Microtech Idle afr
08-13-09, 11:54 PM
#1
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Thread Starter
Idle afr
What exactly is involved in adjusting my idle afr for my tii? My car is idling rough and very rich, and I am trying to pass the smog test. I ran the smog test with a cat (no airpump) and some methyl hydrate in the gas tank, but my car managed to pull a 1500ppm (max allowable is 328ppm) for hydrocarbons, and the carbon monoxide was slightly over the max allowable value. Any help is appreciated, thanks.
08-16-09, 10:13 AM
#6
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I'm going to reply to you PM here so the answer will benefit everyone. Hope that's alright...
It may be difficult to get an emissions friendly idle without some way of measuring AFR. But, you can try.
Get the car fully warmed up and then make sure that the idle is steady enough. Begin pulling fuel. You will notice that RPM will increase, as will vacuum. Continue slowly pulling fuel from the current load bin and slightly from the surrounding bins. The best idle is where the engine is smoothest and vacuum is greatest. Most emissions tests will want a factory idle RPM, which for the RX-7 is 750RPM +- 50. You may need to physically adjust the hard idle screw while you are making fuel changes. It often helps to give it some timing as well. I tend to idle these cars around 15 degrees.
It helps to have a slightly richer bin on overrun (below idle speed) to "catch" the engine if it attempts to stall.
No idea. Most tuners will idle engines ridiculously rich for some reason. It think it makes their job easier and masks a poor tune. The engine should idle well around 13.5:1. Maybe a little richer if it is unsteady or you find RPM dropping with electrical loads.
It takes a considerable amount of time to tune a car properly, but a whole day just to make it pass an idle test seems a little excessive.
If you have the laptop adapter, you can save your map onto the adapter. But unlike other ECUs, the Microtech won't let you save maps to disk or edit them offline.
Hey Aaron, thanks for the reply on my thread. I am new to tuning on microtech and I just want to know exactly what is involved in adjusting the afr of my car at idle. To answer your question, I don't have a way to look at the afr values for my car.
Get the car fully warmed up and then make sure that the idle is steady enough. Begin pulling fuel. You will notice that RPM will increase, as will vacuum. Continue slowly pulling fuel from the current load bin and slightly from the surrounding bins. The best idle is where the engine is smoothest and vacuum is greatest. Most emissions tests will want a factory idle RPM, which for the RX-7 is 750RPM +- 50. You may need to physically adjust the hard idle screw while you are making fuel changes. It often helps to give it some timing as well. I tend to idle these cars around 15 degrees.
I am trying to figure out why my afr gauge isn't getting a signal. Anyway, the gauge is hooked up to a narrowband o2 sensor. I was talking to a guy at a local shop, and he mentioned stuff about having to raise the idle and having to do a bunch of stuff because the car might stall out while taking the smog test, which obviously won't do me any good.
Also, is there any reason why the car would have to be tuned rich so it would stay running at idle?
I'm just trying to save some money because that shop wants to keep my car for the whole day to lean the idle out, pass it through aircare (at my expense) and tune it back. Aren't I able to just get the maps off them and load it up on my ecu? If worst comes to worse, I will just have to take my car to the shop. I just don't want to be taken advantage of hah. Hope to hear from you soon. Thanks.
If you have the laptop adapter, you can save your map onto the adapter. But unlike other ECUs, the Microtech won't let you save maps to disk or edit them offline.
08-16-09, 12:58 PM
#7
Senior Member
Thread Starter
Thanks aaron, if I hit any more speed bumps I'll let you know. Rx72c is helping me with the idle map, so hopefully just leaning out the idle mixture will do the trick. One more question, since that microtech adaptor also stores your maps from what I can understand, will it be fine if I remove it?
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08-18-09, 04:09 PM
#9
I noticed you said you should be able to get it to idle at 13.5:1.
Their is a not a chance in hell with microtech to get a good idle at that afr mixture.
As soon as you switch if off and restart it it will just stall. the afterstart feature on the microtech only goes for 5 seconds.
Thats why most microtechs are setup for 11.7-12:1 to cover up for all the wholes in the microtech system. it is not laziness thing, not on my part anyway.
Their is a not a chance in hell with microtech to get a good idle at that afr mixture.
As soon as you switch if off and restart it it will just stall. the afterstart feature on the microtech only goes for 5 seconds.
Thats why most microtechs are setup for 11.7-12:1 to cover up for all the wholes in the microtech system. it is not laziness thing, not on my part anyway.
08-20-09, 09:26 AM
#11
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My car idles fine at 13.5.
The limited configuration of the ASE is one of the reasons the Microtech is not the best ECU choice. I agree, it is harder to get a decent startup with such a lean idle. I find the only real time it is an issue is on certain hot starts. It may want to stall but a quick blip of the throttle will take care of that. That to me is an acceptable compromise compared to a stinky, plug fouling and fuel wasting idle. Adding a bit of timing dramatically improves a leaner idle, as well as a bit more split. But once again, the limiting factor is the Microtechs poor timing maps.
All the Megasquirt cars I do will start up and idle happily at 13.5. Using the BAC valve to regulate idle speed in closed loop makes the car start and idle better then stock.
The limited configuration of the ASE is one of the reasons the Microtech is not the best ECU choice. I agree, it is harder to get a decent startup with such a lean idle. I find the only real time it is an issue is on certain hot starts. It may want to stall but a quick blip of the throttle will take care of that. That to me is an acceptable compromise compared to a stinky, plug fouling and fuel wasting idle. Adding a bit of timing dramatically improves a leaner idle, as well as a bit more split. But once again, the limiting factor is the Microtechs poor timing maps.
All the Megasquirt cars I do will start up and idle happily at 13.5. Using the BAC valve to regulate idle speed in closed loop makes the car start and idle better then stock.
08-20-09, 06:41 PM
#12
13.5:1
I'm going to reply to you PM here so the answer will benefit everyone. Hope that's alright...
It may be difficult to get an emissions friendly idle without some way of measuring AFR. But, you can try.
Get the car fully warmed up and then make sure that the idle is steady enough. Begin pulling fuel. You will notice that RPM will increase, as will vacuum. Continue slowly pulling fuel from the current load bin and slightly from the surrounding bins. The best idle is where the engine is smoothest and vacuum is greatest. Most emissions tests will want a factory idle RPM, which for the RX-7 is 750RPM +- 50. You may need to physically adjust the hard idle screw while you are making fuel changes. It often helps to give it some timing as well. I tend to idle these cars around 15 degrees.
It helps to have a slightly richer bin on overrun (below idle speed) to "catch" the engine if it attempts to stall.
No idea. Most tuners will idle engines ridiculously rich for some reason. It think it makes their job easier and masks a poor tune. The engine should idle well around 13.5:1. Maybe a little richer if it is unsteady or you find RPM dropping with electrical loads.
It takes a considerable amount of time to tune a car properly, but a whole day just to make it pass an idle test seems a little excessive.
If you have the laptop adapter, you can save your map onto the adapter. But unlike other ECUs, the Microtech won't let you save maps to disk or edit them offline.
It may be difficult to get an emissions friendly idle without some way of measuring AFR. But, you can try.
Get the car fully warmed up and then make sure that the idle is steady enough. Begin pulling fuel. You will notice that RPM will increase, as will vacuum. Continue slowly pulling fuel from the current load bin and slightly from the surrounding bins. The best idle is where the engine is smoothest and vacuum is greatest. Most emissions tests will want a factory idle RPM, which for the RX-7 is 750RPM +- 50. You may need to physically adjust the hard idle screw while you are making fuel changes. It often helps to give it some timing as well. I tend to idle these cars around 15 degrees.
It helps to have a slightly richer bin on overrun (below idle speed) to "catch" the engine if it attempts to stall.
No idea. Most tuners will idle engines ridiculously rich for some reason. It think it makes their job easier and masks a poor tune. The engine should idle well around 13.5:1. Maybe a little richer if it is unsteady or you find RPM dropping with electrical loads.
It takes a considerable amount of time to tune a car properly, but a whole day just to make it pass an idle test seems a little excessive.
If you have the laptop adapter, you can save your map onto the adapter. But unlike other ECUs, the Microtech won't let you save maps to disk or edit them offline.
I will love to have my bridgeport idle at 13.5:1 so i can save some fuel.Can you share your idle map?
08-21-09, 08:51 AM
#13
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My idle map is nothing special. I'm using the matrix table with different sized injectors so I doubt it would be much help to you. But I can post a screen shot if you wish.
Dial in more timing then people recommend. Idle around 15-18 degrees with 15 degrees of split and you will find a dramatic improvement.
Dial in more timing then people recommend. Idle around 15-18 degrees with 15 degrees of split and you will find a dramatic improvement.
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Phtmaz (07-08-21)
08-23-09, 03:06 PM
#15
Senior Member
Thread Starter
So the adaptor is just for saving extra maps that you want to keep, not the ones currently being used by the ecu when driving around? I can drive around with the adaptor unhooked and a map is programmed into the ecu itself, not only the adaptor, correct? By the way, I will have my idle map posted soon for those willing to help.
09-04-09, 04:55 PM
#20
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Thread Starter
My car just passed aircare with flying colors! One problem though, my engine seems to dip down to maybe as low as 500rpm and almost dies when I first start my car. I have to give the car a bit of gas to get it to idle normally. Also, my car does the same thing driving when I disengage the clutch to coast, letting the rpm drop. I have to ease off the throttle to avoid this. Is this caused by a rich afr?
09-05-09, 10:58 AM
#21
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Richen up the bin to the left of you idle a bin a little bit.
Also bump the idle timing slightly in that same bin.
Try increasing the after start percent a little to solve the startup issue and make sure that with the now leaner idle, you don't need to increase the cold start enrichment.
Also bump the idle timing slightly in that same bin.
Try increasing the after start percent a little to solve the startup issue and make sure that with the now leaner idle, you don't need to increase the cold start enrichment.
09-05-09, 01:39 PM
#22
Senior Member
Thread Starter
Hm, I'm having trouble connecting to my ecu. Is your computer supposed to show that you are connected as soon as you plug in the computer and switch the ignition to on? btw, does the free software from microtechefi.com work well?
09-05-09, 09:05 PM
#24
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Thread Starter
I'll find a way to connect to the ecu and I'll show you guys the idle map. I don't feel like paying for a rebuild if you know what I mean :p. I'm very paranoid about the car running rich, maybe I should invest in a wideband o2 sensor for peace of mind... Would I be able to just run the wideband sensor to a gauge without having to connect it to the ecu as well? My stock o2 sensor is connected to the ecu and my afr gauge (not getting any signal from the sensor). But anyway, I don't think my ecu is meant to run a wideband.
I'll keep you guys updated, I'll be needing a lot of advice and help.
I'll keep you guys updated, I'll be needing a lot of advice and help.