Just some quick questions on AFR gauge.

[Skarkull]

I did a search but I couldn't find any info.

I have the AEM wideband, and I'm seeing 18:1 afr at idle. Now my fuel pressure is good, between 25-30 psi. Car sounds like it is running good, but my gauge is peaked out at 18:1. Anyone familiar with the AEM's and what could be the problem?

-James

 

[702GT]

Have you done anything to the car? Did you just install this wideband? Need more info!! My buddy's AEM pegs out lean as well at idle, but he has massive overlap in his cams, so it reads lean because of the fresh air getting into the exhaust.

If you've had this wideband for a bit, and woke up one day to find it's lean at idle when it ran fine the night you parked it, might be a good idea to get the O2 checked and maybe borrow a friends real quick to verify your AFR is ok.

 

[Skarkull]

I have a saleen s/c tuned by JDM, with comp cams 127300's and supporting valve springs. Pypes LT headers, custom catted H-pipe, and a Techco 100mm MAF. O2 sensor is installed in front of the cat about 6"-8".

 

[702GT]

Great info, but not related to what I asked lol. Have you had the wideband in the car for a while and it just now started saying you're lean at idle? Or is it a new addition and shows 18:1 at idle. Does it look like it reads correctly during normal cruising? Have you done any WOT sessions, does it read according to what your tuner says your AFR should be? Do you have anyone locally that you can borrow a wideband from or a dyno shop that will check your AFR against your gauge?

If the wideband has been on the car for a while, it may just be time to replace your Wideband O2. But I'm more curious to know if your wideband is reading your cruise AFR or WOT AFR correctly. If it reads correctly under those conditions, I'd be more worried about the engine than the wideband. I know N/A you can get away with a lean condition at idle for a long time, at least long enough to get it fixed, without doing damage. But a FI motor, I'd imagine the IAT's are high even at idle, which makes a lean condition more damaging. Not that I know jack about FI motors, I'm just making an educated guess that FI motors aren't as forgiving as N/A motors when it comes to being lean.

Tell us about that wideband! Borrow a friends or see your local dyno for a AFR check. Lean is mean... to your pistons and rings...

 

[Skarkull]

I just installed this wideband, it is brand new, but it might be a voltage issue. Turns out I have a bad alternator. I'll have to put more info out once I get this problem fixed.

 

[Skarkull]

UPDATE: I got the alternator fixed, there is no power issue now. However, my wideband still says around 18:1 at idle and 16.5:1 when cruising. Fuel pressure shows 25-30 at idle, and slowly build pressure with RPM's.

I just did this install on the wideband, and I'm getting error lights but I mean come on, there is no way I wired it incorrectly. I wired it just the same as the others.

Any suggestions?

-James

 

[94tbird]

is it before or after the cat?

 

[Skarkull]

is it before or after the cat?

Before 6"-8"

 

[702GT]

What kind of error lights?

 

[stkjock]

shot in the dark, you calibrated the sensor before you installed it?

 

[Skarkull]

shot in the dark, you calibrated the sensor before you installed it?

There is no calibration for the AEM.

What kind of error lights?

I'm getting 4 error lights, but according to the AEM pamphlet that came with the kit, 1-6 means wiring. I have the red wires ran straight to the battery with a fuse, the pink wires are ran to the SJB and using a add-a-circuit on a key on hot circuit, the grey is ran behind the light dimmer switch to the white wire with the black line. Finally the black is ran to ground.

-James

 

[702GT]

I will look at my buddy's AEM tomorrow and check his wiring against what you listed. I don't think he runs the dimmer switch. 12v constant and 12v key-on are pretty straight forward, but grounds can be picky sometimes depending on location. There's 2 15mm(I think) bolts right behind the driver and passenger trim panels (the ones that are push-clip trims for the center dash on the right and left of the stereo and A/C controls) those are what I use for all my interior grounds, mostly because they are nicely hidden but easily accessable.

Anyways, I'll check his wiring against what you wrote and get back at ya here to confirm. Also, might be a good idea to double check your wiring connections to make sure you don't have a loose crimp/splice, unless you soldered the wires. Considering you're about 2-3 points off a "normal" AFR reading, I almost want to say it sounds like you're running in 10v mode instead of 5v mode. My Dynojet Wideband 2 has a switch on the back of the gauge for 5v and 10v (i think it says 10v..). But when I switched it to 10v mode once, I think it read 2 points richer, can't remember. I'll try switching my gauge to 10v mode and see what it reads. It's really easy to get at since I have it in a vent pod... unfortunately when I launch from 6k it also pops out of the vent pod a little sometimes lol. If I could get my 60' down to 1.6 or 1.5 I'm pretty sure it would launch clear out of the pod LOL.

 

[VTXFrank]

You sure you do not have an air leak at the O2 sensor bung hole? I had this exact same issue on one of my previous cars and the damned O2 sensor that came with the gauge was leaking air the first time, I cross-threaded it I guess, and the second time I had this issue, the O2 sensor was bad right out of the box. It would help tremendously if you could trouble shoot the system using a quality digital multimeter. If the sensor is bad, it will show in the voltage check.

 

[Skarkull]

I keep getting inconsistant values, hell my boost gauge said I was running like 15lbs. yesterday, but it ran at 0 lbs at idle and I know I should have vacuum at idle. My fuel gauge seems to run correctly and consistantly. I'm pretty sure it has to be a wiring issue. Maybe when I crimped my power lines to the single source line I didn't get good contact. I'm going to redo the wiring and see what happens. I also had to extend my fuel pressure and boost sensor wires because they were not long enough. However, I don't seem to have problems with the fuel pressure, so I'm going to check those splices where I made the wires longer. I'm sure it has to be a power source issue, or maybe a ground. Sometimes the boost gauge turns off completely, so I think it might be the 12v key source.

 

[702GT]

You have an electronic or mechanical boost gauge?

 

[one eyed willy]

 

[Skarkull]

electric

 

[Skarkull]

Willy... thanks for the info. That is good shit!

 

[dmhines]

There is no calibration for the AEM.



I'm getting 4 error lights, but according to the AEM pamphlet that came with the kit, 1-6 means wiring. I have the red wires ran straight to the battery with a fuse, the pink wires are ran to the SJB and using a add-a-circuit on a key on hot circuit, the grey is ran behind the light dimmer switch to the white wire with the black line. Finally the black is ran to ground.

-James

Not sure what AEM you have but mine just has a ground and switched power that needs to be hooked up. plug in the O2 sensor and you are done. I have a UEGO.

 

[Skarkull]

This one http://www.aemelectronics.com/wideband-air-fuel-gauge-8-5-to-18-1afr-with-analog-face-770