Problems with Greddy A/F gauge
07-20-03, 09:57 AM
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Problems with Greddy A/F gauge
Got my Greddy A/F gauge installed. The sensor is installed just after the turn in the dp where it goes parallel with the ground. The gauge will not go out of the pre heating mode. Also, I triple checked the wiring and I am still getting the warning light blinking twice, then a pause. This means that there is a problem with the wiring somewhere. The gauge is really jumpy, all over the place. I am wondering if the sensor is bad or something. Sorry, this is kind of a bad description but can anybody help? Thanks.
07-20-03, 11:03 AM
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i'm getting that as well on my cheap autometer one...its not because your guage is messed up its because of our o2 sensor apparently...here's what i got
-Dan
Originally posted by ludeowner
If the more expensivce autometer gauge still gets readings from the stock sensor wont it still tell if whether you are rich (closed loop) or rich-lean-rich-lean...(open loop)?
That's about all the narrow band type A/F gauges do. When you are cruising or idling then if will cycle back and forth since the ECU is in open loop, but once you go WOT if always shows lean since the ECU goes to closed loop. The problem with this is the gauge wont tell you how rich you are. IIRC in an FD a good A/F ratio at WOT, high RPM is 10.5 or 11. But with the cheap gauges it could be possible for the gauge to show full rich when you could possibly be at an A/F ratio of 12 or leaner.
Bottom line, an A/F gauge that only reads rich lean is almost useless as a tuning tool. By the time that thing tells you that you are running lean at WOT it's probably too late. Why spend $170 for a autometer A/F gauge, when you could spend an extra hundred and just get a techedge WB setup?
If the more expensivce autometer gauge still gets readings from the stock sensor wont it still tell if whether you are rich (closed loop) or rich-lean-rich-lean...(open loop)?
That's about all the narrow band type A/F gauges do. When you are cruising or idling then if will cycle back and forth since the ECU is in open loop, but once you go WOT if always shows lean since the ECU goes to closed loop. The problem with this is the gauge wont tell you how rich you are. IIRC in an FD a good A/F ratio at WOT, high RPM is 10.5 or 11. But with the cheap gauges it could be possible for the gauge to show full rich when you could possibly be at an A/F ratio of 12 or leaner.
Bottom line, an A/F gauge that only reads rich lean is almost useless as a tuning tool. By the time that thing tells you that you are running lean at WOT it's probably too late. Why spend $170 for a autometer A/F gauge, when you could spend an extra hundred and just get a techedge WB setup?
07-20-03, 12:19 PM
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You got it. The factory O2 sensor is incapable of showing a correct reading on an a/f gauge. If you really want to know what your A/F ratio is while in the car, you need the FJO wideband O2.
07-21-03, 08:53 AM
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The greddy comes with it's own four wire O2 sensor. I would assume that it would have readings a little more accurate than bouncing all over the gauge?
Last edited by volley1; 07-21-03 at 09:22 AM.
07-21-03, 09:20 AM
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Originally posted by volley1
The greddy comes with it's own four wire O2 sensor. I would assume that it would have readings a little more accurate that bouncing all over the gauge?
The greddy comes with it's own four wire O2 sensor. I would assume that it would have readings a little more accurate that bouncing all over the gauge?
07-22-03, 08:25 AM
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Does anybody have this gauge? What setting did you set the gauge to? It has four different settings depending on if you are running a turbo or not. Thanks.
07-22-03, 10:05 AM
#7
A 4 wire O2 is no more accurate than the stock sensor. As was stated earlier if you want anything that is any more useful than a pretty cluster of blinking lights you will need to spend the money on a wide-band oxygen sensor.
Of course this does not help you get to the point where at least you have the pretty blinking lights working in their intended fashion.
Of course this does not help you get to the point where at least you have the pretty blinking lights working in their intended fashion.
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07-22-03, 10:09 AM
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I would disagree that the Greddy gauge/sensor is inaccurate. My mechanic has used one for years, and in fact, has completely tuned his car by using it. It's pretty accurate compared to the wideband on the dyno. He has been running 15 psi for 10 yrs/50k+ miles, including some time with a T-78 (on the same motor).
Sorry volley1, I don't know how to help you. Where did you buy the gauge from? If you got it from www.rx7.com, they will certainly help you out.
Sorry volley1, I don't know how to help you. Where did you buy the gauge from? If you got it from www.rx7.com, they will certainly help you out.
07-22-03, 10:19 AM
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Got it from Richsrotary on the forum. I will try the other settings and recheck the wiring I guess. If that doesn't work I may need to buy a new O2 sensor from Greddy. I hope it isn't screwed up. I think that there probably is a problem with the sensor because at first I had the signal from the Greddy sensor feeding the ecu the O2 readings. I ended up getting a warning light and the code was 17, I think, which is a problem with the O2 signal. I unplugged the stock location for the O2 sensor, had a oil drain plug in it, and bought a new O2 sensor from Autozone. I haven't had a check engine light since. So maybe the sensor is fried somehow or has a loose connection somewhere?
07-22-03, 11:46 AM
#10
Ex fd *****
The ECU is in CLOSED LOOP mod ANY TIME there is NO BOOST. In closed loop the a/f ratio will (and should) bounce from Rich to Lean very rapidly, it is the function of the closed loop operation. in CL the ECU rapidly adds fuel until it sees a Rich reading from the O2 sensor, at which point it rapidly cuts fuel until it sees a LEAN reading from O2 sensor, and then starts the LOOP over again adding fuel etc. etc.. This constant adjustment from lean to rich enshures that the AVERAGE a/f ratio is right in the center of the ideal range for best milage & lowest emissions.
Under Boost the ECU changes to a MAP/DutyCycle mapped mode and this is when you should see a constant relativly RICH reading on the A/F meter
At Idle the Exhaust will probably have so much Oxygen and be too cool give any useable reading from the O2 sensor (read below the leanest reading) on the A/F meter.
Under Boost the ECU changes to a MAP/DutyCycle mapped mode and this is when you should see a constant relativly RICH reading on the A/F meter
At Idle the Exhaust will probably have so much Oxygen and be too cool give any useable reading from the O2 sensor (read below the leanest reading) on the A/F meter.
07-22-03, 11:59 AM
#11
A quick google search I found this quote:
"One should note that GReddy, a highly regarded supplier of quality products, cautions strongly and repeatedly that one SHOULD NOT rely on their 4-wire sensor (one step down from a 5-wire true UEGO wideband sensor like the FJO) and associated Air/Fuel Ratio gauge for tuning purposes. They strongly recommend that a "laboratory spec" quality system be used. The FJO is an affordable system that provides the same level of accuracy as the so-called laboratory spec system. (See the GReddy Air/Fuel Ratio gauge owner's manual for specifics of this warning and other details on the GReddy system.)"
I do not have a Greddy air/fuel gauge manual to verify what it says, but I still wouldnt recommend tuning based on any narrow-band O2 sensor.
"One should note that GReddy, a highly regarded supplier of quality products, cautions strongly and repeatedly that one SHOULD NOT rely on their 4-wire sensor (one step down from a 5-wire true UEGO wideband sensor like the FJO) and associated Air/Fuel Ratio gauge for tuning purposes. They strongly recommend that a "laboratory spec" quality system be used. The FJO is an affordable system that provides the same level of accuracy as the so-called laboratory spec system. (See the GReddy Air/Fuel Ratio gauge owner's manual for specifics of this warning and other details on the GReddy system.)"
I do not have a Greddy air/fuel gauge manual to verify what it says, but I still wouldnt recommend tuning based on any narrow-band O2 sensor.
07-22-03, 12:22 PM
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In general, I would agree, Tom93R1. I was merely pointing out the fact that my mechanic has tuned his own engine (on the road, not on the dyno) with the Greddy A/F meter. He has had stock twins, a T-78, and now 99-spec twins on his streetported motor. The motor is still going strong with 10 yrs/50+k miles on it.
It IS possible to use this meter carefully to tune your car (obviously tuning to the ragged edge is out, but who wants to do that anyway?), and I think it would make a good gauge for monitoring.
All that said, I will be going with the FJO wideband due to the datalogging and other capabilities, as well as the slightly increased accuracy.
It IS possible to use this meter carefully to tune your car (obviously tuning to the ragged edge is out, but who wants to do that anyway?), and I think it would make a good gauge for monitoring.
All that said, I will be going with the FJO wideband due to the datalogging and other capabilities, as well as the slightly increased accuracy.
07-22-03, 12:42 PM
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I agree also that the FJO is the way to go when it comes to tuning. I just want to make sure the thing is working the right way. If it never warms up and is always in the warm up mode, then there must be something wrong, right? So at idle and cruising the gauge should bounce all over the place and then be steady at WOT? As soon as I hit the gas it jumps to 8.0 a/f pinned.
07-22-03, 04:59 PM
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Originally posted by ludeowner
...but once you go WOT if always shows lean since the ECU goes to closed loop.
...but once you go WOT if always shows lean since the ECU goes to closed loop.
I meant to say that when you go WOT that it will always show RICH. And also I think I got closed loop and open loop mixed up. Open loop being WOT conditions, and closed loop meaning data is being taken from the ECU. (I think that's right)
07-22-03, 11:38 PM
#15
I have the Greddy A/F on my TII and have since it was near stock to way modded.
The O2 sensor is mounted in stock location ~4" from the turbo. This worked fine when near stock, heated up quickly and never overheated.
A/f was all over the place at anything but full throttle- this is how the stock ECU does things.
Now that I have a large streetport and T4 "O" trim wheel clipped 15 deg and 3 1/2" turbo back the O2 sensor overheats too easily in this location.
W/ the Haltech, the AF is rock steady where ever you set it (if your correction factors are on). I set it for 14.7 at cruise and it stays right there. It responds exactly as it should to map adjustments. Of course, I have it tuned conservatively for boost.
I am impressed so far. I will check and adjust it against the dyno wideband when I get my set-up dynoed.
The O2 sensor is mounted in stock location ~4" from the turbo. This worked fine when near stock, heated up quickly and never overheated.
A/f was all over the place at anything but full throttle- this is how the stock ECU does things.
Now that I have a large streetport and T4 "O" trim wheel clipped 15 deg and 3 1/2" turbo back the O2 sensor overheats too easily in this location.
W/ the Haltech, the AF is rock steady where ever you set it (if your correction factors are on). I set it for 14.7 at cruise and it stays right there. It responds exactly as it should to map adjustments. Of course, I have it tuned conservatively for boost.
I am impressed so far. I will check and adjust it against the dyno wideband when I get my set-up dynoed.
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