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.

 

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.

 

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.

 

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.

 

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.

 

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.

 

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.