Tuner Can't Tune Car

[tdstuart]

I'm going to look at the MAF period numbers and see if they fit that intake. Hopefully today.

I'm assuming the fuel trims are what is out on the non-Lund tunes? Correct?

I only glanced at your logs but the cam timing looked good for your comp cams from Lund. They were stock from the other tuner you sent logs for.

I haven't looked at all the logs you sent so I may not see the discrepancy from Lund yet.

I didn’t send you any of the logs for the “rebuilt” tune they sent me that they claimed was the same. All the Lund logs I sent you should be on my tune that I had since my old motor that was consistently the fastest.

Fuel trims, injector duty cycle, internal torque calculations, maf data are all off on my new tuner. If you look at the torque calcs for some of the logs the car thinks it’s making 900hp lmao

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[K4fxd]

I don't see how it's possible PMAS and JLT share the same transfer functions.
There's more to it than the 120MM MAF diameter.

They should be close enough that I should be able to see if it is in range so to speak.

didn’t send you any of the logs for the “rebuilt” tune they sent me that they claimed was the same.

OK that saves me some work and math.

 

[tdstuart]

I don't see how it's possible PMAS and JLT share the same transfer functions.
There's more to it than the 120MM MAF diameter.

They aren’t exactly the same from just looking at my stft and ltft gauges they are a few percent different

 

[GregO]

They aren’t exactly the same from just looking at my stft and ltft gauges they are a few percent different

I’ve validated many mass flowmeters in my trade. Anything outside of +/- 1% is a hard FAIL. Those that manipulate mass flow readings to achieve a desired result are going about it the wrong way.
I could be wrong but I’d think this also applies to modern Mass Airflow ECU managed internal combustion engines.

 

[engineermike]

@GregO you’re right but using our methods to “calibrate” the maf it gets pretty sloppy. For example I was driving myself nuts trying to get SD fuel trims under 5% on my Roush truck. Then I logged a brand new stock maverick and its fuel trims were regularly 8% and sometimes over 10.

 

[GregO]

@GregO you’re right but using our methods to “calibrate” the maf it gets pretty sloppy. For example I was driving myself nuts trying to get SD fuel trims under 5% on my Roush truck. Then I logged a brand new stock maverick and its fuel trims were regularly 8% and sometimes over 10.

Am I understanding correctly that +/- 1% is too tight for automotive Mass Airflow systems ?

 

[WildHorse]

They aren’t exactly the same from just looking at my stft and ltft gauges they are a few percent different

That's cause you can't use the JLT tune with a PMAS. Well, you can, but things will get wonkie. Also, the PMAS DOES NOT like any turbulence whatsoever, so you need it OUT of any airstream.

 

[K4fxd]

Am I understanding correctly that +/- 1% is too tight for automotive Mass Airflow systems ?

Ford allows 10% as a good calibration. There are too many variables in mass produced engines to make it better than say 5%. I have mine calibrated to 1% but it took me months of logging at all times of day and night and all kinds of weather conditions. I had maybe 600 logs that I then averaged to get a cal. This got me to the 1 to 2% range. I then logged more and averaged those numbers into what I already had and got it to 1%.

Now this assumes the fuel injector data I have is correct. My car runs like a top however.

I've used this period table on other cars and it doesn't get 1% on those cars. This is why some cars won't run properly on a tune that "works for thousands of cars"

The ECM uses the MAF data plus the injector and O2 sensor data and figures out lambda even with the built in error.

 

[tdstuart]

That's cause you can't use the JLT tune with a PMAS. Well, you can, but things will get wonkie. Also, the PMAS DOES NOT like any turbulence whatsoever, so you need it OUT of any airstream.

Car shows less than 10% fuel trims most of the time and only a few percent at wot so I feel comfortable running it

 

[tdstuart]

Yes, there are specific plastic thread lockers by the major brands.
Search around.
Locktite 425 is designed for metal to plastic.

Will Permatex 80632 work?

 

[K4fxd]

My guess is whatever you used is now permanent. The Teflon tape is always safe. Just don't use too many layers on plastic.

 

[tdstuart]

My guess is whatever you used is now permanent. The Teflon tape is always safe. Just don't use too many layers on plastic.

Nope it came right off with break clean. My problem with the tape is there is like 3 total plastic threads that don't look super good as it is and I don't want to strip them.

 

[K4fxd]

Unless I need to take it apart I'd use JB plastic weld epoxy and forget it.

 

[GregO]

Will Permatex 80632 work?

Nope it came right off with break clean. My problem with the tape is there is like 3 total plastic threads that don't look super good as it is and I don't want to strip them.

Yeah it’s to bad that area wasn’t beefed up in thickness for the NPT thread. I have reservations with standard pipe thread dope for what you’re trying to accomplish.
Loctite 401 also works well on metal to plastic.
Super Glue gel, the two Loctite products I mentioned are Cyanoacrylate,

 

[tdstuart]

T

So is that a no haha. Maybe ill just follow K4fxd suggestion and use jb plastic weld. I don't see a reason for it to have to be removed and I have some laying around.

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