Aem uego Gauge type problem?

[Big Al 389]

I just installed the AEM 30-4100, simple to install,but the problem I'm having is the afr is jumping back and forth between about 14.2 and 15.7 at idle and cruise.The sensor is in the rear o2 bung and the power and grounds are attached to the cig. lighter power and grounds!Does anyone have any ideas on what may be causing this?
Thanks...Al

 

[turboglenn]

it's just reading the AFR's in closed loop operation. Whne your motor is idling or cruising under light load, teh ECU takes signal from teh front O2 and constantly adjusts fuel flow to keep it as close to "stoichometric" as possible (stoich is around 14.7 and is the best ratio of air and fuel for a complete burn) And you wideband is just reading it.. no worries.

When you go wide open however, the thing should read 11.5:1 or richer, if it's anywhere in the 12' or 13's under full boost, let off the gas fast and re-tune if you can. If you have no means to tune, you'll need to get something to tune with or find out what's wrong with it. I can only guess since you haven't put your car's info in your profile.

 

[Big Al 389]

Dang Glenn your on the ball.So it's normal for it to jump around some at idle and cruise?But it should be constant a wot right?I have done any wot pulls yet,my fuel pump went out and I've got my old 190lph in for now, so with the 1000cc Pte's and just a 190 it would run out of fuel.I should have a new 255lph and frount mount here in a few days then I'll play!
Thanks for the quick response...Al

 

[CanadianTSi]

A 190 will pump all the Fuel you need for that 16g. But yes your car is constantly trying for 14.7:1 which means it will go slightly rich then slightly lean, back and forth in its pursuit of 14.7

 

[Big Al 389]

A 190 will pump all the Fuel you need for that 16g.

With 1000cc injectors will the 190 be enough?The flow charts that I found show that I needed a 255hp pump to keep up???Also I'm running e85,that is why I'm running the 1000cc's with the 16g.Not trying to question your info,just want to be safe and all.
Al

 

[GVR4592]

The 190 probably won't be enough for E85. I would skip the 255 as well and just get a Bosch 044.

 

[turboglenn]

EDIT: I didn't notice, but itf you're running E-85 that pump probably won't due, but i'll leave the rest of what i wrote just for enjoyable reading (yea right hah)

Well, the pump upgrade isn't "mandatory", but it's needed for the full potential of the injectors.

In your case you could still go wide open, just at lower boost levels. The pump is only going to "fall off" when those injectors are getting near 80% DC or higher. If your only on a 16g at say 15 lbs of boost, the injectors aren't going to get anywhere near 80% DC. When the 1000cc units are at 50% duty cycle they are pushing near the same amount of fuel as a set of 550's maxed out at 100%, which teh 190 is perfectly capable of handling). So in theory if you're only opening them enough for lower power operation (15-16psi on a 16g) this would put them only flowing 400-500cc's so the pump would be fine. But when you get to oping them up longer when more air is being pushed in and the boost is cranked then the injectors will empty the fuel rail before the 190 could keep it full. Just floor it for a minute and make sure that it "stabilizes" or at least goes to a richer number, it may still vary a bit due to mapping and the ECU changing it's mind about things too much I hate all the OBD-II related ECUs

Just go out, get in a decent gear for testing (i like 3rd) and make a long pull. You'll be watching the wide band anyway, so just let out if you see it go lean under WOT. A second or two of it being lean untill you let off isn't going to kill the motor it at those boost levels, or I would have probably destroyed a lot of motors while tuning. I'm proud to say i'v NEVER blown up a car tuning it or after the tune as long as the driver doesn't change anything. I did have a WRX that i tuned blow up at the track, but it was because his wastegate vacum line blew off and he was pegged on the boost gauge with a T66 turbo with a stock bottom end and tried to finish teh pass anyway.

I hope this makes some sense, I'm a bit off kilter right now, my medication is strong and i just got refills today after not having any for a few days

 

[Big Al 389]

Glenn,what's the best way to make pull with an auto?Ihave been just getting it up to around 40 mph and flooring it,kind of a pain though.I'll have to check into some other pumps before I order another one just in case I need to upgrade a little more or something
Al

 

[laserspeeddemon]

15.7 is lean for a closed loop on a factory tune.

I suggest using a voltmeter to find a fuse position that is powered only when the ignition switch is "on." And ground to the chassis somewhere (there are TONS of places for this). And see if this changes this changes anything.

**edit** Just saw the E85 too, I would suggest a fuel pump change as well.

 

[Big Al 389]

It's connected to the power and ground for the cig. lighter which are only on when the key switch is turned on.Do I need to power and ground it from somewhere else?
Al

 

[1gnasty]

sound like a lack of tuning to me

 

[Big Al 389]

Sorry I wasn't clear,I plan on putting 255hp back in,what I meant was that the 190 was just a temp.
It may be tuning,that was why I posted it here for advice,I just put the uego in yesterday and I've never had one before,so any help is good!
Al