Hey guys I am having trouble with my turbo swap running way to rich. I have wideband o2 sensor and it reads 10.7 at idle although it will idle at 12.0 sometimes if I play with the throttle but goes back down to 10.8. It seems to run decent when it in load around 14.5-15.5. I took the car to a shop and they put it on their sniffer (thats what they called it) and confirmed the wideband readings of being too rich.

Facts and things about the car:
-S4 Turbo swap no porting whatsoever
-Upgraded oil pressure regulator
-FMIC
-Double throttle delete
-All emissions removed along with BAC (and thermowax for the double throttle)
-3inch downmipe and exhaust
-BNR Stage 3 Turbo
-Stock 550cc injectors
-Stock Turbo ECU, MAF, Pressure Sensor
-Fuel Cut Defender
-External Fuel Presssure Regulator along with the parallel fuel rail system set to 38psi.
-Walboro 255 fuel pump
-Regrounded Injector grounds near the ECU

Things I have checked:
Adjusted the TPS the resistance way not the voltage way. New O2 sensor. Checked for voltage at the ECU connector for O2 reading and it was reading 4.2-4.4 when warmed up. Checked the MAF resistances looked good. New Air Intake Temp sensor.
I disconnected the fuel cut defender and plugged in the MAP the regular way to see if anything changed nothing changed. New Coolant Temp Senor.

I checked for flash codes through the green connector near the driver side strut tower. No codes present, but to see if it was still functioning properly I disconnected the Air Intake Temp sensor and it threw a flash code.

I have attached a video to let you guys see what I am seeeing through the wideband gauge. I play with the throttle a little.

Any Input would very much help me. Thanks

 

To clarify, you're running a bone stock ECU, so not even an RTEK? There lies the problem...

 

Ya, you have a 255 walbro and stock ecu, and emissions delete, the emissions delete wil make it pig rich on its own

 

I have a Rteck 1.8 but I don't have the correct injector size. I wasn't sure what would happen if I plugged it in with stock injectors.

 

I believe I still have the stock air pump and PCV valve and I will reinstall that, that is if the N/A emissions equipment will bolt up to turbo engine?

 

Thats kinda putting a band-aid on the problem honestly

 

That Rtek 1.8 requires 720's does it not??

 

It might, but in that case it would be running lean, correct?

 

Is that under boost? If so, that is too lean. Stock ecu produces AFR's in the mid 11's to 12 at stock boost levels.

The O2 sensor voltage is supposed to be 0-1 volt. Many widebands have a 0-1v output for this function. You can't connect the wideband's 5v signal and expect it to work.


Is that the sensor on water pump housing? How about the sensor at the bottom of the radiator?

Also, an air pump adds about 1.0 AFR point at idle. My rtek with the stock tune and air pump runs about 12ish AFR at idle. Without the air pump, that puts you about 11, so you aren't too far off.

And Fuhnortoner is correct. Do not use stock injectors with an rtek 1.8. It will run lean.

 

Under full boost its 12.0 to 13.0 cruising down the highway not in boost its 14.5

My bad on the O2 reading I moved the decimal one over. I was reading .42 at idle I was taking a voltage reading off the stock O2 sensor.

The sensor was off the water pump housing was replaced. The one on the bottom of the radiator is plugged in but has not been replaced or even tested, nor do I know how to test it.

I will be looking for a turbo ACV if you have any leads send them my way.

I will not run the Rtek with stock injectors thank you.

 

Correct, but I am currently using the stock ecu

 

Does this cause a rich issue? I'm running pig rich at idle as well, apexi power fc, and never thought that sensor played into this...

 

Depends if the PFC, looks for that input. Sorry, I'm not familiar with pfc's.

It's one of the inputs used by the stock ecu to tweak the mixture. General stock ecu programming is "cold=rich" but not much detail is provided beyond that.

 

First off: BNR Stage 3 + stock injectors + stock ecu is a recipe for a blown engine. I wouldn't run any boost until you have your injectors and ecu upgraded.

12-13 AFR is a little higher than I'd expect to see. I think the BNR is contributing a lot here.

The O2 sensor readings looks odd. 0.4v is 'lean' and doesn't match the 10.x AFR you're seeing at the wideband. Maybe the sensor is not good?