Tuning question/engine maintenance

[Bluemustang]

The car seems to be running better today after doing the KAM reset.

When I took off the intake tube last night - it looked fine. I couldn't really see anything that could disrupt airflow.

Maybe I should leave it alone and tell the shop to return the new intake tube?

I don't know how to check AFR being that it is a flex fuel tune. I am assuming that will not work.

Can I take a datalog and have one of you on here take a quick look? Just to make sure everything is okay I mean.

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[dbranger94]

If the car is running good and the AFR is 14.5-15 at idle on 91-93 pump gasoline, it should be fine. I always go by the AFR reading in the information display in the dash, it actually reads somewhat correctly with E85 as well. The readings from aftermarket tuners (IE nGauge, perhaps SCT) isn't as accurate. Their AFR values are calculated based on Lambda instead of reading the actual sensor voltages. Lund racing actually confirmed this to me with their nGauge.

"The nGauge like I said is an inferred value and yeah it goes off lambda. I don't monitor it on the ngauge though. I would just go off the dash"

 

[Bluemustang]

If the car is running good and the AFR is 14.5-15 at idle on 91-93 pump gasoline, it should be fine. I always go by the AFR reading in the information display in the dash, it actually reads somewhat correctly with E85 as well. The readings from aftermarket tuners (IE nGauge, perhaps SCT) isn't as accurate. Their AFR values are calculated based on Lambda instead of reading the actual sensor voltages. Lund racing actually confirmed this to me with their nGauge.

"The nGauge like I said is an inferred value and yeah it goes off lambda. I don't monitor it on the ngauge though. I would just go off the dash"

1. Isn't 93 pump gas (E10) supposed to be 14.1 stoich? I think E0 pump gas is 14.7.
2. This was not what Lund told me. They told me when I read them my AFR on E85 that the reading on the dash gauge was not correct because the dash gauge was configured for 14.1 stoich and basically to ignore it.

I can tell you this. Before I removed the intake and put it back together and did the KAM reset I was seeing 12.8-13.2 at idle. After - 13.8-14.2

Perhaps the funny business with the intake tube shocked the computer and it needed the KAM reset.

 

[dbranger94]

This is gonna be difficult to explain and I'll probably mess it up, but...

The stoich point of a fuel and the AFR the computer is set to target are two different things. It's easier to think of it in Lambda, where you are always trying to target 1. It takes more E10 (per volume of air) to get to a Lambda of 1 than it would E0. Likewise, E85 has to be ran much richer than either of them. Ideally there shouldn't be any oxygen left after the combustion process (IE 1 Lambda). The ECM doesn't use AFR because it's an arbitrary number that is only 14.7:1 in a laboratory. Real world humidity, temp, etc. makes this number change. So, the ECM uses the O2 sensor to try and maintain a Lambda of 1, no matter what fuel is in the tank, by adding or subtracting fuel.

As far as gauges go, most gauges read the Lambda value from the ECM and assign an AFR value accordingly. For instance, some may use 14.7:1 = 1L, other gauges/people/manufacturers may use 14.1:1 = 1L. Unless you know for sure it's better to ignore this number all together. However, I find that when I run E85 my nGauge reads 14.5-15AFR and my dash reads closer to 10. So, I choose to trust the dash more. YMMV.

 

[dbranger94]

You should be able to pull lambda from the ECM using the SCT. I know my car has always been tuned since the first week I had it and it's always read 14.5-15 AFR at idle and bounces a little. I assumed that Ford used 14.7 stoich, that may have changed. Lambda has always been very close to 1. If you want to log a 3rd gear pull from say 30 to however fast you are comfortable with, I'd be happy to look at the log.

 

[EFI]

I assumed that Ford used 14.7 stoich, that may have changed.

For uses 14.08 stoich in the factory tune, which is why the ngauge readings are different than in the dash and thus inaccurate.

 

[dbranger94]

For uses 14.08 stoich in the factory tune, which is why the ngauge readings are different than in the dash and thus inaccurate.

Thanks, that's good to know.

 

[Bluemustang]

You should be able to pull lambda from the ECM using the SCT. I know my car has always been tuned since the first week I had it and it's always read 14.5-15 AFR at idle and bounces a little. I assumed that Ford used 14.7 stoich, that may have changed. Lambda has always been very close to 1. If you want to log a 3rd gear pull from say 30 to however fast you are comfortable with, I'd be happy to look at the log.

Thanks dude. So presumably I can look at lambda and know that it is very close to 1 I am good.

I will get try to get a datalog tonight and upload it here. Can you tell which format the log needs to be in for me to upload it here? Can I upload .csv files?

I'm using SCTX4 and LiveLink Gen II.

Thanks brother.

 

[dbranger94]

.csv files are the most common. You can open those in Excel. If it won't upload here, you can PM me and I'll give you my e-mail. You could also try zipping it up and uploading it too.

Also, if you can include a few seconds of just normal 55 or so cruising that would be helpful as well.

 

[Bluemustang]

.csv files are the most common. You can open those in Excel. If it won't upload here, you can PM me and I'll give you my e-mail. You could also try zipping it up and uploading it too.

Also, if you can include a few seconds of just normal 55 or so cruising that would be helpful as well.

Awesome dude! I will do that for sure. If I have any problems I'll PM you for your email.

Thanks again :cheers:

 

[Bartly]

Awesome dude! I will do that for sure. If I have any problems I'll PM you for your email.

Thanks again :cheers:

Last I recalled the forum won’t allow an upload of .csv, but you can just rename it to something like .txt and it will upload fine. Whoever wants to open it just has to download it and rename it back to .csv. Just thought I’d pass the info along.

 

[Bluemustang]

Ahh, unfortunately the file is too large to upload. Drats.

 

[Nuked]

datazap.me

upload it there

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