I want an Air Fuel Ratio real-time Monitor!
Jun 20, 2006 | 02:23 PM
#1
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Joined: May 2006
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From: Morgan Hill, Ca
I want an Air Fuel Ratio real-time Monitor!
Has anyone here tried sorting out tuning problems with an air fuel ratio monitor.
Based on the mpg poll I set up, a lot of us are running lower mpg than we should. There is a big enough sample at this point (I set the poll limit to 60 days, but its already above 40 votes) to conclude that our 3vze engines should be running at or above 18mpg sans leadfoot.
Which implies strongly that the rest of us running 13-14-15 have something not correct, despite clean emissions and good performance.
It occured to me this morning, that the ideal way to troubleshoot would be some kind of monitor that measures air/fuel ratio at the exhaust manifold, or for the V6, at the point the exhaust is conjoined, but before any processing done by the cat etc.
So I googled <air fuel ratio monitor> (try it), not expecting to get much. Well it turns out there is a ton of experience on the subject, from amateur tuners to hard-core race types.
The NGK article/ad is a good example: http://www.ngk.com/afx/default.asp?KID=3169#
After reading some user experience, such as: http://www.jetlink.net/~okayfine/su/airfuel.html it became clear that that is exactly what the O2 sensor is intended to provide to the ECM on our trucks... :pat:
So replacing and keeping the O2 sensor in good condition is critical. (duhhh)
But over and above that, how cool would it be to have a real-time gauge to keep an eye on your driving conditions. The savings in mpg and cats alone would pay for even the more expensive NGK solution. The one article above claims you can buy gauges for $30.
So what do you all think? I'll bet there are people on here that have done just this, but a search doesn't pick it up. So the advanced cases (imho) are just not talking to rest of us.
Based on the mpg poll I set up, a lot of us are running lower mpg than we should. There is a big enough sample at this point (I set the poll limit to 60 days, but its already above 40 votes) to conclude that our 3vze engines should be running at or above 18mpg sans leadfoot.
Which implies strongly that the rest of us running 13-14-15 have something not correct, despite clean emissions and good performance.
It occured to me this morning, that the ideal way to troubleshoot would be some kind of monitor that measures air/fuel ratio at the exhaust manifold, or for the V6, at the point the exhaust is conjoined, but before any processing done by the cat etc.
So I googled <air fuel ratio monitor> (try it), not expecting to get much. Well it turns out there is a ton of experience on the subject, from amateur tuners to hard-core race types.
The NGK article/ad is a good example: http://www.ngk.com/afx/default.asp?KID=3169#
After reading some user experience, such as: http://www.jetlink.net/~okayfine/su/airfuel.html it became clear that that is exactly what the O2 sensor is intended to provide to the ECM on our trucks... :pat:
So replacing and keeping the O2 sensor in good condition is critical. (duhhh)
But over and above that, how cool would it be to have a real-time gauge to keep an eye on your driving conditions. The savings in mpg and cats alone would pay for even the more expensive NGK solution. The one article above claims you can buy gauges for $30.
So what do you all think? I'll bet there are people on here that have done just this, but a search doesn't pick it up. So the advanced cases (imho) are just not talking to rest of us.
Jun 20, 2006 | 02:31 PM
#2
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Joined: Mar 2004
Posts: 511
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From: Salem,Oregon
You really need a wideband unit to get accurate readings during throttle movement. I have made several changes to my truck trying to lean the mixture and improve mileage. Once I get done with this tank of fuel I will know if my work paid off. I cut my warm up fuel consumption down considerably as well.
Jun 20, 2006 | 02:55 PM
#3
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Joined: Apr 2006
Posts: 1,368
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From: Vancleave, Mississippi
somewhere in my haynes manual says to turn the screw on top of the throttle body all the way in and then 4.5 turns out...i got about 285 miles on my last tank when before my engine swap, intake clean, and new mass air flow meter i was getting less than 200 miles per tank!
Jun 20, 2006 | 04:35 PM
#4
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Joined: Jan 2006
Posts: 183
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From: Southern California
take a look and see if this type of unit will help. Pricey though very capable
http://cgi.ebay.com/ebaymotors/Aerof...QQcmdZViewItem
http://cgi.ebay.com/ebaymotors/Aerof...QQcmdZViewItem
Jun 20, 2006 | 05:13 PM
#5
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Joined: Jun 2006
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Originally Posted by rdharper
Has anyone here tried sorting out tuning problems with an air fuel ratio monitor.
Based on the mpg poll I set up, a lot of us are running lower mpg than we should. There is a big enough sample at this point (I set the poll limit to 60 days, but its already above 40 votes) to conclude that our 3vze engines should be running at or above 18mpg sans leadfoot.
Which implies strongly that the rest of us running 13-14-15 have something not correct, despite clean emissions and good performance.
It occured to me this morning, that the ideal way to troubleshoot would be some kind of monitor that measures air/fuel ratio at the exhaust manifold, or for the V6, at the point the exhaust is conjoined, but before any processing done by the cat etc.
So I googled <air fuel ratio monitor> (try it), not expecting to get much. Well it turns out there is a ton of experience on the subject, from amateur tuners to hard-core race types.
The NGK article/ad is a good example: http://www.ngk.com/afx/default.asp?KID=3169#
After reading some user experience, such as: http://www.jetlink.net/~okayfine/su/airfuel.html it became clear that that is exactly what the O2 sensor is intended to provide to the ECM on our trucks... :pat:
So replacing and keeping the O2 sensor in good condition is critical. (duhhh)
But over and above that, how cool would it be to have a real-time gauge to keep an eye on your driving conditions. The savings in mpg and cats alone would pay for even the more expensive NGK solution. The one article above claims you can buy gauges for $30.
So what do you all think? I'll bet there are people on here that have done just this, but a search doesn't pick it up. So the advanced cases (imho) are just not talking to rest of us.
Based on the mpg poll I set up, a lot of us are running lower mpg than we should. There is a big enough sample at this point (I set the poll limit to 60 days, but its already above 40 votes) to conclude that our 3vze engines should be running at or above 18mpg sans leadfoot.
Which implies strongly that the rest of us running 13-14-15 have something not correct, despite clean emissions and good performance.
It occured to me this morning, that the ideal way to troubleshoot would be some kind of monitor that measures air/fuel ratio at the exhaust manifold, or for the V6, at the point the exhaust is conjoined, but before any processing done by the cat etc.
So I googled <air fuel ratio monitor> (try it), not expecting to get much. Well it turns out there is a ton of experience on the subject, from amateur tuners to hard-core race types.
The NGK article/ad is a good example: http://www.ngk.com/afx/default.asp?KID=3169#
After reading some user experience, such as: http://www.jetlink.net/~okayfine/su/airfuel.html it became clear that that is exactly what the O2 sensor is intended to provide to the ECM on our trucks... :pat:
So replacing and keeping the O2 sensor in good condition is critical. (duhhh)
But over and above that, how cool would it be to have a real-time gauge to keep an eye on your driving conditions. The savings in mpg and cats alone would pay for even the more expensive NGK solution. The one article above claims you can buy gauges for $30.
So what do you all think? I'll bet there are people on here that have done just this, but a search doesn't pick it up. So the advanced cases (imho) are just not talking to rest of us.
Jun 20, 2006 | 06:19 PM
#6
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Joined: Feb 2006
Posts: 490
Likes: 2
Originally Posted by spirtlanimilbus
install a 2nd wideband o2 sensor & bung right next to your stock sensor then go buy an autometer air fuel gauge... i had one on my b2200 with a weber carb and it works great for tuning... can be done with a universal wideband sensor and the gauge is under 100 bux..
I'm not tryin' to be facetious-- just askin' a question.
Thanx
Mike in AR
Jun 20, 2006 | 06:25 PM
#7
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Joined: Aug 2005
Posts: 2,419
Likes: 8
From: Peoria IL
I thought the advanced systems fed the O2 sensor voltage through the computer and then output a second V. then you could manually tweek the V and watch the result thus fooling the computer into doing what YOU want.
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Jun 20, 2006 | 06:28 PM
#8
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Joined: Jun 2006
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MEGA SQUIRT.........SCREW OBD , IVE BEEN LOOKING IN TO ONE OF THESE FOR A LONG ASS TIME..
http://www.megasquirt.info/index.html
http://www.megasquirt.info/index.html
Jun 20, 2006 | 10:32 PM
#9
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Joined: Dec 2002
Posts: 9,048
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From: Seattleish, WA
Hey Richard....
Ummm.. a bunch of babble, in no particular order.
Yes, the O2 sensor in front of the cat is the one that feeds the ECU. And yes the ECU uses that information to adjust the A/FR. But...
While the engine's in closed loop (basically when you're not stomping on the pedal) then the ECU will always make the required adjustments to get the A/FR to 14.7:1 (known as "Stoich" which is shorthand for "Stoichiometry conditions") which is the "optimum" point of fuel efficiency for gasoline.
There is little that you can do to change this over the long term. Some of us run piggyback computers (e.g., SplitSecond FTC or Perfect Power SMT) which allow us to adjust the fuel and timing maps, but the fuel side is a short term bandaid. The ECU will _always_ fight the piggyback and eventually push the A/FR back to 14.7:1.
How long will this take? Well, the jury will be out on that one for a while, but I can notice a difference in my rig after 1000 miles or less. You can clear the "chase" effect by reseting the ECU (there's a fuse under the hood, or pull a battery cable for a minute(ish)).
Buying into a wideband is NOT the answer here. Yes, it will help you tune, but again, any tuning you do in closed loop will be fought by the ECU over time.
Buying into an AF/R meter is an okay idea, (and yes, you can find them pretty cheap) but again, you'll find that the ones with ballistics corrections (i.e., they smooth out the swing of a narrow band sensor) will do a good job of showing 14.7:1 most of the time. The "non-most of the time" will come at WOT, or during "idle cut" which happens when you take your foot off the gas.
Spirt's pointer to the Megasquirt is an excellent idea, but it's not a project for the faint of heart. I've been wanting to do it for a while, but there's a lot more involved than you would think. The Megasquirt is a complete replacement _fuel_ controller - you can set it to do anything you want. The Megasquirt II is a CPU upgrade that now has enough bandwidth to handle timing control as well.
There are a LOT of issues in going this route. It is NOT a plug & play system.
I think that's enough babble for now... Lemme know if you have more questions.
(and yes, I know you have questions pending in the other thread!
)
Ummm.. a bunch of babble, in no particular order.
Yes, the O2 sensor in front of the cat is the one that feeds the ECU. And yes the ECU uses that information to adjust the A/FR. But...
While the engine's in closed loop (basically when you're not stomping on the pedal) then the ECU will always make the required adjustments to get the A/FR to 14.7:1 (known as "Stoich" which is shorthand for "Stoichiometry conditions") which is the "optimum" point of fuel efficiency for gasoline.
There is little that you can do to change this over the long term. Some of us run piggyback computers (e.g., SplitSecond FTC or Perfect Power SMT) which allow us to adjust the fuel and timing maps, but the fuel side is a short term bandaid. The ECU will _always_ fight the piggyback and eventually push the A/FR back to 14.7:1.
How long will this take? Well, the jury will be out on that one for a while, but I can notice a difference in my rig after 1000 miles or less. You can clear the "chase" effect by reseting the ECU (there's a fuse under the hood, or pull a battery cable for a minute(ish)).
Buying into a wideband is NOT the answer here. Yes, it will help you tune, but again, any tuning you do in closed loop will be fought by the ECU over time.
Buying into an AF/R meter is an okay idea, (and yes, you can find them pretty cheap) but again, you'll find that the ones with ballistics corrections (i.e., they smooth out the swing of a narrow band sensor) will do a good job of showing 14.7:1 most of the time. The "non-most of the time" will come at WOT, or during "idle cut" which happens when you take your foot off the gas.
Spirt's pointer to the Megasquirt is an excellent idea, but it's not a project for the faint of heart. I've been wanting to do it for a while, but there's a lot more involved than you would think. The Megasquirt is a complete replacement _fuel_ controller - you can set it to do anything you want. The Megasquirt II is a CPU upgrade that now has enough bandwidth to handle timing control as well.
There are a LOT of issues in going this route. It is NOT a plug & play system.
I think that's enough babble for now... Lemme know if you have more questions.
(and yes, I know you have questions pending in the other thread!
)
Jun 21, 2006 | 03:20 AM
#10
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Joined: Mar 2004
Posts: 511
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From: Salem,Oregon
The 14.7:1 that the stock ECU strives to maintain is not the problem, heck if it would do it all the time that would be great for us normally aspirated folks. Its after you do headers,cams,intake manifolds and other assorted stuff that you need some regulation to the AFR during rapid acceleration or when you get so far from the stock configuration that the ECU wont correct for it.
When my mileage is down to 12-13 mpg running 33x10.5's on 5.29's we know we have a mixture problem. Every thing on my engine has been rebuilt and works perfectly but I have taken it so far from its factory state of tune that I need some correction.
I built a hybrid AFM using a 7m AFM body and flapper and the stock 3.0 AFM board in an attempt to lean things out a bit and open the restriction point up a bit. I have been running it for about 3 or 4 days but I don't have any mileage numbers as of yet. The truck seems to run a bit better (not that it ran badly before) but I really need an AF meter preferably a wide-band meter with data logging (I'm thinking r-300 or dynojet in the next month or so) to give me the wot info and not just the cruise info. When I set up the spring resistance on the hybrid AFM I plotted resistance points at different RPMs using an unmolested stock AFM then setting the flapper spring tension and mixture control using those resistance points at given RPM's.
In an attempt to cut fuel consumption I have done what would be considered a reverse ECT mod using a 10k pot/switch combo in parallel with the water temp sensor to reduce my cold start enrichment by tricking the ECU into thinking the engine is warmer than it really is. I think most of the problem after headers,porting and other intake mods is the operating temp of the 3.0 drops considerably. Unless I'm working the motor on a trail or on the freeway it never really seemed to come off warm up enrichment. This reduction in temp will probably prolong head gasket life as well as make the motor more reliable once the enrichment is corrected.
Once I get a big picture from the Wide-band meter I may just opt for the mega-squirt II system. If I don't get burned out on the 3.0 I plan on a remote Turbo system just to see if it can be done successfully. The hard part is deciding between things like dual cases/solid axle or Wide-band meter/Mega-squirt system.
I also have an 02 Maxima with the VQ35. After reading what some of the guys have done on the Maxima forums it seems the maxima really benefits from an AFC2 or other piggyback item after headers. Headers on the VQ35 will cause it to run so rich that often times people see no performance benefit to installing them (sound familiar???) until they re-tune the fuel system and realise the 20+ HP gained after the AF ratio is corrected. I suspect the the Toyota 3.0 suffers from a similar problem after a header install.
OK that's enough rambling for now...
When my mileage is down to 12-13 mpg running 33x10.5's on 5.29's we know we have a mixture problem. Every thing on my engine has been rebuilt and works perfectly but I have taken it so far from its factory state of tune that I need some correction.
I built a hybrid AFM using a 7m AFM body and flapper and the stock 3.0 AFM board in an attempt to lean things out a bit and open the restriction point up a bit. I have been running it for about 3 or 4 days but I don't have any mileage numbers as of yet. The truck seems to run a bit better (not that it ran badly before) but I really need an AF meter preferably a wide-band meter with data logging (I'm thinking r-300 or dynojet in the next month or so) to give me the wot info and not just the cruise info. When I set up the spring resistance on the hybrid AFM I plotted resistance points at different RPMs using an unmolested stock AFM then setting the flapper spring tension and mixture control using those resistance points at given RPM's.
In an attempt to cut fuel consumption I have done what would be considered a reverse ECT mod using a 10k pot/switch combo in parallel with the water temp sensor to reduce my cold start enrichment by tricking the ECU into thinking the engine is warmer than it really is. I think most of the problem after headers,porting and other intake mods is the operating temp of the 3.0 drops considerably. Unless I'm working the motor on a trail or on the freeway it never really seemed to come off warm up enrichment. This reduction in temp will probably prolong head gasket life as well as make the motor more reliable once the enrichment is corrected.
Once I get a big picture from the Wide-band meter I may just opt for the mega-squirt II system. If I don't get burned out on the 3.0 I plan on a remote Turbo system just to see if it can be done successfully. The hard part is deciding between things like dual cases/solid axle or Wide-band meter/Mega-squirt system.
I also have an 02 Maxima with the VQ35. After reading what some of the guys have done on the Maxima forums it seems the maxima really benefits from an AFC2 or other piggyback item after headers. Headers on the VQ35 will cause it to run so rich that often times people see no performance benefit to installing them (sound familiar???) until they re-tune the fuel system and realise the 20+ HP gained after the AF ratio is corrected. I suspect the the Toyota 3.0 suffers from a similar problem after a header install.
OK that's enough rambling for now...
Jun 21, 2006 | 04:28 AM
#11
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Joined: Nov 2002
Posts: 10,666
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From: Oklahoma State
Jun 21, 2006 | 05:24 AM
#12
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Joined: Dec 2002
Posts: 9,048
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From: Seattleish, WA
This is fun...
http://www.bobblick.com/techref/proj...sim/o2sim.html
The lead-in is here:
http://www.bobblick.com/techref/proj.../o2sensor.html
Bottom line, it's an oscillator used to fake the O2 sensor signal so that you can adjust the closed loop tuning. It _replaces_ the O2 sensor, not just pggybacks it.
http://www.bobblick.com/techref/proj...sim/o2sim.html
The lead-in is here:
http://www.bobblick.com/techref/proj.../o2sensor.html
Bottom line, it's an oscillator used to fake the O2 sensor signal so that you can adjust the closed loop tuning. It _replaces_ the O2 sensor, not just pggybacks it.
Last edited by midiwall; Jun 21, 2006 at 05:28 AM.
Oct 16, 2006 | 07:31 AM
#16
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Joined: Apr 2003
Posts: 1,579
Likes: 0
From: Raleigh NC
cheap A/F gauges are a waste of time, if it doesn't use a wideband O2 sensor (which costs $100 by itself) you aren't getting any real reading anyway. My wideband setup:
The Innovate “Standalone Gauge Kit” comes complete with the NEW! LC-1 Wideband Controller, NEW! XD-1 Programmable Digital Gauge, Bosch 5-wire Wideband 02 Sensor, Bung/Plug Kit, Software CD, and owners manual.
The LC-1 is a complete wideband controller built in to a sealed cable. It features the same award-winning patented digital measurement principal found in the LM-1, and includes digital input, output, and 2 programmable analog outputs.
The Innovate XD-1 dash-mountable Digital Gauge features programmable LED colors and remote control button to start and stop LM-1 log sessions or initiate calibration.
Cost: $400 plus shipping
The Innovate “Standalone Gauge Kit” comes complete with the NEW! LC-1 Wideband Controller, NEW! XD-1 Programmable Digital Gauge, Bosch 5-wire Wideband 02 Sensor, Bung/Plug Kit, Software CD, and owners manual.
The LC-1 is a complete wideband controller built in to a sealed cable. It features the same award-winning patented digital measurement principal found in the LM-1, and includes digital input, output, and 2 programmable analog outputs.
The Innovate XD-1 dash-mountable Digital Gauge features programmable LED colors and remote control button to start and stop LM-1 log sessions or initiate calibration.
Cost: $400 plus shipping
Oct 16, 2006 | 07:39 AM
#17
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Joined: Jun 2006
Posts: 1,825
Likes: 2
From: austin, tx
My comments:
A basic 02 gauge would serve some function.. You should see the ECU "dither" the mixture at fixed throttle positions.. That is, it should switch from lean/rich quickly at cruise, etc. If it's not dithering, you've got a problem.
A wideband 02 is certainly more useful, although more expensive. I don't know what you're going to gain out of it with a stock ECU though - things like acceleration enrichment, warm-up enrichment, etc they're all pre-programmed into your ECU. Sure, you could setup a wideband and work to fool the ECU, but at that point you're spending a lot more money and effort into something that might get you a marginal gain.
I do megasquirt with the 22re-series. It's a great system. It's not for the electrically faint of heart, however, unless someone comes up with a "plug and play" type system for the 3.0L V6.
The OBD-II monitor is going to work with late 1995 and newer cars/trucks. OBD-I was too "non-standardized" to work well with a generic system.
Want better mileage? Do a swap (3RZ) or go turbo with a fully tunable ECU... The 3.0L is a relatively reliable motor, but it's expensive, it doesn't put out a lot of power, and it's really not efficient..
Oct 16, 2006 | 09:31 AM
#18
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Joined: Nov 2002
Posts: 10,666
Likes: 5
From: Oklahoma State
After running with my wideband sensor and OBDII readout for a while now, I think the reason the 3.0 gets such bad fuel economy is it must be going into open loop all the time. The lack of power means people go to WOT all the time which sends the ECU into open loop where it will run rich to protect the engine.
Oct 16, 2006 | 09:59 AM
#19
Registered User
Joined: Feb 2003
Posts: 3,689
Likes: 4
From: Sarasota, FL
Agreed and the injector batch firing during low to mid throttle ranges and the high stall TC from toyota OEM cant help fuel economy either...
Last edited by Bumpin' Yota; Oct 16, 2006 at 10:07 AM.
Oct 16, 2006 | 10:04 AM
#20
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Joined: Dec 2004
Posts: 614
Likes: 1
From: Greenville, SC
From what I can tell watching the Autometer gauge and 6 channel EGT the computer will NOT go open loop below 3000rpm. Which is probably why all the 3VZEs display a surge of power right at 3k when accellerating.
You can watch this happen on the gauge, it'll be lean, lean, lean, then right at 3k it goes rich and you feel the surge in the seat of the pants.
When in cruise it occilates pretty hard.
I suspect part of the problem is the computer is just too slow to keep up.
For standalone wideband monitoring Datona Twin Tech has the WEGO unit which are very well liked by Harley crotch rocket tuners.
My next upgrade for the vrod is their VRFI2 which has a wideband in each exhaust and self tuning computer. The guys who have done this are all reporting large improvements in throttle response and mileage (compared to Powercommanders and other piggyback tuners.)
A lot of people have 'talked' about tuners for the 3VZE, but I don't know of anyone who's actually succeded.
You can watch this happen on the gauge, it'll be lean, lean, lean, then right at 3k it goes rich and you feel the surge in the seat of the pants.
When in cruise it occilates pretty hard.
I suspect part of the problem is the computer is just too slow to keep up.
For standalone wideband monitoring Datona Twin Tech has the WEGO unit which are very well liked by Harley crotch rocket tuners.
My next upgrade for the vrod is their VRFI2 which has a wideband in each exhaust and self tuning computer. The guys who have done this are all reporting large improvements in throttle response and mileage (compared to Powercommanders and other piggyback tuners.)
A lot of people have 'talked' about tuners for the 3VZE, but I don't know of anyone who's actually succeded.
