2G Is my AEM wideband bad?

[brandynw93]

Hey Guys,

Trying to see if my AEM wideband is bad or if this seems normal as far as the cycling goes on the log.

This is from the first start of the day, just idling

 

[steve]

I can't say if the AEM WB is bad but your log looks like the tune is off.

If you assume that the WB is correct ATM it would seem that your very lean at idle and the fuel trim has maxed out without getting the O2 to switch like it should. Since you don't have a narrowband O2 to compare with there isn't much to compare with/to. What is your gauge reading at idle?

Please fill out a profile for this car.

 

[brandynw93]

I can't say if the AEM WB is bad but your log looks like the tune is off.

If you assume that the WB is correct ATM it would seem that your very lean at idle and the fuel trim has maxed out without getting the O2 to switch like it should. Since you don't have a narrowband O2 to compare with there isn't much to compare with/to. What is your gauge reading at idle?

Please fill out a profile for this car.

Just filled out a profile for the car.

The sensor itself really isn't even old, maybe about 4 months. Upon start up it will read very lean. 18-19 on the gauge. after a little bit of idling it will sometimes balance out and idle around 14-16. Although, during this start up period if the gas is pressed the car will choke for like have a second and then rev up. The car doesn't react that way If I slowly and gradually press into the pedal, only a quick press. After warming up i don't experience this behavior.

After warmed up and driving, sometimes the car goes lean when shifting from 1-2 and car becomes jerky for a couple of seconds before it balances out. During boost and WOT it drives great and AFR's read 12-13.

 

[steve]

Did I miss the mention of injectors in your profile?

 

[AWD-Tony]

Was it fine before and this just started happening? Has the car been tuned?

 

[brandynw93]

Did I miss the mention of injectors in your profile?

I forgot that detail . They are FIC 1220 Low Z Injectors

Was it fine before and this just started happening? Has the car been tuned?

It was fine for a real good while post tune. My tuner did mention that the Low Z injectors are not the greatest (old technology).. wondering if maybe they are becoming inconsistent now.

 

[AWD-Tony]

Car is on pump gas? Besides the fuel trims, AFRest and wbfactor being off, I don't really see anything that stands out. I would test the WB sensor by removing it, wrapping it with a rag soaked in brake clean and making sure it reads rich. Remove the rag and it should read full lean. Do this a few times, then calibrate the WB. If you still have an issue, I'd start looking into the fuel system. Could be clogged/sticking injector, clogged fuel filter, leak at fuel pump, check fpr.

As for low impedance injectors, I would disagree with your tuner. Many people still run them without a problem.

You should be logging MAFraw & battery. Under MAF Comp and Misc, uncheck "disable airflow smoothing w sd operation".

Do you have an old tune you can post that includes idle time?

 

[brandynw93]

Car is on pump gas? Besides the fuel trims, AFRest and wbfactor being off, I don't really see anything that stands out. I would test the WB sensor by removing it, wrapping it with a rag soaked in brake clean and making sure it reads rich. Remove the rag and it should read full lean. Do this a few times, then calibrate the WB. If you still have an issue, I'd start looking into the fuel system. Could be clogged/sticking injector, clogged fuel filter, leak at fuel pump, check fpr.

As for low impedance injectors, I would disagree with your tuner. Many people still run them without a problem.

You should be logging MAFraw & battery. Under MAF Comp and Misc, uncheck "disable airflow smoothing w sd operation".

Do you have an old tune you can post that includes idle time?

Car is on E-85. I will have to try the rag test.

I also want to double check my fuel pump because I just recently did a 2,500 miles road trip and at some points in the trip the Walbro Fuel pump whine got extra loud after several hours of driving. Maybe it's a little worn out now or something.

I'll try unchecking that box. To log the MAF and battery, is it just an option in link that I select?

This is my very first tune, so I do not have anything else

 

[AWD-Tony]

Pump could also whine from blockage. I recommend going through your entire fuel system. It seems to me that’s your issue. When you remove the pump, check to see if anything is slimy as ethanol can cause this.

To capture and display values, jump to 7:20

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[brandynw93]

Pump could also whine from blockage. I recommend going through your entire fuel system. It seems to me that’s your issue. When you remove the pump, check to see if anything is slimy as ethanol can cause this.

To capture and display values, jump to 7:20

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Fuel system seems to be fine, I'm getting the right pressure at the FPR, fuel filter is brand new, and swapped fuel pump.

Did the brake clean and rag test on my WB sensor and it checks out fine. It goes full rich and full lean.

The alternator is new and the battery is reading good voltage when car is off and on. Although, while idling, when I press on the gas to rev it the cluster lights flicker quite a lot. When the revs come back down the AFR's drop down pretty lean "18-20" and then gradually rise back up.

Battery voltage also drops from 14.2 to around 13.8-13.9 when reving as well. I'm guessing something is robbing power?

 

[AWD-Tony]

Fuel system seems to be fine, I'm getting the right pressure at the FPR, fuel filter is brand new, and swapped fuel pump.

Did the brake clean and rag test on my WB sensor and it checks out fine. It goes full rich and full lean.

The alternator is new and the battery is reading good voltage when car is off and on. Although, while idling, when I press on the gas to rev it the cluster lights flicker quite a lot. When the revs come back down the AFR's drop down pretty lean "18-20" and then gradually rise back up.

Battery voltage also drops from 14.2 to around 13.8-13.9 when reving as well. I'm guessing something is robbing power?

Just the cluster lights flicker? Are headlights and other lights doing the same thing? When you let off throttle, the injectors momentarily turn off via the idle switch (believe it's under 1,500 rpms) thus going full lean for a second or two. This is normal.

 

[chrysler kid]

You can test resistance on pins 2 and 5 of the oxysensenor plug to check to see if the sensor is bad. The resistance should be 3 ohms, if it shows 1.7 ohms then 0 the heater element is bad

 

[brandynw93]

Just the cluster lights flicker? Are headlights and other lights doing the same thing? When you let off throttle, the injectors momentarily turn off via the idle switch (believe it's under 1,500 rpms) thus going full lean for a second or two. This is normal.

yeah, cluster lights flicker a lot while headlights might flicker very little.

yes, I get what you're saying with the injectors, but this is a bit different as it goes lean after letting of throttle and it stays lean. Rpms bog down for a while and it slowly will balance out a bit but most times only to 16-17ish afr.

 

[AWD-Tony]

yeah, cluster lights flicker a lot while headlights might flicker very little.

yes, I get what you're saying with the injectors, but this is a bit different as it goes lean after letting of throttle and it stays lean. Rpms bog down for a while and it slowly will balance out a bit but most times only to 16-17ish afr.

What's the voltage when lights flicker? Does it still flicker when you slightly raise rpms?
I've had a similar issue with my WB. It went full lean only when using NLTS. Changed the sensor and it was fine so it I wouldn't be surprised if it's a lazy sensor.

 

[brandynw93]

So just to update here:

I currently have another AEM WB on the way which I will swap in to see if that solves my problem.

As far as the fuel system goes:
I have tested the FPR, Fuel pressure is correct at idle and when on throttle. (pressure holds and doesn't drop). I removed the vacuum hose while car was running and the gauge needle did move up several psi. The vacuum hose had was dry.

I also removed fuel injectors and cleaned them, they didn't look clogged at all and sprayed very well.

Replaced my Walbro 255 with a new unit. Fuel filter is also brand new.

My battery is in good shape. Alternator has been swapped (for the second time) and the dash/headlight flickering has stopped.

I inspected the ECU and everything looks great. No leaking capacitors.

So I'm kind of stumped. The car takes a long time to start up. I have to turn the key a bunch of times to build up enough fuel to start the car. (fuel pump primes 2.5 secs when key turned). When the car starts the AFR gauge will initially be at 14-15 but then gradually go down to 20 within several seconds.

I still feel like this is fuel related, but everything seems to be fine??

 

[AWD-Tony]

Test the resistor before and after it gets hot. There's coolanttempinjadjust in DA but that would just be a bandaid. Might be a good idea to get those injectors cleaned and tested if everything checks out.

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