zojirushi

I just put in my joe p boost controller and my max boost is .5 bar. Now a cel comes on whenever i hit .5 bar. my settings on my afc are -35% across. If i take out the boost controller and go back to .45 bar, no cel at all. what gives??? i've seen people use -35% with 10 psi of boost with no problems. Any ideas? TIA

Evil EG

well what cel is it throwing?

Sipower99

probably map sensor. i think the ecu is sensing boost.

rbf351

i'm using the afc hack as of last night

i'm not using a boost controller and not going over 3-4lbs of boost yet, but i haven't gotten any CEL's yet

the only thing is it runs really rich

brcivic411

if it IS map sensor, then try setting it for -40%. what injectors are you running?

zojirushi

i'm running 370's
my fuel pressure at idle without vacume is around 50 psi

zojirushi

my fuel pressure is high enough... plus i'm at -35% already. .5 is only about 7.6 psi. This makes no sense

TurbothisLS

370's are too small
you have to run 450's with the hack.
you need to run 450's and lean it waay out so the voltage is low.

zojirushi

listen, i've increased the fuel pressure enough so that my injectors are running at
400cc's. Thats not my problem.

swrdply400mrelay

You have it at -35% all the way across the fuel map right? I'm guessing you're not using a FMU? It would seem like you would have to subtract less fuel as the rpm's go up rather than have the same fuel trimming across the rpm range. Because you are boosting, you will have to add more fuel once the turbo spools up and begins to boost. So try subtracting less fuel (ie adding more fuel) as the rpm's go up. Also pull the code for the CEL so you know exactly what the problem is. If this makes sense, hope it helps. If it doesn't, then ignore it.

zojirushi

i wish someone understood my problem...........
i'm not running lean. my fuel pressures are pretty high and i'm cutting the fuel with the afc. My problem is why does the cel come on when i hit .5 bar? I've seen ppl use up to 10 psi with -35 % . Why the hell would .5 trip a cel??????

zojirushi

what code will the ecu throw if it sense boost? guess i'll check my code just to make sure. it wouldn't make any sense for it not to be this problem tho.


[Modified by zojirushi, 11:13 PM 12/19/2002]

zojirushi

::sigh::

i do understand how the afc hack works... damn
i don't want to cut any more fuel because i'd have to increase the fuel pressure more. I'm already at 50 psi at idle. Don't think my fuel pump can handle anymore. But like i said, i'm at -35%, i've seen people run 10 psi with -35%. I'm only running about 7.5 psi.

Mr.DC2TurBo

Hey man, I know how you feel b/c I'm also running into the same problems. I just recently boosted my LS (.45bar) with 440cc injectors and an afc hack. My fuel setup consist of aem fpr and intank fuel pump. I'm throwing a cel but I'm just too lazy to check it right now mostly b/c of the freaken cold weather. Are you getting a really rich smell through your exhaust? When I did -35 at idles my exhaust fumes start throwing out black crap if I rev it a few times. My installer recommands me to keep it around -50 to -45 around 1-2k and start making it richer as the rpm gets greater. Let us know what kind of setup you are running, but chances are you will need it dyno tune to get your af readings adjusted. Are u in NJ b/c I'm in Philly so maybe we can meet up some where to get our cars dyno tune.

T-sohctec

:::sigh::::
no you do not know how or why the afc hack works.

People are not primarily using the afc hack for fuel reasons, they use it to fool the ecu.

If the map sensor is sending a signal to the ECU saying there is 8 lbs of manifold pressure, the AFC unit intercepts that signal, cuts it by a given percent and sends it to the ECU. If your AFC isn't cutting the signal down enough then your ECU will see someething above atmosphere and throw a code. Which is what is happening.

You can either keep driving around with a code.

or accept the fact that you where wrong and just subtract some off those bars on the controller.
good luck

zojirushi

anyone know the code for when the ecu sees boost?

maybe my afc is busted... because -35% is good enough for .5 bar. There was some formula for that but i forgot it.
[Modified by zojirushi, 12:38 AM 12/20/2002]


[Modified by zojirushi, 12:42 AM 12/20/2002]


[Modified by zojirushi, 12:43 AM 12/20/2002]

Daniel

maybe your wiring is a little loose somewhere? I've read through all the posts, but maybe I missed it or something; have you actually pulled the CEL? you keep asking what the code is for when the ECU reads boost, but if the CEL is lighted up, just jump the ECU and see what's up. it only takes like 5 minutes to do. or did you already do that?

EDIT: oh, i see it now. You said you'll get it tomorrow. Well, post back what the code is. I'm sure someone will pinpoint the problem once they know the CEL number.


[Modified by Daniel, 5:56 AM 12/20/2002]

swrdply400mrelay

Ok these are typical fuel settings for the AFC hack on a Civic (which stock fuel injectors are 240cc):

(440cc)
1-4k -40%
4.5k -38%
5k -36%
5.5-7k -35%

(370cc)
1-4k -28%
4.5k -26%
5k -24%
5.5k-7k -23%

Also, I would turn down the fuel pressure. When my fuel pressure was at 50psi at idle, I threw CELs; particularly 1 (primary O2 sensor) and 45 (too rich/lean).


[Modified by swrdply400mrelay, 6:02 AM 12/20/2002]

ITR981002

yup, what he said. while your 370cc injectors are plenty big to provide enough fuel for .5bar, you need at least 450cc injectors to allow you to cut enough voltage from the map sensor (by leaning things out ~40%) so that you won't throw a code. Sell your 370s, get some DSM injectors and a resistor box and you'll be