My setup is basically stock....

Just a lid, a 75 dry shot, and a tune from Bryan Herter at PCMfor Less...

Ran it for the first time and car hit 16.8 AFR before we shut it down. Gave a quick run NA to see how it would do and still went lean like that.

Checked fuel pressure at idle was about 60psi and ran it on the dyno and stayed right there also.

No visible vaccuum leaks and MAF looks clean. I am going to search for more vaccuum leaks and possibly swap the MAF to see if there is any improvement (Only 33.8 lbs/min at the 353hp mark)

Any other ideas?


Thanks for any help

 

Tell the shop to check their wideband. They do go bad and when they do, it will show every car to be lean.

I had this problem at my shop and it drove me crazy for a couple of days untill we decided to replace the wideband.

problem solved.

 

Jeff,

That is what I thought as well because I showed no knock and made good power....which neither seem likely at 17.0:1, but when I logged the car it showed about 100 grams/min low on the MAF....Not sure about that

 

was it showing lean ONLY at WOT? if so, I really think it could be the wideband. Im not even sure if a car will run at 17.0

 

Once again, this is what I thought.

 

What kind of car and exhaust? Had a 08 Vette with the stock bypass tips on it. We put the Dynos WB O2 in the muffled side of the tip and when the bypass tips opened, it sucked air back in though the muffled side and showed max lean on his wide band. I had mine installed in the header, so we just tunned off of it.

 

Try cleaning the MAF or your tune is just bad.

 

Try cleaning your MAF or also I've seen 2 or 3 MAFs that flat out didn't read at wide open throttle. One belonged to a friends girlfriend. That car was high 16's but the fuel trims around town looked nice. At wide open the MAF barely saw 200gm/sec so after a cleaning didn't fix it we put a new one on and it followed the same AFR all stock cars do.

 

Thanks....I cleaned it and checked for vaccuum leaks(none) tonite.

The wires were dirty on the qtip so gonna try the dyno one more time and if that doesnt work will swap the MAF.

 

Plug readings?

 

No plug readings yet.

 

turned out to be the shops wideband after all.