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AFR's: ACV/Relief Solenoid/Port Air/ETC clarification

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Old 10-30-08, 08:32 PM
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Rotary Dynamics

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AFR's: ACV/Relief Solenoid/Port Air/ETC clarification

I just wanted to get some clarification on what and when things affect afr's

S4 NA

Idle:

Poppet is open and air is injected into the exhaust ports = raising afr's to lean condition according to wideband

Solution: Remove blue plug off relief solenoid, this dumps air into the silencer in the engine bay providing an accurate AFR reading from wideband

Cruise:

While cruising the ECU/O2 sensor tries to keep a 14.7 AFR.

Solution: To tune at cruise, unplug the O2 sensor


WOT:

No air is duped into exhaust affecting AFR's, stock O2 sensor doesn't affect AFR's.

No solution required since AFR's are read accurately at WOT.
Old 10-30-08, 08:39 PM
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Sounds right to me. The converter will be damaged if you leave it like that all the time. How long? Got me. I'd say a month or two on the outside.
Old 10-30-08, 09:07 PM
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Rotary Dynamics

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A bunch of that info I got from various threads with your replies, just wanted to consolidate and confirm.

I don't have a cat so I can probably just remove the plug for an extended period of time with no issues.

Thanks.
Old 10-31-08, 06:07 PM
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Rotary Dynamics

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Hmmm, interesting finding: at idle wideband read above 16.00, pulled the blue plug off and it turns out it idles in the high 11's(on a hot engine), seems way to rich for idle.
Old 10-31-08, 06:35 PM
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that's a little richer than normal... you can adjust your variable resistor a little bit. most cars idle in the high 12's without the airpump, sometimes a little leaner. rotaries need a rich idle for stability.
Old 11-04-08, 10:16 AM
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Since the O2 sensor doesn't do anything at idle or when you gun it, might as well leave it plumbed in to get good gas mileage on cruise.

I run an eManage, and adjusted the maps for my increased fuel pressure - cutting enough fuel to get it back into the range of the o2 sensor - result: started getting the 14.7 AFR's again as opposed to the 11-12 I was getting.

My idle on cold is very rich, but it rises to mid 12's when it's warm.

I junked all the emissions stuff except the crankcase venting, and run no cat.
Old 11-04-08, 11:30 AM
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Originally Posted by theory
Hmmm, interesting finding: at idle wideband read above 16.00, pulled the blue plug off and it turns out it idles in the high 11's(on a hot engine), seems way to rich for idle.
two things.

1. the idle is tuned rich to eliminate misfires, misifires = high emissions, so they cant do it.

2. in the book "rotary engine" they have a little graph of fuel consumption at idle with and without the air pump. with the air pump the engine can be run leaner at idle.
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