Ken in AZ

OK - I just tried it from a different computer and can open the files

Ken in AZ

Also - I have a home-made intake....Janky setup but I thought it would work...

Thanks to Amazon Prime - tomorrow I'm switching to an S&B intake as it looks like it has the MAF set back from the filter which may give more consistent MAF readings

Plus I have another MAF in the garage to test against

Ken in AZ

The S&B intake delivers - I'm impressed. IATs temps are way down as to compared before. Out here in AZ with the AC on my IATs wouldn't be uncommon for them to hit 150-160deg hottest they got with the S&B was 118deg.

Also, the damn thing just drives better all the way around. Snappy down low, crisp throttle in most areas. I'm tempted to go put another round of VE and MAF tuning on it tonight just to see if that was my main problem.

Ken in AZ

A little update...I got my new L92 intake and it has a different style pcv and MAP sensor so I had to order new parts to match it. Bummer as I was looking to tune it this week.

And I think I found my main problem when tuning - I could never really get the fuel trims in line. I had my table setup with the error ratio in AFR not in lambda - since we have E10 out here all year long my stoich value was set at 14.13 but my SD tune is set to lambda 1.00 which my wideband would read 14.7 and that's what I had the value in the table referencing. So the error % I was using was to get the AFR to 14.7 which would constantly be off a few percent. I also couldn't figure out why I could never achieve 14.1 AFR after being tuned - But now I know I really was, it's just my wideband is only calibrated to display lambda 1.00 as 14.7 - I'm very interested in tuning with the correct values now to see if that helps. I still have a B1 and B2 STFT split which leads me to believe I have a vacuum leak on B2. Technically, B2 should be the rich bank according to the firing order.

Question - I have read that the PCM likes to run at Stoich 14.68 and people just adjust their PE to match their fuel type. What's a better method, to run 14.13 Stoich for E10 or run 14.68 Stoich and adjust PE to offset for fuel?

Thanks,

Ken

FFDP

iTrader: (2)

My state is also a up to E10 but more often than not it's only 3-7% at the most.

I always keep it at 14.68 and have no issues, to me it wasn't worth it to change it to 14.1-14.3 for just a minimal change in E content.

Ken in AZ

Ok - but question, wouldn't that technically cause you to run a little lean at part throttle non-PE situations? Does that mess with the driveability?

FFDP

iTrader: (2)

No because everything is still in closed loop, fuel trims and corrections are still being made. My trims are within 5% of zero all the time.

I am also able to set my stoich readings to 14.68 for 0-10% ethanol content to keep everything in line. The older GEN 3 computer just have a generic stoich number.


Also think about it, so many states run E10 fuel now and there are hundreds of thousands of GEN 3 trucks running out there with stock calibrations with 14.68 as the stoich value. I've never seen a problem with these vehicles. I kept my old 06 Sierra at 14.68 with the E10 fuels here, did VE and MAF tuning with no problems.


As long as it still running around 14.3-15 AFR while cruising with no whacky fuel trims it's just fine.

Ken in AZ

Makes sense - AFR and Stoich can get confusing - and yes I have the Gen 3 PCM and have crazy fuel trims on B2 (+14 in some situations) which I think is the cause of my driveability issues. I'm really hoping its the intake manifold that's leaking air causing the issues. What's weird is that the idle trims are right in line as to where they should be but as soon as I go part throttle that's when things get whacky.