Yep, I've got great spark, 120psi on both rotors, freshly cleaned injectors (cruzinproformance) and a couple mods . . .

But according to the WBO2 (that was freshly calibrated before installation) I am running ~25:1 fuel! Mega lean? Beyond free air? I Hit the gas and it drops to ~15:1 for a moment for the acceleration enrichment. Let off the gas and ratios of 34:1 occur! How is that possable?

So we looked up the operation of the O2 sensor and it says readings like this can be caused by blocking the sensor by huge clouds of unburned gas, if you're running ultra rich or missing.

Any ideas why it is so rich? Fuel pressure regulator? Or for some reason is this normal? Could the WBO2 sensor be wrong? (It reacts fine, and was freshly calibrated before install)

Thanks!

 

Did you get it up to operating temp. first?

 

The WBO2 has its own heater, Its bad for it to run without the heater. It takes about 5 seconds or so to warm up. The car was also at operating tempeture.

I should also add that my car takes a whole lot of cranking to make it start.
It used to start with just the flick of the wrist, but now it doesnt anymore (I have no clue why, it changed a while ago). My GXL also starts almost instantly.

 

I'm probably reading this thread wrong, but........I don't believe a car/engine will run at lean ratios of 25 whatever to one. The wideband is wrong if the engine is actually running and you see figures like that.

If your only seeing figures of 25/1 or even 45/1 when you let off the throttle, that's normal. But if you read 15/1 when stepping on the throttle, thats too lean for some reason. SAFC.

I'm probably reading the thread wrong. Missed something here.

 

I'm saying the WBO2 reads ultra lean when it is really means ultra rich.

I see those figures at idle.

I am not going to SAFC. I'm going megasquirt (thats why I got the WBO2 in the first place)

 

What does it read when cruising down the hwy at a steady sixty? And someone is bound to ask what size injectors and what fuel pump.

 

Stock injectors and stock fuel pump, this is an S5 NA

I'm going to do a run to sixty and cruise later this week.

 

oop sorry, just trying to help.

 

It's cool, I'm just trying to cover everything

 

can you try the wideband on a different car that has a wideband on it, so you can confirm the wideband works properly

is it possible there is air getting injected dilluting the exhaust before the o2 sensor, it will make your readings ridiculously lean.

 

Nah, no air before, the O2 sensor is before the cat, thus before the airpipe.

Before that, is a new RB header with a new gasket on it

Good idea though.

 

10:0 to one is rich and 20.0:1 is stupid lean...... at crusing speeds, rotary's will start to buck if the A/F goes above 14.5:1 or so. Under a load, they will detonate at this range.. (turbos will detonate under boost if the A/F's get to 13.... less under higher boost... in general... intake charge temp plays in as well.)

Take the wideband out..... give it power, let it warm up and hit it with a propane torch.... it should read right around 14.7:1 (propane burnes at stoich in the air.....

At idle... you should be seeing right around 13.0:1... RX's will not idle much leaner than 13.3:1 or so they will HUNT HUNT HUNT.. much richer than 12.6:1 and the idle will dance around. So if your car is idleing normally, and your WBO2 is showing something out of this range.... its bunked

On an N/A with exhaust and intake mods, the A/F's tend to get really rich at higher RPM's under WOT.. Before i put the SAFC on my old GTU i was seeing A/F's in the 10's and loosing a LOT of power after 5K....

What type of WBO2 is it and how did you calibrate it and where is it mounted.... something is not right with the WBO2

Also.. Are you planning on ditching the ECU injection control and running the Megasquirt to control your injectors????? .

most guys i know use the megasquirt as an additional injector controler for a turbo car..... N/a's usually need fuel taken out

The Megasquirts are a cheap and reliable way to add Fuel injection to a car that never had it... but i wouldn't replace the stock ECU with it..... the stock ECU and an SAFC is going to be a MUCH better combo.

 

Though I am not absolutely 100% on this since I did not study the stock emissions b.s. that much, I do suspect strongly that the stock configuraion injects air @ the exhaust port sleeves under some conditions, and if the acv&cv is not functioning properly maybe under all conditions. Check this one out before going crazy.

Did you install the ACV blockoff plate that comes with the RB header?

 

this is going to be a dumb question, but have you tested this on the road? under load? i think that you should at least try wailing on the car a bit to see if maybe its just breaking in.
ive got the same starting problems after changing injectors.. perhaps it has something to do with the stock injector wiring being disturbed. those things are very sensitive id imagine.

 

Did you calibrate it?

On my friends you have to let it calibrate before running.

Maybe you got a faulty sensor?

 

What brand of wideband, and what brand of sensor... for curiosity's sake.

 

I think the WB is out of whack. If the car will run, it will be within ratios the sensor would have no problem interpreting.

 

ALL true!
My car bucks/hesitates if goes to 14.7-15.1

very good pointers

 

Check your input from the water thermo sensor at the ECU at idle, cold and hot, and compare with FSM specs. A faulty sensor connection caused this on my car years ago...

 

No, I'm still running emissions with a cat. This is an S5

It wont be running an ACV for much longer though!

 

I plan to do that this Thursday. The stock injector wiring was completely cut out and replaced with a single, short wire to the ECU.

The sensor was calibrated before instalation, twice, just to make sure. It was supposed to read open air, then you are supposed to put a butane lighter under it to see it react. It passed all its tests with flying colors.

Techedge WBO2 with the VW O2 sensor, I forgot the serial on the sensor, but I'll get it for you tommorow.

 

My idle is hunting.

Thats a great post, full of information that will help me. Thank you very much
Why dont you like the Megasquirt? My stock fuel system is totally out of whack for my needs (fuel and ignition control, removal of TPS and AFM, removal of practically all stock wiring and emissions controls, removal of MOP, ACV .. . etc etc) And the MegaSquirt cost $140 while an SAFC costs more and does much less

AWESOME!! Thank you for the suggestion, I will definitely be checking that tommorow!

 

I believe you should maybe read the fsm and how the acv works and where the air in injected. It's not as you describe. Air is injected into the EXAUST PORTS. The exaust ports are ......prior to the o2 sensor. The split air pipe does bypass this, but the amount of air delivered by the split air pipe is anemic compared to the exaust port air.

Not that this has anything to do with the problem in this thread. The wideband is corrupt, not the car/engine.

 

Interesting.

I didnt know that they did that.


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Edit: I will have to read up more thoroughly on the ACV.

 

Even with the acv functioning and putting air in the exaust ports, the afr will still be approx 14.7 give or take. Let's say I was idling with the airpump/acv intact and working. The afr will SHOW in the 14.7 range. Now if I leave the engine idling and disable the acv by pulling the Relief Solenoid plug off (disables the acv), then the afr WILL drop to the real idle mixture which will be in the 13.0 range, give or take a point.

So I'm almost positive the acv is not causing your untrue readings.

I've got to copy down what YEARSOFDECAY wrote and the next time someone of this forum talks about adding fuel to a non turbo, refer them to what he wrote. I saw exactly what he saw on my 86 non turbo at the time I had a wideband on it.

Sorry about your problems with the wideband. I can't diagnose what is wrong with it. I'm sure your using the TechEdge site at http://autos.groups.yahoo.com/group/...b/message/3066

Keep on trying to get it to work. It's a useful device.