vafc crap new problems
 

my vafcII isnt letting me turn down my injectors, i had 450's in and had them tunrned all the way down and it was running super rich, 10:1 now i put 390's in and its still doing the same thing, ive double checked the wirirng and its dead on. vacumm to the map is good, no cel's afr's are still 10.0 at idle and its not the wideband cause its so rich its puffin out some smoke.lol im not sure why its not turning them down ??

Re: vafc crap
 

is your signal set right?

Re: vafc crap
 

Rock an FMU

Re: vafc crap
 

Have your grounds spaced out properly? Maybe it's just a bad unit. :P

Re: vafc crap
 

---- yourself :D

signal is set and down and to the right ( cant point it up and to the right cause then it reverse's my throttle percentage)
i thought this to but if i change it like i said it changes my throttle %

Re: vafc crap
 

mayby just got a bunk unit then.

Re: vafc crap
 

not likely, ive never heard of that, but im sure its possible

Re: vafc crap
 

alright well i kinda fixed the problem, my in outs were switched which i thought i checked but i must have just checked the connection and not the wire routing :S now it starts and runs fine no smoke. but after running for like 30 seconds it drops to rich then to lean (wtf) and then my car will die. im not sure if its cause i dont have a stock o2 sensor hooked up or something ??

Re: vafc crap
 

Only at idle right? I remember the last time I used an afc I had to turn the 500-1000 rpm range up to around -28 or so to keep it idling...injector latency from the 450's was too much with the factory ecu settings.

Re: vafc crap
 

i havent been drivin it due to the fact i cant even get it to run right in my garage..lol. im not sure why it would go to 10:1 then a second later jump to 16:1 :S then die ? wtf im not throwing anycodes but i dont have a stock o2 sensor hoooked up, thats the only thing i could think of

Re: vafc crap
 

If anything that would make it run a hair bit richer. I used to do that as an old trick to squeeze a little extra fuel...would disconnect the o2 and let it pop a code for it on my old pg7's and d16's ;D

Re: vafc crap
 

lol, werd. my car isnt throwing any code's what would make it jump like that ?? fuel pressure maybe ??

Re: vafc crap
 

Careful.

Pre-OBD and OBD0 immediately ignore O2 upon a quick enough change in MAP or RPMs. OBD1/2 will continue to respond to the O2 until TPS goes over 4.0 volts. Further, OBD1 is really good for rich stumbling part throttle if you don't have an O2 sensor hooked up... the ECU sees 0 volts coming from the ECU, ASSumes lean, and starts dumping fuel.

Re: vafc crap
 

Unplug o2, engine warmed, 6-7sec of sustained decel injector cutoff, and an OBD0 will CEL the o2 like clockwork. Dont know if obd1 error checks the same.

vafc's look cool at night, while FMU's rape your pump and get the job done. >:D

Re: vafc crap
 

obd-o nmo cel

Re: vafc crap
 

Hmm...maybe that's why my old trick used to seem a little doggy at first and then take off like a raped date. I always thought the cel would make it read off the timing and fuel maps 100% of the time that way...good info to know. I rarely dabble in the obd1 world just yet, or at least in the way it functions, so the obd1 info is def. good to know.

What's your fpr set at anyway? Could be a bit high. Never seen someone have such a weird issue with an afc before :l

Re: vafc crap
 

i think my fuel pump is shot but i dont see how? maybe from when i had the wires hooked up wrong and the 450's weren't tuned down, prolly put to much stress on the stock pump and blew it or something, i hear it turn on but no fuel pressure. i could be out of gas to though :P lmfao

Re: vafc crap
 

ok i was having the same problem but had to take my ---- off to drive it daily. but my fuel would not be corrected by the ecu. im guessing i had it wired wrong. could you let me know thrue pm with map wire to hook it up to. i mean the pin# and maybe how the grounds go on and where. thanks. i looked everywhere and got 3 different answers and none of them have worked. lmk. thanks

Re: vafc crap
 

Apexi has a website that contains the definitive wiring diagrams for their sleazy hacks.

Re: vafc crap
 

i know but thats only fro obd-1 and bd-2 cars. ill just try tohe last wire i was told to try. hope it works

Re: vafc crap
 

i just switched the white and yellow wires some kid on h-t said that the book was wrong and apex never released the info,l i did it and it worked fine, but then my car went to rich then lean and died, now it has no fuel [pressure and wont start. i'm either out of gas or fuct my fuel pump by running it without the injectors tuned down. i have tomorrow off ill look into some more then

Re: vafc crap
 

yay i got it to work today and just in case anyone was wondering its c11 for the map signal wire. i forget which wire i put on what side of the harness but it worked. turbo time. hahaha.

Re: vafc crap
 

good news

Re: vafc crap
 

lmao! Thats wild!

Re: vafc crap new problems
 

well i have the 390's in now(gray tops) tuned down 50% from like 1000-3000 on low throttle to have a normal afr at idle but im still running pretty rich, wide band fluxuates (spl) from 12.5:1 - 13.2:1 at idle, that seems pretty rich for idle, fuel pressure is at 40 on the rail and 35 on the return is it normal for it to run so rich at idle ?? or could it possibly be that my wideband is place to close (about 10 inches from exhaust housing) ? thanks for any help. p.s. also wondering if the gray top dsm injectors are high impendence or lo impendence

Re: vafc crap new problems
 

Your wideband placement is fine, mine is about 5 inches from the exhaust housing.

Re: vafc crap new problems
 

Pretty sure 390's are low imp. so resistor pack is your friend. :P

Re: vafc crap new problems
 

factory honda resistor box is installed it obd-o mpfi stock clips

Re: vafc crap new problems
 

also what should the v/t unmt be set at if vtecs at 5000 ??low % ? and high % ?

Re: vafc crap new problems
 

Stock pr3's are usually around the 45-4600 mark, so I really wouldn't bother with a unmatch setting if you set it at 5000. If it presents a problem you'll see your wideband go rich from 4600 to 5k and then go normal. You can dial it out then if it really bothers you. Just out of curiosity, how far did you retard the timing at the dizzy? Might have an incomplete combustion if it's too far retarded making it seem like it's still rich.

Re: vafc crap new problems
 

good guess but i tried that today :D my guess's are

~ bunk afc
~ need too switch my two outer tps wires and change the throttle setting to northeast instead of south east
~ bad map sensor but not throwing code ??
~ something to do with car not reading a stock 02 in closed loop mode ??
p.s. i dont have a stock o2 sensor hooked up just the wideband, could this be making it run so shitty in closed loop mode??? ive asked this a few times but no one really said if its a problem

Re: vafc crap new problems
 

well i changed the tps wires and set the throttle at hortheast and im still getting the same problem. it leads me to this conclusion-
~ car doesnt have a o2 sensor hooked up so when its in closed loop mode it cant get a reading which would make it think its running lean so the ecu richins the ---- out of it to compinsate for that. is there any way i can just splice the power for my wideband into the ecu pinout and it would read off the wideband ??? or no becouse the ecu is setup for a narrow band reading ?? thanks

Re: vafc crap new problems
 

Can't do that because the ecu is set to read a narrowband input (i.e. rich or lean, nothing in between)

If your wideband can emulate a stock O2 output then it will work.

Re: vafc crap new problems
 

or you can solve everything with $23 of basemap and a zif connector ;D

Re: vafc crap new problems
 

say "---- it" and chip that ----. not very expensive, i got like the most ghetto setup, but i still chipped my ECU

Re: vafc crap new problems
 

Here's food for thought...what about the fact the ecu is missing BOTH o2 inputs? Don't forget pr3's have a primary and secondary o2 for optimum fuel efficiency.

Re: vafc crap new problems
 

Yah, C8 and C16 FTW!

Re: vafc crap new problems
 

I know how much you *hate* chipped ecu's, but the way things are looking for you it would be much easier to toss a zif socket in that pr3 and drop BRE in it. Not to mention a bunch of cool little toys in the program that I KNOW you'd enjoy ;D

Re: vafc crap new problems
 

se nither is hooked up ... would this cause a problem ??

Re: vafc crap new problems
 

Probably some type of problem. Could try dropping a stock 1-wire o2 sensor in and connecting both C8 and C16 to the sensor and see what it does.