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Old 03-07-2014, 04:20 PM   #1
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Default JRSC / AFPR 1.6 lean at idle / cruise

So I finally got around to hooking up an innovate lc-1 wideband today. Took the car for a drive, and at idle the afr reads like 16:1 17-1. Under boost I am seeing anywhere from 11:1 to 13:1 depending on how hard I get on it. The further I push the pedal, the lower they go. When I back off the throttle to cruise (no throttle), the afr gauge shoots up to 22:1. What gives? I have tried adjusting the afpr, and it didnt help. It also seems that if I am not driving it hard, and just putting around, afrs will be in the 14-15 range.

When I got back to the garage, I pulled the plugs, and they are black with the exception of the ground strap, which is white. ???

My setup is a 1.6, jrsc, bipes set at 9* base, pulling 6 @ 1500 rpm to be on safe side until I get this worked out, afpr, header, full exuast, no cat.

PS I had the bung welded for the wideband in an old cat that had the honeycomb broken out. Would such a large volume of air (compared to a 2.25" pipe) cause a faulty or lean reading?

Last edited by lexintexan; 03-07-2014 at 05:36 PM.
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Old 08-13-2014, 11:28 PM   #2
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No what are you running for a fuel system?
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Old 08-14-2014, 12:22 AM   #3
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Quote:
Originally Posted by lexintexan View Post
So I finally got around to hooking up an innovate lc-1 wideband today. Took the car for a drive, and at idle the afr reads like 16:1 17-1. Under boost I am seeing anywhere from 11:1 to 13:1 depending on how hard I get on it. The further I push the pedal, the lower they go. When I back off the throttle to cruise (no throttle), the afr gauge shoots up to 22:1. What gives? I have tried adjusting the afpr, and it didnt help. It also seems that if I am not driving it hard, and just putting around, afrs will be in the 14-15 range.

When I got back to the garage, I pulled the plugs, and they are black with the exception of the ground strap, which is white. ???

My setup is a 1.6, jrsc, bipes set at 9* base, pulling 6 @ 1500 rpm to be on safe side until I get this worked out, afpr, header, full exuast, no cat.

PS I had the bung welded for the wideband in an old cat that had the honeycomb broken out. Would such a large volume of air (compared to a 2.25" pipe) cause a faulty or lean reading?
Not sure why you are lean at idle, but all your other A/F numbers are reasonable.

Keith
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Old 08-14-2014, 11:05 AM   #4
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I am running a JRSC afpr for fuel, and a bipes for timing. Getting around 4-5 lbs of boost. Since that post I have put the factory cat back in, no change. My idle afr doesn't change regardless of how much I turn up the afpr, but it does get harder and harder to start if I add too much fuel (base pressure).

This has kind of just become one of those issues I am just living with and not worrying about. I hope I am not doing any significant damge by having a 16:1 idle afr.

Last edited by lexintexan; 08-15-2014 at 01:06 PM.
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Old 08-21-2014, 10:54 PM   #5
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Idling at 16:1 wont do any long term damage. As long as its not affecting your cold start, then you are fine.Idling that high might make it feel like it stutters off the line, or bogs.

Its also ok for the car to lean out to when you get off the gas pedal, as long as it transitions back quickly if you give it throttle again.
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Old 01-18-2015, 10:09 PM   #6
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Does the JRSC powercard work for you? I have an older version that cannot be tweaked. I got it with the m45 kit for my 97 miata. The thing is, the vacuum hose leading to the intake was clipped off close to the card. Is this repairable? Do I just replace the hose or buy a later version?
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Old 01-18-2015, 10:14 PM   #7
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I would certainly replace the hose, and see what happens. Any reason you are not wanting to replace the vacuum hose / use the powercard?
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Old 01-20-2015, 11:16 PM   #8
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Not sure if a solution to the original post has been devised, but here are some thoughts:
-afr during decel is probably fuel cut, this is fine.
-the FPR is a 10:1, which could mask other issues when not in boost
-injector dead times are strongly related to system voltage. Idle voltages should be around 13.5V or better. If they are low, the injectors will not deliver as much open loop fuel as the ECU is intended to deliver.
-having the WB in the cat will make it prone to cooling during idle, which will cause bad readings. These sensors must maintain a pretty high temperature to function. Retarding the base timing can result in higher EGTs, but will cost power. Abase timing as low as 6 degrees can be used, but a better solution is to move the sensor closer to the mani. Reduced base timing will adversely impact NOx.
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Old 01-22-2015, 12:52 PM   #9
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I did wind up getting the issue resolved thanks! In the end I think it was an old / sticky afpr. I cleaned it and re assembled again and after some more adjustmet all seemed to be well. I no longer have the car that had that set-up but that is interesting to know about the wideband sensors needing a good bit of heat. Would that still apply to say, an innovate brand one that heats itself up before reading? I never touched it while powered up so I dont know how hot it would get on its own power??
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Old 01-22-2015, 06:28 PM   #10
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I believe that the Innovate runs closed loop control on the sensor temperature. If memory serves, you need several hundred degrees F to keep the sensors in range.
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