Perfect air/fuel ratio?
#2
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Also what is considered to be in the "GOOD" range for a greddy miata?
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the vortec is not supposed to have any effect at idle. In fact, it shouldn't do anything until manifold pressure is positive over atmospheric.
the problem is probably elsewhere (or the WB is improperly calibrated). what's the rest of the system?
<edit> snow, huh? fuel mix is primarily determined by engine load, but ambient air temp and coolant temp also factor in. still you should idle in closed loop, somewhere around 15:1...
the problem is probably elsewhere (or the WB is improperly calibrated). what's the rest of the system?
<edit> snow, huh? fuel mix is primarily determined by engine load, but ambient air temp and coolant temp also factor in. still you should idle in closed loop, somewhere around 15:1...
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Last edited by Ben; 03-16-2007 at 03:55 PM.
#8
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Alrighty so i just put the wideband in and i cant drive it around because there is 6" of snow on the ground here but i warmed it up and it is at about 11.5 on idle.
I have a vortech afpr and i have the 7:1 disk in there now so Im gana try a smaller ring to get the a/f up in the 12's.![CRX](https://www.miataturbo.net/images/smilies/pissed.gif)
I have a vortech afpr and i have the 7:1 disk in there now so Im gana try a smaller ring to get the a/f up in the 12's.
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what injectors are you running? the vortech wont do anything to AFRs at idle, unless it's stuck closed.
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Nay.
The vortech should not be doing anything at idle, regardless of disc. Check (and then double-check) the vacuum line running to it. Make sure the fuel hoses aren't reversed. All that jive. But don't go changing discs yet.
Are you running a non-stock fuel pump?
The vortech should not be doing anything at idle, regardless of disc. Check (and then double-check) the vacuum line running to it. Make sure the fuel hoses aren't reversed. All that jive. But don't go changing discs yet.
Are you running a non-stock fuel pump?
#10
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Heres my set-up.
https://www.miataturbo.net/forums/vb...do=view&id=642
1.8 tan injectors and a walbro 190HP pump.
https://www.miataturbo.net/forums/vb...do=view&id=642
1.8 tan injectors and a walbro 190HP pump.
#12
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if worst comes to worse and you cannot solve it, drill into the small circle on the AFM. turn the screw that's underneath it counter-clockwise untill your idle reaches 14.7.
the car must be fully warmed up first with correct timing and idle speed.
the car must be fully warmed up first with correct timing and idle speed.
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Maybe he'll end up getting a near-stoich idle afr, but if there is an issue with vortec or o2 system, the car won't cruise well, even if your method fixes the idle mix.
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you need to do what I wrote a couple posts ago.
Your car should regulate itself around 14.7:1 when you are cruising. 12:1 is only appropriate for accelerating in positive mani pressures.
Do you have an O2 sensor installed?
Your car should regulate itself around 14.7:1 when you are cruising. 12:1 is only appropriate for accelerating in positive mani pressures.
Do you have an O2 sensor installed?
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Well the evidence points to no O2 sensor feedback. I'd check it to see if its voltage output dithers from around .3-.7 Volts.
To test: Remove plug 2 from the ecu, with your fingernail flip open the little tabs on the side of the connector. Then the top of the connector will swing up, allowing access to the pins from the wire side. Use an open paperclip and push it in over the o2 wire's pin (2N I think, not sure, it's the center wire and has a gray shield around it). The o2 wire will release from the rest of the harness. Plug the harness back in, start the car, and test the o2 wire that you pulled out of the harness for voltage with your DMM.
Don't ask me how I know how to do this.
To test: Remove plug 2 from the ecu, with your fingernail flip open the little tabs on the side of the connector. Then the top of the connector will swing up, allowing access to the pins from the wire side. Use an open paperclip and push it in over the o2 wire's pin (2N I think, not sure, it's the center wire and has a gray shield around it). The o2 wire will release from the rest of the harness. Plug the harness back in, start the car, and test the o2 wire that you pulled out of the harness for voltage with your DMM.
Don't ask me how I know how to do this.
#18
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Seriously though. If you follow the black wire coming off your O2 sensor you'll find that it terminates at a small black connector somewhere in the behind-the-head region. Don't worry, it's accessable. Unplug the connector and probe it here. Much easier.
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Or, since this is a '91 with a single-wire sensor, just unplug the O2 sensor itself and measure there.