running rich at wot why?

[blackstallion]

my car has been running very rich at wot i had turn off the alky from keeping it from sputtering,i have the stock 237 regulator
02's are in the 850-930mv at wot boost is set to 13 pounds when i floor it i hear it knock but it goes away very quickly i get maybe 1 degree on a shift only hear knock when boost comes in problem is worst when its colder my main concern is the wot rich,i use a 2500 snap on scanner at wot intergrator and bl look normal.Its does have a cracked driveside header,also when i raise the boost it starts to surge sometimes backfire so i can't raise the boost to lean it out cuz it just backfires and surges car runs fine at cruise and at idle.

 

[scottyb]

Chip match your injectors?
New O2 sensor?
MAF reading at WOT?
Fix that crack!

BTW, the 237 is not the stock FPR. It's a few pounds higher than the stock 233.

 

[turbojoe]

Concerning the cracked header, Can you actually see the crack? The reason i ask this is because i'm chasing a rich problem of my own, but i can't see the DS header crack, I can hear it though.

 

[blackstallion]

30 pound injectors,maf reads 235,o2 sensor about 7 months old ac delco purple wire,no codes good 02 crosscounts,i can see the crack,do some cars spool quick with the cracked header

 

[XLR8]

I thought the snap on scanner reads O2 mv 100 higher than Scanmaster/T-link/DS.
13# of boost with alky sounds really low. Are you MAF and coil pack in good shape? Can you swap out with known good uits?

 

[turbojoe]

From what i've been reading, cars with cracked Ds header spool terribly. Mine spools very slow and i can hear the air being sucked into crack. Almost sounds like valvetrain noise (tick tick tick). I am also very rich, probably from cracked header. I can't see mine though. I think i will pull it off to get a better look.

 

[Turbo6Smackdown]

From what i've been reading, cars with cracked Ds header spool terribly. Mine spools very slow and i can hear the air being sucked into crack. Almost sounds like valvetrain noise (tick tick tick). I am also very rich, probably from cracked header. I can't see mine though. I think i will pull it off to get a better look.

I know this is old but it promted a question to be asked-hitting the gas on a car with a cracked header SUCKS air into the crack? I thought air was coming OUT of the crack, that's why the spooling was reduced a little. If air's being sucked into the crack, that's ADDITIONAL air; so then at that point wouldn't the turbo spool faster lol? Or, if more airs being sucked in, wouldn't you be lean not rich? I ask because I'm trying to diagnose a similar problem.

 

[Mike Licht]

What chip do you have and what boost was it programmed for? if you have an alky chip you are going to have to turn up the boost. I have seen lots of people lately getting into real problems because they are trying to be "safe" and their tunes are so far off they cause problems