accord_raffi

Ya so I took out my subs and amp the other day and i took it for a drive and noticed my AFR's were reading differently...I can't really figure out why they would change from subwoofer removal. Anyone have any ideas? The numbers weren't necessarily bad. Also, about a week after I got the diff numbers, my gauge started to read 14.8 and 14.7 at all times. At first i thought i had either a bad sensor or my pins were bent. Now i'm wondering if the change in AFR and the later readings of 14.7/14.8 are related. Maybe the two problems are completely separate and maybe they're not. I don't know a lot on electrical so help me out guys. ANY IDEAS?!

90sedan

If the car was tuned with the sub connected it was tuned on that specific amount of electronic load. And now with the sud removed there is less load, which will effect your a/f ratio.

accord_raffi

sorry too sound dumb but could you tell me how exactly the electronic load affects the amount of fuel injected by the injectors? I've never really looked at how the electronic connectors on the injectors work but i guess it would affect the connectors somehow?

98vtec

your injectors have different settings for different amount of electric load

search for injector battery offsets

accord_raffi

aw man i didn't tune my car myself...i should probably start reading on how to tune a car with Crome lol. that's what i used at DSG.

p.s. so you guys think the two issues are separate then?

Root of all Evil

[QUOTE=90sedan]If the car was tuned with the sub connected it was tuned on that specific amount of electronic load. And now with the sud removed there is less load, which will effect your a/f ratio. [/QUOTE

That's funny, I've never seen anyone tune a car with the system consuming 1kw. But other than that scenario it would not have any effect.

DOHC_16v

Removing the subs would only affect the AFRs in situations where the amp/subs would be drawing power when they were connected, If the ECU doesn't compensate for the power draw. Less voltage means the fuel pump and injectors get less voltage, but in your case it seems like you just have a bad sensor.
Are you using a wideband or an A/F gauge to monitor the AFRs? If you're using a A/F gauge, it will read 14.7 at all times if the sensor is dead.

rorik

If your alternator was adequate with the stereo system, the voltage will not change. The injector offset should not be applicable to this situation.
None of this makes any sense.
"Hold on, let me turn my **** up before you start tuning, I need to drop my system voltage to reflect how it's gonna be when I'm driving" see what I mean?
Something else is going on here..
Edit: Never mind, if your gauge reads 14.7 all the time, the sensor is bad..

postman

hell when i turn on my headlights i can see a difference on my wideband.

accord_raffi

alright well do the sensors read diff numbers when they are starting to fail? Perhaps the sensor was going bad which resulted in the changing of numbers, and the the sensor completely failed. are you sure it's not the electircal load on the injectors? so far a few ppl, as you can see, can seemed pretty definite on that.

BTW subs weren't on during tuning, which is why i didn't think the subs being removed sshould have affected the afrs...I suppose there could still be a draw from the ground though...maybe? I honestly don't know anything on electrical.

97grnrs

yes the sensors will read wrong if the foul out or go bad. ive seen it on my own.

rorik

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by postman &raquo;</TD></TR><TR><TD CLASS="quote">hell when i turn on my headlights i can see a difference on my wideband.</TD></TR></TABLE>

What is the difference? Maybe you do have a difference in the actual a/f ratio, not just in the gauge. After all, the headlights do put a load, albeit small, on the motor.

To the o.p., you said it reads 14.7 all the time, even under boost? That tells me the sensor is done..

accord_raffi

I'm guessing it's the sensor. Rorik, do you think that's the case given the other circumstances, or do you think it's related to the removal of subs and the AFR changing.

spark

And if it was the magnetic field on the fuel pump ?

Flashmn

Electrical interference is also a factor that can cause weird readings with inductance from different devices.

SPOOLINmatt

does the eld aid in adjusting for changes in the cars electronics system?

rorik

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by accord_raffi &raquo;</TD></TR><TR><TD CLASS="quote">I'm guessing it's the sensor. Rorik, do you think that's the case given the other circumstances, or do you think it's related to the removal of subs and the AFR changing.</TD></TR></TABLE>

I think the a/f hasn't actually changed at all, just the sensor has. I also think that the removal of the subs was entirely coincidental..but you know how the e-diagnosing goes sometimes..
I just don't see how the subs could have affected anything.
I don't know exactly how the eld works. I have been reading on it a little, I guess the alternator has different output levels, and the ecu switches it between them depending on the voltage level of the system? Pretty weird. I thought that the alternator just had a fixed output with it's own regulator. I'll be reading more on this..

accord_raffi

i should prob start reading it too, but i loathe electrical lol. lemme know if you guys think of anything. I'm hoping it's a coincidental event that happened

p.s. well considering i haven't had the uego sensor for very much time at all, i e-mailed AEM and maybe they can do something. that has to be replaced regardless

Civicman86

Electronic load does effect your AF. For instance in eCtune, which is what I tune with, there is a battery offset table. It basically is a correction table that adds/subtracts fuel depending on the voltage your car sees.

Your AF changes when the voltage changes becuase the injectors are electrically controlled (ecu ground the injector when it needs to open or pulse). As there is more/less load the injectors may 'lag' when pulsing, thus changing the AF at whatever part of the map your in.

This may not pertain to you as it usually is a small change that is really only noticed when daily driving (i.e. headlights on, radio, etc.). You never specified how much the AF changed so I didn't know if this pertained or not.

HTH


Modified by Civicman86 at 3:33 PM 9/19/2008

98vtec

accord_raffi

well now i can't even tell my afr cuz my damn sensor from AEM is fried. All the pins are straight like the should be. AEM better be sending me a courtesy one since this didn't even last 2 months...Yes, i followed all their instructions for install.

rorik

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Civicman86 &raquo;</TD></TR><TR><TD CLASS="quote">Electronic load does effect your AF. For instance in eCtune, which is what I tune with, there is a battery offset table. It basically is a correction table that adds/subtracts fuel depending on the voltage your car sees.
</TD></TR></TABLE>

So the a/f only fluctuates with system voltage is the battery offset table is off..

Anyone know if a peak and hold injector driver is affected the same way as a saturated or resistor setup by system voltage? (how advanced is the driver's control circuitry?)

98vtec

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rorik &raquo;</TD></TR><TR><TD CLASS="quote">

So the a/f only fluctuates with system voltage is the battery offset table is off..

Anyone know if a peak and hold injector driver is affected the same way as a saturated or resistor setup by system voltage? (how advanced is the driver's control circuitry?)</TD></TR></TABLE>

all injectors types are influenced by different battery voltages.

AFR will always fluctuate unless you have the means to control the AFR for different voltages.

SovXietday

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rorik &raquo;</TD></TR><TR><TD CLASS="quote">So the a/f only fluctuates with system voltage is the battery offset table is off..

Anyone know if a peak and hold injector driver is affected the same way as a saturated or resistor setup by system voltage? (how advanced is the driver's control circuitry?)</TD></TR></TABLE>

Yes, they are.

Most people don't realize that their fuel system is driven by their electrical system. Clean your grounds like an oil change!