RWTD - I took your suggestion on MAF only CL

[mowton]

I realize Mustang does it, but the PCM programing from our Gen 3 vehicles and Mustangs must be different. Taking the VE out of a Gen 3 vehicle would most certainly alter the equations that GM embedded in our vehicle brains. I assume, Mustang altered their equatiuons to take into affect the MAF only approach.

Here is a link which talks alittle about it and it seems to infere the PCM is programmed to operate that way, not just table adjusted.

http://www.allfordmustangs.com/Detailed/583.shtml

This is interesting

Ed M

[RWTD]

Ford actually has what's called "Load w/ Failed MAF" tables (the '07+ GT500s do not, and it's a much better strategy on how they "predict" the fueling, and it is expected Ford will go over to this in the future). This table is used to anticipate aircharge events, as well, so it's not just used if the MAF fails. You can completely eliminate this ability from the Ford pcm, tho it's not suggested from a "calibrator" standpoint. I'd guess that 99% of tuners do it (disable it), however, as it saves them time, and of course some are just ignorant [I don't mean that in a bad way] as to what these tables do).

[Ryan L]

What actually happens with the Gen 3 if the MAF 'fails' and Dynamic Airflow disable is set to 0 RPM?

[mowton]

My educated guess is the MAF Fail will take priority and the PCM will default to the VE table despite the Dynamic Airflow disable, as that is all that is left to predict fueling.....and/or enter LIMP Mode

And thanks RWTD for the info

JMHO

Ed M

[HawkZ28]

Subscribing.

Also, a question of ignorance. With High RPM Re-enable, leave it alone, or set it to 0 as well?

[Cantalope Kid]

Subscribing.

Also, a question of ignorance. With High RPM Re-enable, leave it alone, or set it to 0 as well?

Leave it. Just set the "High RPM Disable" to zero.

[HawkZ28]

Sweet- that's what I did. Why is the reason- if I lowered it to 0 as well, would it still run a blend of the 2, or it will still run just MAF regardless due to setting disable to 0?

I've already 'seen' an increase in mileage (already at 130 where normally I'm at 100-120)- I'll of completed about 250 miles later today and will have the first comparison tank of results in for the 3.5 I5. Thank you for enlightening me!!!

[RWTD]

Subscribing.

Also, a question of ignorance. With High RPM Re-enable, leave it alone, or set it to 0 as well?

Are you running a Gen4 pcm?

Personally, I'd set High RPM Disable to say 1, or 50, or 100, and High RPM Re-enable to 0, but to each their own.

[HawkZ28]

Are you running a Gen4 pcm?

Personally, I'd set High RPM Disable to say 1, or 50, or 100, and High RPM Re-enable to 0, but to each their own.

Honestly I don't know- whatever was stock with my truck- I believe it's physically the same as the LS2's, but the programming/code is completely different for the I5/6(?) than all the other platforms.

How can I determine if it's gen 4, or the PCM code number?

I'll try those settings out in lieu of my current 0 and 4900.

On a side note, I picked up a solid 2mpg w/ my first tank of testing- 24.5mpg, and even though off idle it's a little bit lazier compared to before, she runs MUCH smoother and pulls harder under accel. That was the only thing I changed in my tune FWIW to any I5, or I6 guys that might read up on this. Wish our TB had a MAF!

[RWTD]

Yes, that would be a Gen4 system.

[scv8]

Does disabling the VE effect throttle response?

Thanks

[HawkZ28]

Does disabling the VE effect throttle response?

Thanks

Yes sir.

[RWTD]

If you tune the MAF in properly you won't have any throttle response issues.

[HawkZ28]

One more question- since I've switched to MAF only, I've noticed a large discrepancy between the values of MAF airflow and VE airflow, that wasn't there before. Before they were almost spot on. Has anyone else experienced this when switching to MAF only?

Should I ever decide to go back to blended or SD, if my thinking is correct, wouldn't it be wise to histo the difference and raise the values to match the MAF airflow in the VE table?

[Cantalope Kid]

A discrepency? Please explain further I don't follow... You shouldn't be concerned with VE if your running MAF only. If you want your VE to be spot on when you go back to Hybrid mode (MAF/VE enabled) then you need to tune the MAF in seperate from the VE.

[HawkZ28]

I'm still using the same scanner settings as before I switched to MAF only, so I noticed that in the scanner, say my MAF airflow is reading 2.684lb/min, whereas my VE airflow is reading 1.698, even though VE is disabled.

I just thought that was odd- my STFT weren't off that much- +/-5% when I started. I did STFT tune the MAF w/ VE disabled. Night and day difference in the truck. Can't wait to get a WB and tune in the next few months!

[Cantalope Kid]

To tune your MAF you need to be using the MAF!LTFT config. Its different from the one you use to tune your VE table in OLSD.

[HawkZ28]

I know- that's what I used.

[superchomper2003]

Hi, tried this on my buddies 04 silvorado with cam and worked great. Thanks! But 1 quick question, I have a 98 with the old style vortec and there is no high speed disable option, is there another way I can make it run maf only? thanks

[1genls2]

What is Germ-X? My car wont crank up now after I made some minor changes!! Swapped tunes again, still wont crank!!! Car Viruses?????