fairly new to the turbo game (STS single turbo)...I am running a more aggressive tune at 11.5:1 at full boost but....In the cool morning at cruzing speed (80 in 6th gear) the AF is 15's:1 but as the day warms up in jumps to 17's:1. Is this normal???? I may have to de-tune or run another map on the Utec for racing and daily driving. Any help would be apprecitated.

 

See if you can recalibrate your Wibeband first and make sure it is working properly. If you are leaning while cruising then it could be your Wibeband reading it wrong or your 0 column wasn't tuned right. I know Goosegoos had some problem with his A/F when cruising and on low boost and it turned out that his Throttle Body was dirty. Clean your MAF, and check the TB and see if it makes a difference. How's your A/F when on boost?

 

AF under boost is no problem. Leans out at 3000 rpm at cruising. I suspect that the ECU is running by itself without utec involvement without any boost present. I also thought about changing out the O2 sensors....they are original with 72k on the car and 2 different forms of FI SC & TC. any other thoughts??? thanks for the reply

 

^ are you able to connect up to your UTEC to view the fuel map? Most likely the tuner scaled your injectors for the entire 0% column (up to red line), which would mean the ECU isn't taking over while cruising - the UTEC is piggybacking by doing MAF pull-down and adjusting MAF voltage to compensate for larger injectors. If you try all of the other stuff and it doesn't work, you may need to just add more fuel in the 0% column above 3,000 RPMs.

 

Great information...thank you very much.

 

If you can connect up to the UTEC and capture the fuel map, post it here and we can help you out.

The fact that your cruising AFR leans out as it gets warmer is interesting though. I would first do what athenG said to make sure everything is clean and calibrated. What wideband sensor are you using btw?

 

AEM wideband. I'm a computer idiot so I posting my maps is scetchy I'm at work right now so I'll have to run all this stuff down this afternoon. If I can pull my head out....I'll try to post my fuel maps

 

Any chance my ECU is just going through a "learning curve"? I pluged in a diff map and went full throttle racing in pre-season autoX.....I didn't notice the lean problem until after a full day of AutoX (Brag time...I posted fasted time of the day) I also was way low on fuel my last run (fumes) and had to dump 3 gal in just to get home. Thanks for all the info...I'm just tossin out other ideas. Jim

 

I had a problem way back and for some reason my A/F start leaning after driving the car for 2-3 hours straight (NYC Cruise ). I made changes on my Map and also the Temp Compensation and that didn't fix it. Went home and park the car and disconnected the battery for 5 hrs and everything went back to normal. I say reset your ECU and see if that makes a difference too.

 

Thanks..I'll give that a try too.

 

How recently did you purchase your AEM Wideband? I was told about two weeks ago when I ordered mine that there was a bad batch of them from AEM and I had to wait for them to get some new ones in. Just a thought.

 

the stock ecu can scale quite a bit. I ran 650cc injectors with no EMS for over 200 miles. Only idle is a lil whacky.

You car is trying to run mid 14 AF when not on boost. Dont worry about it. The stock ecu has enough range to scale over most any values in the 0 column.

if if your wideband wasnt calibrated right, the UTEC has very minimal control at 0% load.

 

I'm starting to think a wideband recal is in order... thanks- Jim

 

i wish my car cruised at 15-17:1 af. gas mileage would go way up. we tried to get it do that at Forged Performance, but the stock ecu wouldnt let you scale 0% load enough to do so.

 

Ok...the end result...so far. I let the ECU reset and....no problems at all. AF ratios are perferct across the board with and without boost. Thanks for the input out there, I'll post up if something weird happens. Jim

 

Great!! I freaked out when that happen to me and in my case I was leaning also on low boost Reset the ECU fixed it