AFRs staying at 10.2??

[BoostBuddyGSX]

So.... at WOT between 3 and 7k, my AFRs are pinned at 10.2. Weird??Or normal..? I set my boost level at 19psi and at WOT I was hitting fuel cut!! so i turned it down 1psi and i set my corr. value on my S-AFC to +20% from 4 to 7k and its not happening anymore...for now... Also, I'm bogging at throttle release. I'm thinking maybe the MAF? any ideas on whats going on guys??

 

[zhjiln]

700cc injectors on a SAFC ?? isn't the maximum 650cc or something for safc..


nothing wrong with low 10 afrs.. its safe....


and your hitting fuel cut because you have it set to +20 ....

setting to 0 or -10 for starters and see if you still get fuel cut...

 

[BoostBuddyGSX]

i had it at +0% corr. value at 19psi and it hit fuel cut. 18psi and +20% corr. value stopped it. and yea, i bought the injectors used, and the guy told me they were 700cc... i was too excited to stick 'em in that i didnt check part #s and such..

 

[talontd92tsi]

If you want to lean it out you need to take it to the negative side of the SAFC, your ECU is seeing 20% MORE airflow at +20. Your gonna run rich as hell like that and hit fuel cut sooner.

 

[knochgoon24]

The SAFC is an "Air Flow Controller". Your adjusting how much air the car sees. So for bigger injectors, you want negative numbers.

 

[zhjiln]

like the post above me... yeah you adding 20% with 700cc will make you hit fuel cut sooner... you are suppose to already start by doing the base compensation for those injectors .. they 55% bigger than stock... but the afc only does +- 50 ... thats why you dont want to use fuel injectors over 650cc ..... and with you having to -50 ... imagine the timing curve..

 

[BoostBuddyGSX]

ahhh ok i see... well, time to socket the dsmlink! thanks for the help guys!!

 

[BoostBuddyGSX]

I am also curious as to why my WOT AFR is a CONSISTENT and unchanging 10.2. There is never a deviation from that number, even with the following:

-different RPM ranges
-different boost levels (tried 10-20 psi)
-different gears
-different loads

I know that that the computer cannot so instantaneously adjust to keep the WOT AFR at 10.2. I also know that I shouldn't be able to maintain that AFR at 20psi as with 10psi, without any fuel modifications. And I know that it can never be so dang spot on consistent and unchanging with the above mentioned varying conditions.
So what's going on?

My AEM wideband is brand new and I get no error lights with it. The idle and cruising AFR's are stoichiometric, and it reads full lean during deceleration, so it's reading properly.

 

[jrohner]

The stock fuel maps are like 9.5 or something, so you're still leaner than stock, although richer than necessary.

 

[BoostBuddyGSX]

bumpety bump