DIY_EFI Digest Monday, 16 November 1998 Volume 03 : Number 549 In this issue: Re: Injector Impedance how low can i go... Re: EFI Please???? Re: trac. contr. Re: CarPROM software ??? TCC Re: Injector Impedance how low can i go... O2 Sensor testing info O2 Sensor testing info Re: Upload GM TBI to 4bbl intake Steering Wheel Switches Re: Steering Wheel Switches Re: GM TBI to 4bbl intake Re: Injector Impedance how low can i go... See the end of the digest for information on subscribing to the DIY_EFI or DIY_EFI-Digest mailing lists. ---------------------------------------------------------------------- From: Richard Wakeling Date: Mon, 16 Nov 1998 22:13:26 +1100 Subject: Re: Injector Impedance how low can i go... Hi Stuart, I recently discovered that the "808" seems to have the ability to drive a couple of low impedence injectors in peek and hold mode. There is provision already on the PCB to use the existing saturation injector driver in peek and hold mode by, 1) Disconnecting the wire D10 at the ECU. This is the injector driver's ground circuit (source) which goes to engine ground. 2) Put jumper wire between D9 and D10 on ECU, this will put a 0.1 ohm resistor which is already on the PCB in series with the injector drivers source and ground. This 0.1 ohm resistor is used to sense current for Peek & hold. I have not tried this wiring modification myself and I would suggest that a check should be made to see if the injector driver controller used and driver mosfets used in the "808" are the same as in the "749" which has two injector drivers when used for the Sunbird's four low impedence injectors. Cheers Richard. Stuart Bunning wrote: > > I am using a GM 1227808 Aussie ECU. > I want to know what impedance injectors it can drive. > on a V8 we have 8 16ohm injectors in parallel about 2 Ohmn load. > > I want to play with a TBI that has 2 injectors which are about 1.8 Ohm each > so if i parallel then up the ecu will see about .9 Ohm. Will this melt the > ECU ? > > I guess I could suck it and see but I don't want to melt my ECU if it can > help it. > > I guess what i am asking is what is normal impedance of TBI injectors used > in 808/165's > > The TBI i am wanting to play with is off a Aussie FORD EA 6 cylinder Single > point if anyone is interested... > > P.S > > I don't want to build a external injector driver or modify the ECU. > > Thanks > Stuart Bunning.. > > ------------------------------ From: jb24@xxx.com Date: Mon, 16 Nov 1998 08:42:49 -0500 Subject: Re: EFI Please???? We engineers who build Jeeps have a long list of things that a Jeep must do, at the top is cross the Rubicon Trail outside of Lake Tahoe under it's own power. This is the 10 that all off-road trails are measured against. It is good to hear every once in a while that our efforts are appreciated. cosmic.ray@xxx.com (Raymond C Drouillard) on 11/13/98 02:59:00 AM Please respond to diy_efi@xxx.edu To: diy_efi@xxx.edu cc: diy_efi@xxx.edu Subject: Re: EFI Please???? On Thu, 12 Nov 1998 18:25:45 +0000 H Villemure writes: >If you had taken the time to read my reply correctly- I also mentioned >tank-like reliability (or was it in another post), which to the best of my >knowledge still eludes most american cars. I have found the Jeeps that I have owned have tank-like reliability. My Jeeps end up taking more punishemnt than ordinary cars, and they stand up to it. Ray Drouillard ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866] ------------------------------ From: Tom Sharpe Date: Mon, 16 Nov 1998 08:42:04 -0600 Subject: Re: trac. contr. Greg Hermann wrote: > Yes, one of the better full time units built, but one FAR better that no > one knows about was used in the Jensen Interceptor cars: > It used THREE Hy-Vo chains, each 1" wide, with sprockets which were > staggered by 1/3 of a tooth from each other, so that chain loadeing and > noise was spread out and quieted. It did not use a limited slip unit. It > had two one way (sprag type) clutches, and two slip limiting gear sets. Greg, I had a Warren "Dual-Drive" rear posi in a CJ (D44) with a 482 and Powerglide w/ brake. It had two, both way roller clutches in it, (looked like an automatic front hub, except bigger). It was the smoothest posi I ever saw. Completely unlocked under normal conditions and completely locked under power without and indication of what happened. At Gravelrama one year, I had just finished cleaning the rear brakes and had one rear wheel off the ground when some "Inspectors" came around. You could grab the back tire, shake it, then rotate it forward... then backward... while in park. I said "It must have a broken axle" then set it down and drove into the staging lanes. You should have seen the look on their faces. I'll pay a finder's fee to locate another..... Regards Tom ------------------------------ From: "John Hess" Date: Mon, 9 Nov 1998 17:59:03 -0600 Subject: Re: CarPROM software ??? Only if you already know all the data locations and the conversion variables. It is nothing more than a fancy binary file editor. - -----Original Message----- From: andy quaas To: diy efi Date: Monday, November 09, 1998 11:32 AM Subject: CarPROM software ??? >Anybody heard of this carprom software from arizona speed and marine? >Found it on their webpage. Its for editing "GM ecms and pcms". Is >this stuff any good? > >Andy Q > > > > >_________________________________________________________ >DO YOU YAHOO!? >Get your free @xxx.com > > ------------------------------ From: rbraun@xxx.net Date: Mon, 16 Nov 1998 10:46:01 -0400 Subject: TCC I didn't like the way my TCC worked either so rather than work with the prom, I added a circut to delay TCC by 12 seconds, this seemed to work good until I slammed the door on the circut board and blew the fuse to the ECM. Midnite at the mall after a movie with the GF. BTW, '91 GTA 5.7L A4, TCC on at 35 MPH with anything under 75% throttle, delay was nice I could get to cruise speed before lockup and never felt it go in,never got a check engine light either. Randy Braun '77 C-10 pick-up, DFI-Tuned Port, 350 '82 Firebird, DFI, ZZ3 '91 GTA, Stock ------------------------------ From: "Andrew F. Gunnesch" Date: Mon, 16 Nov 1998 11:15:53 -0500 Subject: Re: Injector Impedance how low can i go... On Nov 16, 10:13pm, Richard Wakeling wrote: > Subject: Re: Injector Impedance how low can i go... > Hi Stuart, > I recently discovered that the "808" seems to have the ability to drive > a couple of low impedence injectors in peek and hold mode. There is > provision already on the PCB to use the existing saturation injector > driver in peek and hold mode by, Any idea if this works for the '165 ECMs as well then? Since the 808 and 165 seem to be fairly similar beasts. This would really be a boon if you could take a 165 ECM and convert it from using 8 saturation injectors to 8 peak-and-hold injectors, no? ------------------------------ From: am018 Date: Mon, 16 Nov 1998 16:19:16 +0000 Subject: O2 Sensor testing info This is a multi-part message in MIME format. - --------------C79FFB9E7CA1C7989CA7BEDF Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Attached is the info on O2 sensors from the defunct David Kirchoff Web site. This has been OCR scanned in and may have errors Andy - --------------C79FFB9E7CA1C7989CA7BEDF Content-Type: text/plain; charset=iso-8859-1; name="O2sensor.txt" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline; filename="O2sensor.txt" This info was taken from David Kirchoffs web page which is no longer avai= lable, as it was OCR scanned from a well worn print off some errors may e= xist in this version of the text. All credits to the author David Kirchoff Oxygen Sensor Information In response to several requests for more information about Oxygen (02) se= nsors, perhaps the following information will help. Comment: = These procedures are only for self powered conventional sensors. Some ver= y new cars are using a different style sensor that is powered. *Many* Oxy= gen sensors are replaced that are good to excellent. *Many* people don't = know how to test them. = O2 Sensors routinely last 50,000 or more miles, and if the engine is in g= ood shape, can last the life of the car. = What does the 02 sensor do? It is the primary measurement device for the fuel control computer in you= r car to know if the engine is too rich or too lean. The 02 sensor is act= ive 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 eng= ine control sensors including the Oxygen sensor are used to get best fuel= economy, lowest emissions, and good power. = Should the 02 sensor be replaced when the sensor light comes on in your c= ar? Probably not, but you should test it to make sure it is alive and well. T= his assumes that the light you see is simply an emissions service reminde= r light and not a failure light. A reminder light is triggered by a milea= ge event (20-40,000 miles usually) or something like 2000 key start cycle= s. EGR dash lights usually fall into the reminder category. Consult your = owners manual, auto repair manual, dealer, or repair shop for help on wha= t your light means. = How do I know if my 02 sensor may be bad? If your car has lost several miles per gallon of fuel economy and the usu= al tune up steps do not improve it. This is * not* a pointer to 02 failur= e, 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 02 sensor, the sensor and it's wiring sh= ould 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 02 sensor? Home or professional auto repairs that have used silicone gasket sealer t= hat is not specifically labelled "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 02 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 wi= ll not usually hurt the sensor (!!!??). This simply grounds the output vo= ltage to zero. Once the wiring is repaired, the circuit operates normally= =2E Undercoating, antifreeze or oil on the *outside* surface of the senso= r can kill it. See how does an Oxygen sensor work. = = Will testing the 02 sensor hurt it? Almost always, the answer is no. You must be careful to not *apply* volta= ge to the sensor, but measuring it's output voltage is not harmful. As no= ted by other posters, a cheap voltmeter will not be accurate, but will ca= use no damage. This is *not* true if you try to measure the resistance of= the sensor. = Resistance measurements put a voltage across circuit and measure the resi= stance from the resulting current. How does a 02 sensor work? An Oxygen Sensor is a chemical generator. It is constantly making a compa= rison between oxygen content of the gas inside the exhaust manifold and a= ir outside the engine. If this comparison shows little or oxygen in the = exhaust manifold, a voltage is generated. The output of the sensor is usu= ally between 0 and 1.1 volts. All spark combustion engines need the prope= r air fuel ratio to operate correctly. For petrol this is 14.7 parts of a= ir to one part of fuel. When the engine has more fuel than needed, all av= ailable Oxygen is consumed in the cylinder and gasses leaving through the= exhaust will 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 t= he extra Oxygen leaves the cylinder and flows into the exhaust. In this c= ase, the sensor voltage goes lower than 0.45 volts. Usually the output ra= nge seen is 0.2 to 0.7 volts. The sensor does not begin to generate its f= ull output until it reaches about 600 degrees F. Prior to this time the s= ensor is not conductive. It is as if the circuit between the sensor and c= omputer is not complete. The mid point is about 0.45 volts. This is neith= er rich nor lean. Note that a fully warm O2 sensor ***will not spend any = time at 0.45 volts even if the fuel injection system is working perfectly= =2E In many cars, the computer sends out a bias voltage of 0.45 through t= he O2 sensor wire. If the sensor is not warm, or if the circuit is not co= mplete, the computer picks up a steady 0.45 volts. Since the computer kno= ws this is an "illegal" value, it judges the sensor to not be ready. It r= emains in open loop operation, W and uses all sensors except the O2 to de= termine fuel delivery. = When an engine is operated in open loop, it runs somewhat rich and makes= more exhaust emissions. This translates into lost power, poor fuel econo= my and air pollution. The O2 sensor is constantly in a state of transitio= n between high and low voltage. Manufacturers call this crossing of the 0= =2E45 volt mark 02 cross counts. The higher the number of O2 cross counts= , the better the sensor and other parts of the computer control Ny,1tem a= re working. It important to remember that the O2 sensor is comparing the = amount of Oxygen In exhaust gas with the atmosphere 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 02 sensor? They can be tested both in the car and out. If you have a high impedance = 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 sens= or work first. Testing 02 sensors that are installed The engine must first be fully warmed through to a minimum temperature r= equired for closed loop operation. Attach the positive lead of a high imp= edance DC voltmeter to the Oxygen sensor output wire. This wire should re= main attached to the ECU computer. You will have to back probe the connec= tion or use a jumper wire to get access. The negative lead should be atta= ched to a good clean ground on the engine block or the case of the ECU. C= heap voltmeters will not give accurate results because they load down the= circuit and absorb the voltage that they are attempting to measure. A ac= ceptable value is 1,000,000 ohms/volt or more on the DC voltage. Generall= y digital multimeters/voltmeters can safely be used but ordinary analogu= e voltmeters/multimeters could both damage the sensor and give inaccurat= e results.(if any) non-powered analogue meters do. = Most late model cars use a heated 02 sensor. These have either two or th= ree 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 mak= e sure you won't wrap up any wires in the belts, etc. then start the engi= ne. You should run the engine above 2000 rpm for two minutes to warm the = O2 sensor and try to get into closed loop. The sensor showing several cro= ss counts per second indicates closed loop operation. It may help to rev = the engine between idle and about 3000 rpm several times. The computer recogn= ises the sensor as hot and active once there are several cross counts. Yo= u are looking for voltage to go above and below 0.45 volts. If you see le= ss than 0.2 and more than 0.7 volts and the value changes rapidly, you ar= e 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 stead= y 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 gasol= ine, 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 ext= ra fuel, the 02 sensor is usually good. If the voltage is steady high, cr= eate a vacuum leak. Try pulling the PCV valve out of it's hose and lettin= g 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 yo= u are not able to make a change either way, stop the engine, unhook the s= ensor 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 connectio= n, 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 carb= on 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 might = clean it off 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 02 sensors on the workbench. Use a high impedance DC voltmeter as above. Clamp the sensor in a vice, o= r use a pliers or vice-grips to hold it. Clamp your negative voltmeter le= ad to the case and the positive to the output wire of the sensor. 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 a= t 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 s= ee a drop to under 0.1 volt within 4 seconds. If not likely silicone foul= ed. If still OK, heat for two full minutes and watch for drops in voltage= =2E 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 sen= sor is good. Bear in mind that good or bad is relative, with port fuel in= jection needing faster information than carburettor systems. ANY 02 senso= r that will generate 0.9 volts or more when heated, and show 0.1 volts or= less within one second of flame removal, AND pass the two minute heat te= st is good regardless of age. When replacing a sensor, don't miss the op= portunity 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= =2E -.- -.-.- -.- -.- .................,,....... = Rick Kirchhof Austin, Texas I Experience is what you Domain: rick@xxx.org I get when you don't Bang path: . .. !cs.utexas.edu!peyote!~)~~~ms!rick I get what you want. - --------------C79FFB9E7CA1C7989CA7BEDF-- ------------------------------ From: am018 Date: Mon, 16 Nov 1998 16:19:16 +0000 Subject: O2 Sensor testing info This is a multi-part message in MIME format. - --------------C79FFB9E7CA1C7989CA7BEDF Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Attached is the info on O2 sensors from the defunct David Kirchoff Web site. This has been OCR scanned in and may have errors Andy - --------------C79FFB9E7CA1C7989CA7BEDF Content-Type: text/plain; charset=iso-8859-1; name="O2sensor.txt" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline; filename="O2sensor.txt" This info was taken from David Kirchoffs web page which is no longer avai= lable, as it was OCR scanned from a well worn print off some errors may e= xist in this version of the text. All credits to the author David Kirchoff Oxygen Sensor Information In response to several requests for more information about Oxygen (02) se= nsors, perhaps the following information will help. Comment: = These procedures are only for self powered conventional sensors. Some ver= y new cars are using a different style sensor that is powered. *Many* Oxy= gen sensors are replaced that are good to excellent. *Many* people don't = know how to test them. = O2 Sensors routinely last 50,000 or more miles, and if the engine is in g= ood shape, can last the life of the car. = What does the 02 sensor do? It is the primary measurement device for the fuel control computer in you= r car to know if the engine is too rich or too lean. The 02 sensor is act= ive 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 eng= ine control sensors including the Oxygen sensor are used to get best fuel= economy, lowest emissions, and good power. = Should the 02 sensor be replaced when the sensor light comes on in your c= ar? Probably not, but you should test it to make sure it is alive and well. T= his assumes that the light you see is simply an emissions service reminde= r light and not a failure light. A reminder light is triggered by a milea= ge event (20-40,000 miles usually) or something like 2000 key start cycle= s. EGR dash lights usually fall into the reminder category. Consult your = owners manual, auto repair manual, dealer, or repair shop for help on wha= t your light means. = How do I know if my 02 sensor may be bad? If your car has lost several miles per gallon of fuel economy and the usu= al tune up steps do not improve it. This is * not* a pointer to 02 failur= e, 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 02 sensor, the sensor and it's wiring sh= ould 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 02 sensor? Home or professional auto repairs that have used silicone gasket sealer t= hat is not specifically labelled "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 02 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 wi= ll not usually hurt the sensor (!!!??). This simply grounds the output vo= ltage to zero. Once the wiring is repaired, the circuit operates normally= =2E Undercoating, antifreeze or oil on the *outside* surface of the senso= r can kill it. See how does an Oxygen sensor work. = = Will testing the 02 sensor hurt it? Almost always, the answer is no. You must be careful to not *apply* volta= ge to the sensor, but measuring it's output voltage is not harmful. As no= ted by other posters, a cheap voltmeter will not be accurate, but will ca= use no damage. This is *not* true if you try to measure the resistance of= the sensor. = Resistance measurements put a voltage across circuit and measure the resi= stance from the resulting current. How does a 02 sensor work? An Oxygen Sensor is a chemical generator. It is constantly making a compa= rison between oxygen content of the gas inside the exhaust manifold and a= ir outside the engine. If this comparison shows little or oxygen in the = exhaust manifold, a voltage is generated. The output of the sensor is usu= ally between 0 and 1.1 volts. All spark combustion engines need the prope= r air fuel ratio to operate correctly. For petrol this is 14.7 parts of a= ir to one part of fuel. When the engine has more fuel than needed, all av= ailable Oxygen is consumed in the cylinder and gasses leaving through the= exhaust will 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 t= he extra Oxygen leaves the cylinder and flows into the exhaust. In this c= ase, the sensor voltage goes lower than 0.45 volts. Usually the output ra= nge seen is 0.2 to 0.7 volts. The sensor does not begin to generate its f= ull output until it reaches about 600 degrees F. Prior to this time the s= ensor is not conductive. It is as if the circuit between the sensor and c= omputer is not complete. The mid point is about 0.45 volts. This is neith= er rich nor lean. Note that a fully warm O2 sensor ***will not spend any = time at 0.45 volts even if the fuel injection system is working perfectly= =2E In many cars, the computer sends out a bias voltage of 0.45 through t= he O2 sensor wire. If the sensor is not warm, or if the circuit is not co= mplete, the computer picks up a steady 0.45 volts. Since the computer kno= ws this is an "illegal" value, it judges the sensor to not be ready. It r= emains in open loop operation, W and uses all sensors except the O2 to de= termine fuel delivery. = When an engine is operated in open loop, it runs somewhat rich and makes= more exhaust emissions. This translates into lost power, poor fuel econo= my and air pollution. The O2 sensor is constantly in a state of transitio= n between high and low voltage. Manufacturers call this crossing of the 0= =2E45 volt mark 02 cross counts. The higher the number of O2 cross counts= , the better the sensor and other parts of the computer control Ny,1tem a= re working. It important to remember that the O2 sensor is comparing the = amount of Oxygen In exhaust gas with the atmosphere 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 02 sensor? They can be tested both in the car and out. If you have a high impedance = 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 sens= or work first. Testing 02 sensors that are installed The engine must first be fully warmed through to a minimum temperature r= equired for closed loop operation. Attach the positive lead of a high imp= edance DC voltmeter to the Oxygen sensor output wire. This wire should re= main attached to the ECU computer. You will have to back probe the connec= tion or use a jumper wire to get access. The negative lead should be atta= ched to a good clean ground on the engine block or the case of the ECU. C= heap voltmeters will not give accurate results because they load down the= circuit and absorb the voltage that they are attempting to measure. A ac= ceptable value is 1,000,000 ohms/volt or more on the DC voltage. Generall= y digital multimeters/voltmeters can safely be used but ordinary analogu= e voltmeters/multimeters could both damage the sensor and give inaccurat= e results.(if any) non-powered analogue meters do. = Most late model cars use a heated 02 sensor. These have either two or th= ree 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 mak= e sure you won't wrap up any wires in the belts, etc. then start the engi= ne. You should run the engine above 2000 rpm for two minutes to warm the = O2 sensor and try to get into closed loop. The sensor showing several cro= ss counts per second indicates closed loop operation. It may help to rev = the engine between idle and about 3000 rpm several times. The computer recogn= ises the sensor as hot and active once there are several cross counts. Yo= u are looking for voltage to go above and below 0.45 volts. If you see le= ss than 0.2 and more than 0.7 volts and the value changes rapidly, you ar= e 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 stead= y 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 gasol= ine, 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 ext= ra fuel, the 02 sensor is usually good. If the voltage is steady high, cr= eate a vacuum leak. Try pulling the PCV valve out of it's hose and lettin= g 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 yo= u are not able to make a change either way, stop the engine, unhook the s= ensor 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 connectio= n, 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 carb= on 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 might = clean it off 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 02 sensors on the workbench. Use a high impedance DC voltmeter as above. Clamp the sensor in a vice, o= r use a pliers or vice-grips to hold it. Clamp your negative voltmeter le= ad to the case and the positive to the output wire of the sensor. 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 a= t 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 s= ee a drop to under 0.1 volt within 4 seconds. If not likely silicone foul= ed. If still OK, heat for two full minutes and watch for drops in voltage= =2E 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 sen= sor is good. Bear in mind that good or bad is relative, with port fuel in= jection needing faster information than carburettor systems. ANY 02 senso= r that will generate 0.9 volts or more when heated, and show 0.1 volts or= less within one second of flame removal, AND pass the two minute heat te= st is good regardless of age. When replacing a sensor, don't miss the op= portunity 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= =2E -.- -.-.- -.- -.- .................,,....... = Rick Kirchhof Austin, Texas I Experience is what you Domain: rick@xxx.org I get when you don't Bang path: . .. !cs.utexas.edu!peyote!~)~~~ms!rick I get what you want. - --------------C79FFB9E7CA1C7989CA7BEDF-- ------------------------------ From: Steve Ravet Date: Mon, 16 Nov 1998 11:12:45 -0600 Subject: Re: Upload Tom Sharpe wrote: > > Group, > > If someone will tell me how and where to put it...(no flames please), I > have a bin Browser I'd like to contribute to the web site........ but > how and where???? Left yourself wide open there... If you are using netscape for ftp, here is how to upload a file: First, enter the server name in the Location field like this: ftp://efi332.eng.ohio-state.edu Then, click on incoming. That's the only directory that will accept uploads Then, select "upload file" from the menu. Netscape will prompt you for the file to upload. Select it and off you go. most important: I try to maintain an index of the files in the ftp site. When you upload a file, send a note to the diy_efi list that has contains the filename that you uploaded and a description. That way I or anyone else can search for the filename in the archives and come up with a description. That especially applies to things like .bin files, where it's difficult to come up with an application just given the broadcast code. > > Regards Tom - -- Steve Ravet steve.ravet@xxx.com Advanced Risc Machines, Inc. www.arm.com ------------------------------ From: andy quaas Date: Mon, 16 Nov 1998 09:33:25 -0800 (PST) Subject: GM TBI to 4bbl intake Anybody seen an adaptor to fit a GM 2-bbl TBI unit onto a holley or Q-Jet intake? Andy Q _________________________________________________________ DO YOU YAHOO!? Get your free @xxx.com ------------------------------ From: Joe Boucher Date: Mon, 16 Nov 1998 12:01:39 -0600 Subject: Steering Wheel Switches I went to Las Vegas with the wife the last week of October. Went to the Sahara hotel where they have an interesting driving simultation using 24, 3/4 size Indy cars mounted on hydraulic rams, each in it's on booth in front of a big wide screen. You guessed it, you race against the other drivers. For $8 it was better than the simulators in the arcades. They give you a read out after you race with a traction circle and other info showing how you did. After looking at the info, I was less frustrated and wanted to go back, but the wife had another agenda. The transmission was semi-auto with the up and down buttons on the steering wheel. That made me think of the higher end cars in the late '80's. There seemed to be a contest to see who could mount the most buttons on the steering wheel. I think the Bonneville SEi had more than an F-16 cockpit. I know each button didn't have a seperate ring in the steering column, so how did the switch signal travel from the steering wheel to where ever it went? All my electronically limited mind can think of is either different resistances or capacitances or varying frequency signals. Am I close? Joe Boucher '70 RS/SS Camaro '81 TBI Suburban ------------------------------ From: Orin Eman Date: Mon, 16 Nov 1998 10:22:40 -0800 (PST) Subject: Re: Steering Wheel Switches > The transmission was semi-auto with the up and down buttons on the steering > wheel. That made me think of the higher end cars in the late '80's. There seemed > to be a contest to see who could mount the most buttons on the steering wheel. I > think the Bonneville SEi had more than an F-16 cockpit. I know each button didn't > have a seperate ring in the steering column, so how did the switch signal travel > from the steering wheel to where ever it went? All my electronically limited mind > can think of is either different resistances or capacitances or varying frequency > signals. I'd use a microcontroller and a serial protocol. Three wires (2 power, 1 data) at most, though you could get away with only two if you superimposed the data signal on the power lines! Orin. ------------------------------ From: "Bruce Plecan" Date: Mon, 16 Nov 1998 13:36:36 -0500 Subject: Re: GM TBI to 4bbl intake - -----Original Message----- From: andy quaas To: diy efi Date: Monday, November 16, 1998 1:25 PM Subject: GM TBI to 4bbl intake >Anybody seen an adaptor to fit a GM 2-bbl TBI unit onto a holley or >Q-Jet intake? GM used them on the early BBC, TBIs, and Holley at one time sold them. If dealer can't find them, while a PITA, the numbers were in the archives Bruce > >Andy Q > > > > >_________________________________________________________ >DO YOU YAHOO!? >Get your free @xxx.com > ------------------------------ From: "Bruce Plecan" Date: Mon, 16 Nov 1998 13:44:54 -0500 Subject: Re: Injector Impedance how low can i go... - -----Original Message----- From: Andrew F. Gunnesch To: diy_efi@xxx.edu> Date: Monday, November 16, 1998 11:42 AM Subject: Re: Injector Impedance how low can i go... >On Nov 16, 10:13pm, Richard Wakeling wrote: >> Subject: Re: Injector Impedance how low can i go... >> Hi Stuart, >> I recently discovered that the "808" seems to have the ability to >>drive a couple of low impedence injectors in peek and hold mode. >>There is provision already on the PCB to use the existing >>saturation injector driver in peek and hold mode by, >Any idea if this works for the '165 ECMs as well then? Since the 808 and 165 seem to be fairly similar beasts. > >This would really be a boon if you could take a 165 ECM and >convert it from using 8 saturation injectors to 8 peak-and-hold >injectors, no? Does anyone have any documentation to show where a Peak+Hold injector is "better" than a saturated?.. Yes, their operating times are fast (1-5msec.), but in anything other than SEFI, or very high rpm way bother?. But, if doing a "normal" TPI or v-8 say limited to 7,500 why bother?.. BTW, the S+H suggested times are 2-10msec. Cheers Bruce > ------------------------------ End of DIY_EFI Digest V3 #549 ***************************** To subscribe to DIY_EFI-Digest, send the command: subscribe diy_efi-digest in the body of a message to "Majordomo@xxx. A non-digest (direct mail) version of this list is also available; to subscribe to that instead, replace "diy_efi-digest" in the command above with "diy_efi".