the proper air fuel ratio to
operate correctly. For gasoline this is 14.7 parts of air to one
part of fuel. When the engine has more fuel than needed, all
available Oxygen is consumed in the cylinder and gasses leaving
through the exhaust contain almost no Oxygen. This sends out a
voltage greater than 0.45 volts. If the engine is running lean,
all fuel is burned, and the extra Oxygen leaves the cylinder and
flows into the exhaust. In this case, the sensor voltage goes
lower than 0.45 volts. Usually the output range seen seen is
0.2 to 0.7 volts.

The sensor does not begin to generate it's full output until it
reaches about 600 degrees F. Prior to this time the sensor is
not conductive. It is as if the circuit between the sensor and
computer is not complete. The mid point is about 0.45 volts.
This is neither rich nor lean. A fully warm O2 sensor *will not
spend any time at 0.45 volts*. In many cars, the computer sends
out a bias voltage of 0.45 through the O2 sensor wire. If the
sensor is not warm, or if the circuit is not complete, the computer
picks up a steady 0.45 volts. Since the computer knows this is
an "illegal" value, it judges the sensor to not be ready. It
remains in open loop operation, and uses all sensors except the
O2 to determine fuel delivery. Any time an engine is operated
in open loop, it runs somewhat rich and makes more exhaust
emissions. This translates into lost power, poor fuel economy
and air pollution.

The O2 sensor is constantly in a state of transition between high
and low voltage. Manfucturers call this crossing of the 0.45
volt mark O2 cross counts. The higher the number of O2 cross
counts, the better the sensor and other parts of the computer
control system are working. It is important to remember that the
O2 sensor is comparing the amount of Oxygen inside and outside
the engine. If the outside of the sensor should become blocked,
or coated with oil, sound insulation, undercoating or antifreeze,
(among other things), this comparison is not possible.

How can I test my O2 sensor?

They can be tested both in the car and out. If you have a high
impedence volt meter, the procedure is fairly simple. It will
help you to have some background on the way the sensor does
it's job. Read how does an O2 sensor work first.


Testing O2 sensors that are installed

The engine must first be fully warm. If you have a defective
thermostat, this test may not be possible due to a minimum
temperature required for closed loop operation. Attach the
positive lead of a high impedence DC voltmeter to the Oxygen
sensor output wire. This wire should remain attached to the
computer. You will have to back probe the connection or use
a jumper wire to get access. The negative lead should be
attached to a good clean ground on the engine block or
accessory bracket. Cheap voltmeters will not give accurate
results because they load down the circuit and absorb the
voltage that they are attempting to measure. A acceptable
value is 1,000,000 ohms/volt or more on the DC voltage.
Most (if not all) digital voltmeters meet this need. Few
(if any) non-powered analog (needle style) voltmeters do.
Check the specs for your meter to find out. Set your meter
to look for 1 volt DC. Many late model cars use a heated
O2 sensor. These have either two or three wires instead of
one. Heated sensors will have 12 volts on one lead, ground
on the other, and the sensor signal on the third. If you have
two or three wires, use a 15 or higher volt scale on the meter
until you know which is the sensor output wire.

When you turn the key on, do not start the engine. You should
see a change in voltage on the meter in most late model cars. If
not, check your connections. Next, check your leads to make sure
you won't wrap up any wires in the belts, etc. then start the
engine. You should run the engine above 2000 rpm for two
minutes to warm the O2 sensor and try to get into closed loop.
Closed loop operation is indicated by the sensor showing several
cross counts per second. It may help to rev the engine between
idle and about 3000 rpm several times. The computer recognizes
the sensor as hot and active once there are several cross counts.

You are looking for voltage to go above and below 0.45 volts.
If you see less than 0.2 and more than 0.7 volts and the value
changes rapidly, you are through, your sensor is good. If not,
is it steady high (> 0.45) near 0.45 or steady low (< 0.45).
If the voltage is near the middle, you may not be hot yet. Run
the engine above 2000 rpm again. If the reading is steady low,
add richness by partially closing the choke or adding some propane
through the air intake. Be very careful if you work with any
extra gasoline, you can easily be burned or have an explosion.
If the voltage now rises above 0.7 to 0.9, and you can change it
at will by changing the extra fuel, the O2 sensor is usually good.

If the voltage is steady high, create a vacuum leak. Try pulling
the PCV valve out of it's hose and letting air enter. You can
also use the power brake vacuum supply hose. If this drives the
voltage to 0.2 to 0.3 or less and you can control it at will by
opening and closing the vacuum leak, the sensor is usually good.

If you are not able to make a change either way, stop the engine,
unhook the sensor wire from the computer harness, and reattach
your voltmeter to the sensor output wire. Repeat the rich and
lean steps. If you can't get the sensor voltage to change, and
you have a good sensor and ground connection, try heating it once
more. Repeat the rich and lean steps. If still no voltage or
fixed voltage, you have a bad sensor.

If you are not getting a voltage and the car has been running
rich lately, the sensor may be carbon fouled. It is sometimes
possible to clean a sensor in the car. Do this by unplugging
the sensor harness, warming up the engine, and creating a lean
condition at about 2000 rpm for 1 or 2 minutes. Create a big
enough vacuum leak so that the engine begins to slow down.
The extra heat will clean it off if possible. If not, it
was dead anyway, no loss. In either case, fix the cause of the
rich mixture and retest. If you don't, the new sensor will
fail.

Testing O2 sensors on the workbench.

Use a high impedence DC voltmeter as above. Clamp the sensor in
a vice, or use a plier or vice-grip to hold it. Clamp your
negative voltmeter lead to the case, and the positive to the
output wire. Use a propane torch set to high and the inner blue
flame tip to heat the fluted or perforated area of the sensor.
You should see a DC voltage of at least 0.6 within 20 seconds.
If not, most likely cause is open circuit internally or lead
fouling. If OK so far, remove from flame. You should see a
drop to under 0.1 volt within 4 seconds. If not likely silicone
fouled. If still OK, heat for two full minutes and watch for
drops in voltage. Sometimes, the internal connections will open
up under heat. This is the same a loose wire and is a failure.
If the sensor is OK at this point, and will switch from high to
low quickly as you move the flame, the sensor is good. Bear in
mind that good or bad is relative, with port fuel injection
needing faster information than carbureted systems.

ANY O2 sensor that will generate 0.9 volts or more when heated,
show 0.1 volts or less within one second of flame removal, AND
pass the two minute heat test is good regardless of age. When
replacing a sensor, don't miss the opportunity to use the test
above on the replacement. This will calibrate your evaluation
skills and save you money in the future. There is almost always
*no* benefit in replacing an oxygen sensor that will pass the
test in the first line of this paragraph.

--
Rick Kirchhof Austin, Texas | Experience is what you
Domain: rick@posms.cactus.org | get when you don't
Bang path: ...!cs.utexas.edu!peyote!posms!rick | get what you want.

===========================================================================






>From hotrod@Dixie.Com Tue Mar 30 11:11:25 1993
Subject: Edelbrock air/fuel ratio monitor
From: hotrod@dixie.com (The Hotrod List)
To: hotrod@dixie.com
X-Sequence: 4717
X-Archives: ece.rutgers.edu

Well....

I just bought the Edelbrock air/fuel ratio monitor and hears what I discovered.
The sensor is a Bosch PN E971-9F472-AA (a lot of numbers stamped on it, I think
this ones the Bosch part number). I believe this to be a standard three wire
conventual O2 sensor though admittedly I do not have the manufacture's
literature. The "little black box" is nothing more than little and black.
Inside there is a surge suppresser, a filter capacitor, one needed and one
redundant resistor to control the LEDs brightness, and a LM3914 Dot/Bar Display
Driver. The design is straight out of the application books with no creativity.
Did I mention the lack of input signal conditioning/filtering to remove engine/
ignition noise? Given the speed of the LM3914's comparators, this is a problem
and certainly a problem in my implementation.

The electronics clearly runs the sensor in the voltage mode drawing only
a 25nA biasing current for the LM3914's internal buffer. The sensor voltage
and air/fuel ratio have the following corresponds:

volts air/fuel Lambda
(open circuit)
=====================================
.250 15.0:1 1.02
.375 14.5:1 0.99
.500 14.0:1 0.95
.625 13.5:1 0.92
.750 13.0:1 0.88
.875 12.5:1 0.85
1.000 12.0:1 0.82

>From what I have read in the SAE Transaction pertaining to O2 sensors, this
relationship is "bull shit". :( I can not believe this mode of operation would
let the sensor go as low as .8 lambda let alone have this type of linearity.

I would have at least expected Edelbrock to use a current mode of operation.

Any comments?

My next step is to change Edelbrocks "little black box" into a current
mode of operation and call NGK in hopes of finding an affordable UEGO.

John S. Gwynne
jsg@magnus.acs.ohio-state.edu

----------
Posted by: John S Gwynne




>From hotrod@Dixie.Com Thu Apr 1 12:39:23 1993
Subject: Re: Edelbrock air/fuel ration monitor
From: hotrod@dixie.com (The Hotrod List)
To: hotrod@dixie.com
X-Sequence: 4777
X-Archives: ece.rutgers.edu

Bob Valentine writes:

> From the tone, I can tell that the design is not a good one.
>However, I'd like to get away from the DVM hanging under my dash....
>Would using a 3914 (I used those in grade school for really cool audio
>power meters...) suffice with a 1 wire O2 sensor?

>From what I've seen so far the electronic portion needs some improvements. The
input signal will have to be conditioned/filtered to gain a steady display. The
signal line from the sensor has no loading at all to reduce ignition noise. In
addition, I do not like the voltage generation mode of operation. From some of
the generic voltage-vs-current curves (as a function of lambda), in the SAE
transactions, I intend to find a load line that will maximize the sensor's
dynamic range and hope it works well for this sensor too. In the circuit to do
this, I will include some filtering. The use of the LM3914 is a good choice,
but I don't see it doing the job alone for a 1 wire or 3 wire sensor.


> [chart showing voltage, air/fuel, lambda deleted]
> So then, is this chart valid?

I don't think so. IMHO I think Edelbrock wanted a product to match MSD's O2
sensor, which has only one tri-color LED to indicate the mixture condition.
Their gimmick was to add more LED's and who would know if these LED's had any
real meaning? They almost flash in a believable fashion.


> I don't have the reference here anymore, but I belive a LM3915
>works on current, rather than voltage. Nice thing about this series
>is that you can chain several of them together to get a rather precise
>display. (ie., a 20 segment display... hell, just carpet the dash with
>those plug in segments! 8^>)

The LM3914 has a linear display and the LM3915 is logarithmic. Both are a
function of input voltage, and both will let you carpet the dash :) .


> If you can find a UEGO, let me know. Last I heard they were
>made of "Unobtanium", and way out of bounds on price.

The data sheet I have from HORIBA on their UEGO sensor for the MEXA-110 says
it's made of zirconia and ceramic :) . But at a price of $900, it is
unobtainable. If I can find the time, I'm still going to look for an affordable
one.

[I mentioned awhile back the MOTES A/F analyzer that competes with the MEXA
but costs less than Horiba's sensor. They told me they were using, I believe,
the Bosch UEGO sensor that is much cheapter than the one Horiba uses.
Someone else noted that one model of Honda lean burn engine uses a UEGO.
Might want to check the archives for that info. They're at ece.rutgers.edu
JGD]

John S. Gwynne
jgwynne@magnus.acs.ohio-state.edu

----------
Posted by: John S Gwynne



>From hotrod@Dixie.Com Mon Jul 26 12:46:06 1993
Subject: Re: More about Holleys
From: hotrod@dixie.com (The Hotrod List)
To: hotrod@dixie.com
X-Sequence: 5884
X-Archives: ece.rutgers.edu

> O2 Sensor setup, etc <

I drilled a hole in the cast iron exhaust manifold right before the outlet
flange, and reamed it out until an 18mm anti-fouling spark plug adaptor was
a hammer fit. I ground down the adaptor until its inner end was flush with
the interior wall of the manifold, and then welded it in place.

The O2 sensor I used was a freebie 1-wire type. A 3-wire is better for
reasons I'll go into in a bit, but costs more. I picked up ground locally
using a valve cover bolt through a loop soldered in the end of the ground
wire, and connected the O2 sensor to its mate, solder and shrink-wrap.
I used some automotive "trailer wire" (the 4-conductor ribbon used for
hooking up auxiliary lights etc.) which seems to be taking the heat
and grease reasonably well. The reason for taking a local (engine block)
ground is to minimize any error induced by body/block return currents
and any voltage offset that might develop from loads like A/C, lights
if you used the dash as ground.

I am using a spare analog VOM to read O2 volts; it seems to be working
well enough, even though I've been told that the O2 sensor needs a very
high load impedance. This meter has about 100Kohms (50K/volt, 2.5V scale)
and I think it's about on the edge of affecting the sensor output
accuracy; if I switch to the next lower scale I get a slightly lower
value reading indicating Zload sensitivity to me.

The reading ranges from 0 to 1V (approx), with 0 indicating lean and 1V
indicating rich. 0.5 is supposed to be stoichemetric. When warm I seem
to be pegged rich, or close to it, except for a "hole" during throttle
transitions.

The one-wire sensor depends on exhaust heat to activate it; the element
has to be pretty hot to develop any voltage and low temperatures result
in a reduction or absence of output. I find that there's not enough heat
at idle to keep the sensor fired up. If I idle for more than a few seconds
the output voltage starts to decay. The other thing is that it takes a
while to start reading. For a tailpipe test rig I made, a 3-wire was a
necessity since by that point there's not enough heat ever.

For a permanent installation I think the best solution would be to use
a small panel meter with a single-supply op amp as a unity gain buffer
and a calibration resistor to get 1V full scale. A shunt resistor from
amplifier output to ground might help the amp in the low end. I tried
cobbling up a bar graph display using an old LM3914 I had in the parts-
is-parts tin but it seems to have developed an attitude. For some
reason Radio Shack has stopped selling these although they still sell the
bar graph displays.

----------
Posted by: emory!mlb.semi.harris.com!jws (James W. Swonger)




>From hotrod@Dixie.Com Mon Aug 16 21:12:16 1993
Subject: 02 sensor help!
From: hotrod@dixie.com (The Hotrod List)
To: hotrod@dixie.com
X-Sequence: 6040
X-Archives: ece.rutgers.edu


> O2 Sensor setup, etc <

.....

>The O2 sensor I used was a freebie 1-wire type. A 3-wire is better for
reasons I'll go into in a bit, but costs more.

We are interested in putting an 02 sensor in a Datsun 240Z SCCA ITS class
road race car. The Datsun has a six into two header (where three cylinders
being fed by one carburetor) into a dual exhaust system. We are interested in
monitoring the air / fuel ratio of each carb (3 cylinders) while the car is at
speed to determine efficiency at high RPM.

We understand K & N makes an air/fuel monitor that retails for $139.00. Can we
inexpensively duplicate this device or do you have a better, less expensive
alternative.

Also, does the 02 sensor develop its own voltage or is it a variable
resistance device? Any explanation (reference material, etc.) on how this
operates would be greatly appreciated.


Roger Hensley
Patriot Motorsports
1099 N. 16th St.
Otsego, Mi 49078

[Cyberdyne makes an in-dash A/F indicator that lists for $29 in Summit's
catalog. Don't pay a dime more. Many of these things are labeled with
wide range A/F ratios. Since the standard O2 sensor covers a narrow range
around stoich, this labeling is fraudulent. As long as standard production
O2 sensors are used (UEGOs sensors by themselves cost several hundred bux),
all the displays must work the same. If you want an analog readout,
a simple analog meter with an op-amp buffer does the trick. the voltage
range from the sensor is 0-1 volt at high impedance so gain isn't necessary;
only buffering.

For references, see the archives plus SAE's "Sensors and Actuators"
publication from the last few years. More info than you can stand.
Remember though, lead-free gas only. JGD]
----------
Posted by: emory!dcmdc.dla.mil!xgg3511 (Roger Hensley)



>From hotrod@Dixie.Com Thu Sep 9 19:12:41 1993
Subject: Air / Fuel Guage results & Thanks.
From: hotrod@dixie.com (The Hotrod List)
To: hotrod@dixie.com
X-Sequence: 6309
X-Archives: ece.rutgers.edu



Just a word to say thanks to all those people that helped us out on our
Air/Fuel meter question I posted a few weeks ago. We bought a couple of
Cyberdyne Air/Fuel Gauges from SUMMIT for $30.99 and installed a BOSCH O2
sensors at each collector on my friends (Andy) Datsun 240Z SCCA ITS race car.


During warm ups at Grattan raceway on 04 September both gauges read two bars
too rich (what ever two bars mean). The car was brought in and the carbs
leaned out. Back on the track the gauges read center or stoch. and Andy's
times improved down the straight and throughout the course. Saturday Andy
qualified second in class behind a 280Z. On Sunday the gauges were still
reading stoch and Andy won the South Bend regional race being chased by the
280Z. On Monday he qualified for the Western Michigan regional races 3rd
overall and 1st in class in the rain. The Cyberdynes were now reading two bars
too lean; however, we did not readjust the carbs because the race was
scheduled to be run later in the day and the forcast was for clear skies. I
figure the cooler temps were making the air a little denser thus the reason
for the lean condition. The guess was correct. During the race the skies were
clear and temp was warming up to what it had been Saturday and Sunday. Andy
won the Monday race again being chased by the 280Z.


We learned a lot using the Cyberdynes. They aren't perfect but do give an
adequate indication of what is going on. By the way we used 75% HI OCTANE
unleaded fuel and 25% leaded Racing Fuel. It didn't seem to bother the O2
sensors. Anyway Thanks a Bunch!

Roger Hensley
Patriot Motorsports

[The guys down at Ga Tech F-SAE team have been using lambda sensors with
leaded fuel for quite some time. They were fortunate to have had GM
donate a whole box full of sensors to the effort. They tell me the sensor
will last for a few hours of dyno running. The first indication
of poisoning is sluggish response. Sounds like yours should be good
for a couple of events. JGD]

----------
Posted by: emory!dcmdc.dla.mil!xgg3511 (Roger Hensley)




>From hotrod@Dixie.Com Mon Oct 11 23:39:00 1993
Subject: Re: custom O2 gague (& others)
From: hotrod@dixie.com (The Hotrod List)
To: hotrod@dixie.com
X-Sequence: 6678
X-Archives: ece.rutgers.edu

--------

In message , you write:

|
| these questions deal with the air/fuel mix sensor (like cyberdyne's
| in the summit catalog):
| - where does the sensor need to be located, ie real close to the
| engine (reporting on just one cylinder (and hoping it is
| 'typical')), or can it be put down on the collector, so it would
| report on how the cylinders (as a whole) are doing?
| - how does the placement affect the accuracy/linearity (or what else?)

Sensor location is important for the non-heated EGO sensor. Too close
to the engine and it will become too hot and shorten the life
expectancy. Too far way and the sensor may not stay warm enough to
work at idle. Location is not a problem for the thick film heated
sensors (TFHEGO), and placement in the collector is fine.

| - does the sensor come with a full spec sheet (ie what the voltage or
| resistance is for different a/f ratios, or can one be obtained?
|
| which leads me to the thought that brought on the questions: i want
| to make a small 'gage' for a/f ratios (i don't like the look of the
| cyberdyne unit), with 5 lights or led's on it:
| 1) red -> way too lean
| 2) yellow -> fuel-economy cruise (slightly lean)
| 3) green -> stoich
| 4) yellow -> acceleration (slightly rich)
| 5) red -> way too rich
|


As far as I know (which may not be much :) ), all of these gauges for
under $150 that claim to cover such a wide A/F range (specifically on
the rich side) ARE bullshit... I bought the Edelbrock air/fuel
monitor (see post end of March/93 in the archives -- ece.rutgers.edu)
and traced out the circuit. It uses a TFHEGO in the voltage
generation mode which can really only indicate 2-states (rich/lean).
Needless to say that I was not happy and you should not waste your
money on that one.... Before you buy one of these, run down to that
auto parts store and get a generic 3-wire sensor.

To build a wide-range Air/Fuel meter, you need something like a UEGO
sensor (again see the archives) that would use a oxygen cramming
method or oxygen bias method (see SAE journals). This can cover the
range .6



>From hotrod@Dixie.Com Tue Jul 5 13:15:15 1994
Subject: Honda LAF sensor
From: hotrod@dixie.com (The Hotrod List)
To: hotrod@dixie.com
X-Sequence: 8868
X-Archives: ece.rutgers.edu
X-Comment: Send subscription and drop requests to hotrod-request@dixie.com
X-Comment: Send comments and trouble reports to jgd@dixie.com


The wide-range O2 sensor used in some of the Hondas is called an LAF
sensor in England, UEGO over here. There's a chart in the October 1991
Car Design & Technology which shows the response curves of a
conventional Lambda O2 sensor and the Honda LAF sensor

The LAF's response isn't linear, as depicted on the chart. It starts
at about -5v at 10:1 A/F, moving up sharply to about -1v at stoich, then
progressing slowly up to maybe +2v at 25:1.


----------
Posted by: emory!chaos.lrk.ar.us!dave.williams (Dave Williams)




>From KEN_MOSHER@gmgate.IMD.Sterling.COM Tue Apr 20 15:21:53 1993
Date: 20 Apr 1993 15:18:26 U
Subject: Injectors
From: "KEN MOSHER"

SUBJECT: Injectors
I ran across the following information about injectors and thought it may be of
general interest:

Manufacturer Part # Flow @ 45 psi
================================================
Lucas 5208006 15.8 lbs/hr
Lucas 5207011 23.9 lbs/hr
Bosch (Stock GN) 0-280-150-218 29.8 lbs/hr
Bosch (Supercoupe) 0-280-150-756 32.0 lbs/hr
Bosch (Porsche) 0-280-150-213 33.0 lbs/hr
Bosch 0-280-150-911 33.0 lbs/hr
Lucas 5207009 33.2 lbs/hr
Lucas 5207008 40.1 lbs/hr
Bosch 0-280-150-803 40.0 lbs/hr
Lucas 5107010 52.0 lbs/hr
AC Rochester MSD 2014 72.0 lbs/hr
Bendix (red) GM25500139 82.0 lbs/hr
AC Rochester MSD 2015 96.0 lbs/hr
Bendix (white) GM (alcohol) 180.0 lbs/hr

This data was gathered from ATR's literature enclosed in their 7th injector
kit. Also, they note that the rated flow is NOT at rail pressure. The value
at 45 psi is the differential pressure across the injector. In other words, if
the fuel pressure is 65 psi @ WOT and the boost is set at 20 psi, the
differential pressure is 45 psi.

They also included an A/F ratio graph that confirmed what I saw on the chassis
dyno with my car ... namely that under boost the car should hover around 12.5:1
for best HP and detonation resistance. A crude ASCII rendering of the graph is
below:

___
| ! ******* ! ! ! !
| ** ****** ! ! !
| * ! ! *****! ! !
BHP| * ! ! ** ! !
| * ! ! ! ** ! !
|* ! ! ! ** ! !
___| ! ! ! *! !
| RICH ! CORRECT ! LEAN ! LIGHT !* SEVERE!
| ! A/F ! ! KNOCK ! *KNOCK !
| ! ! ! ! * !
| ! ! ! ! * !
| ! ! ! ! * !
| ! ! ! ! * !
| ! ! ! ! * !
___|_________|____________|_______|_______|________|
| | | | | |
11.0 12.0 13.0 13.5 14.0 14.7
Air/Fuel Ratio