AFR at Idle?
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AFR at Idle?
Anyone know roughtly what our cars should run as far as the Air Fuel Ratio at idle with the stock ECU? I read somewhere that a good idle should by in the 12.2-12.8 range. But I don’t see why you would want it that rich? Does the ECU hunt for Stoich??? At idle? I was getting 14.7-14.9 readings at idle last night. Just want to make sure I don’t have a problem with something.
Thanks,
Robert
Thanks,
Robert
#2
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Approx 13.0 give or take .2
I can get my afr to 14whatever, but the idle will start being bumpy. Not a desired effect for me. I've seen at least two other posters that said theirs was in the 13 range.
Oh....a little caveat here. That is WITHOUT A AIRPUMP AND ACV installed. If the airpump and acv are inline, then I do indeed get on the order of 14.7 whatever.
Oh, the ECU ain't a huntin at idle. It be a huntin when cruisin
IF your getting 14 whatever at idle and you have your airpump/acv intact......then pull the vac line that controls the swithing diaphram off the acv and plug it momentarily and take another look at the afr. It will now have gone from 14whatever to the 13afr range. That's a result of the air from the airpump now being dumped someplace other than the exaust ports.
I can get my afr to 14whatever, but the idle will start being bumpy. Not a desired effect for me. I've seen at least two other posters that said theirs was in the 13 range.
Oh....a little caveat here. That is WITHOUT A AIRPUMP AND ACV installed. If the airpump and acv are inline, then I do indeed get on the order of 14.7 whatever.
Oh, the ECU ain't a huntin at idle. It be a huntin when cruisin
IF your getting 14 whatever at idle and you have your airpump/acv intact......then pull the vac line that controls the swithing diaphram off the acv and plug it momentarily and take another look at the afr. It will now have gone from 14whatever to the 13afr range. That's a result of the air from the airpump now being dumped someplace other than the exaust ports.
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That should work. But pulling that vac line that sticks straight up on top of the acv will do the same thing. Be sure to plug the vac line if you do that. Or if your belts start slipping at high rpm without the belt.......remove the airpump hose b/t the airpump and the acv. Just a little bit of airpump noise will be the result. You don't need to plug anything if you pull that hose off. Leave both ends open will be ok.
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I still have my ACV on the car, and my smog pump hooked up, but I have the pipe that goes to the cat (no cat) plugged off. Is the pump still injecting air into anything?
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Yes indeedy the airpump be a pumpin air into the exaust ports and the last time I looked the exaust ports are prior to the O2 sensor whether its wideband or not. That's where most of your airpumps air goes on a RX-7.
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You were right Hailers thanks. I pulled the belt (well, cut it ) off the smog pump, and the AFR dropped a good 2.5. I am analizing my first logs of real runs now. only 8 PSI, but running ALOT leaner than i thought at low RPM's 2200-3300 ish, I am hitting FULL stage 1 boost by 2200 RPMS! But from 3500-7000 I am right where I want to be for my low stage of boost. Next is to tune the high stage (I think I will set it at 13 PSI) woot!! I have never run over 8 PSI on this car yet, I wanted to wait for the WB.
what is incredable to me is the boost hold, and boost responce, I am hitting boost within 0.8 seconds of hitting the gas. And it hold boost within 0.3 PSI all the way across the board, I am delighted!!
-Robert
what is incredable to me is the boost hold, and boost responce, I am hitting boost within 0.8 seconds of hitting the gas. And it hold boost within 0.3 PSI all the way across the board, I am delighted!!
-Robert
Last edited by Rpeck; 01-14-04 at 11:03 PM.
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basically the why of these workings, is that the cats need to see/work best at 14.7:1. the engine wants to idle best at 12.5-13.2, this is too rich for the cats by themselves to clean up. if you have the engine running leaner than that it will misfire and that is both bad for the cat, and emissions. so they inject the airpump air into the exhaust ports to make the cats see 14.7:1.
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Originally posted by Sideways7
I always thought that 13PSI was out of the effeciency range for the stock torbo. If I'm wrong, please correct me.
I always thought that 13PSI was out of the effeciency range for the stock torbo. If I'm wrong, please correct me.
well, done witht he motor, I am still thinking about handleing mods next.
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"Eibach springs and KYB AGX shocks"
That seems to be the route I am leaning towards, not overly pricey.. and proven time and again, lots of people have and love that setup.
As for the rest of the handling stuff I am fairly ignorant to it still. I am one of those 'research and decide' people, and I just havent looked into that stuff yet.
I plan to run Auto-X locally this summer, I went out to a few events and watched, talked to alot of people looks like a hell of alot of fun, so i figure before then I better do some modding.
here is link to some pictures I took at the Auto-X here in Stockton Stockton Auto-X meet
That seems to be the route I am leaning towards, not overly pricey.. and proven time and again, lots of people have and love that setup.
As for the rest of the handling stuff I am fairly ignorant to it still. I am one of those 'research and decide' people, and I just havent looked into that stuff yet.
I plan to run Auto-X locally this summer, I went out to a few events and watched, talked to alot of people looks like a hell of alot of fun, so i figure before then I better do some modding.
here is link to some pictures I took at the Auto-X here in Stockton Stockton Auto-X meet
Last edited by Rpeck; 01-15-04 at 12:50 AM.
#17
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Originally posted by Sideways7
Check out the handling mods I've got, they're incredible. Its got incredible road feel and response, and would be even better with new rims/tires. If you take it to the track, the camber adjusters can be pretty useful.
Check out the handling mods I've got, they're incredible. Its got incredible road feel and response, and would be even better with new rims/tires. If you take it to the track, the camber adjusters can be pretty useful.
I don't see any anti-sway bars...
I don't see a full Energy Suspension bushing kit...
I don't see no strut tower bars...
What I went through...
Tokico Illuminas
Ground Control coilovers
Ground Control rear camber adjust bar
Cusco front camber plates
Cusco front upper strut tower bar
Cusco front lower bar
Cusco rear upper bar
Suspension Techniques anti-sway bars
Racing Beat adjustable endlinks
Energy Suspension full bushing kit
Racing Beat DTSS toe eliminator bushings
-Ted
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Originally posted by RETed
The 13B can take a lot of fuel at idle before it starts becoming unstable. I've seen AFR's down to 10.x:1 at idle!
-Ted
The 13B can take a lot of fuel at idle before it starts becoming unstable. I've seen AFR's down to 10.x:1 at idle!
-Ted
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Originally posted by RETed
Oh pulease...
I don't see any anti-sway bars...
I don't see a full Energy Suspension bushing kit...
I don't see no strut tower bars...
What I went through...
Tokico Illuminas
Ground Control coilovers
Ground Control rear camber adjust bar
Cusco front camber plates
Cusco front upper strut tower bar
Cusco front lower bar
Cusco rear upper bar
Suspension Techniques anti-sway bars
Racing Beat adjustable endlinks
Energy Suspension full bushing kit
Racing Beat DTSS toe eliminator bushings
-Ted
Oh pulease...
I don't see any anti-sway bars...
I don't see a full Energy Suspension bushing kit...
I don't see no strut tower bars...
What I went through...
Tokico Illuminas
Ground Control coilovers
Ground Control rear camber adjust bar
Cusco front camber plates
Cusco front upper strut tower bar
Cusco front lower bar
Cusco rear upper bar
Suspension Techniques anti-sway bars
Racing Beat adjustable endlinks
Energy Suspension full bushing kit
Racing Beat DTSS toe eliminator bushings
-Ted
#20
Lives on the Forum
Originally posted by Rpeck
what are we talking for all that? $2-3k? or am I way off? Just like to know ballpark price of what I am looking at.
what are we talking for all that? $2-3k? or am I way off? Just like to know ballpark price of what I am looking at.
Ground Control coilovers, $399
Ground Control rear camber adjust bar, $250
Cusco front camber plates, $250
Cusco front upper strut tower bar, $150
Cusco front lower bar, [$100
Cusco rear upper bar, $150
Suspension Techniques anti-sway bars, $300
Racing Beat adjustable endlinks, $63 each set
Energy Suspension full bushing kit, $150
Racing Beat DTSS toe eliminator bushings, $40
Prices come out to a little over $2,500, but most of these prices are full retail. Street prices would be more like $2,000.
-Ted
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