Hello all. I think it's useful to have a separate thread for discussing matters related to The Great MAF Experiment. That's what this chat room is for

Link to the questionnaire

View the results/analysis here

Great idea @Zaid.

@Pᴀᴜʟsᴛᴇʀ2 can you see the results?

@Zaid - I can see the spreadsheet, if that's what you're getting at?

@Pᴀᴜʟsᴛᴇʀ2 yes. You recorded 0.9 lb/min for your Silverado, for which I the spreadsheet calculates 24.1% VE. If I change that to 0.8 lb/min VE drops to 21.4%

Yup.

Not a biggy, just wanted to highlight that

As for @Myself's entry, the numbers don't make any sense at all

I just wanted to confirm if there was a mix-up with the units or something

@Ben a few observations regarding your data:

1. GMC Terrain: I think this is a 3.6 L engine, not 5.3 L

2. Mazda CX-7: Please confirm this was a turbo GDI engine

3. Kia: No model or model year provided. I couldn't cross-check to see if the engine had a turbo or not. I find it hard to believe this has no turbo because it's pushing through the same air flow at idle as my M5 (2 L vs 5 L)

4. 2006 Sienna: The predicted VE is on the low side for this car. Do you remember what was the issue with this vehicle?

5. My estimates for VE are a bit on the low side for the 2006 Chevy Equinox, 2004 LeSabre and 2003 Ford Ranger. What can you tell me about these vehicles- what issues did they have?

@Zaid - I'm seeing it as a 3.0L engine

@Pᴀᴜʟsᴛᴇʀ2 in the spreadsheet or online?

online

I take it Ben had it originally as a 5.3?

The Acadia of the same year has a 3.6L engine, while the Terrain (the smaller SUV) has two engines: 2.4 4-cyl; 3.0 6-cyl.

@Pᴀᴜʟsᴛᴇʀ2 yes

@Pᴀᴜʟsᴛᴇʀ2 ok, I'll take note and update it tomorrow morning

1. 3.6 is correct

2) Correct Turbo GDI 3) Kia Sportage 2007 non-turbo (maybe because it's in kg/h instead of g/s?) 4) I suspect this one was a p0171 possibly (p0174 as well) deal LTFT were a little high and the b1 afr sensor was reading 3.26v.

5) Equinox, I think this one was my friends car that had a p0420 code and possibly a p0171 code LTFT were high ~17% at idle, we cleaned the MAF and the last time I looked at it LTFT were normal, but the p0420 code came back he took it back to the dealer and had the convertor warrantied. LeSabre, was a p0171 code as well IIRC it had a lower intake gasket leak.

The Ranger I'm unsure of, from the data I captured it looks like I was doing a VE test on the MAF I don't have my scanner with me to confirm the codes. At 4096 RPM the MAF peaked 73.36 g/s

sorry some of these were from early in the year and other than capturing some data I didn't take the best notes.

@Zaid I will repeat the measurement, it is just that in the next few days there will be no trips long enough for the engine to reach operating temperature

It is normal that the MAF values fluctuate wildly while idling?