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Last edited by LRT; 05-24-2021 at 11:32 PM.
Flashed the cal only after cloning back to my own BIN. But something is still weird. No MIL, but the idle AFR was in the high 11s low 12s; Part throttle was low 14s and WOT was 16-17 before I let off...didn't give it a full pull.
I wish I had better data, but the bluetooth logging is being problematic.
EDIT: Took another drive to record a log and found there is actually PE or something going on. There's a 1sec delay or so, but after the initial 17:1 lean spike, it drops to 13.5ish at WOT.
Last edited by woody80z28; 03-29-2020 at 10:02 PM.
80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
https://www.youtube.com/c/GEARHEADdezign
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Last edited by LRT; 05-24-2021 at 11:32 PM.
I have the wideband output tied into the PCM for logging, but can't get it to work right. The numbers I'm referencing come from peeks at the gauge while driving.
And the gauge had another face for lambda, so I'm pretty sure it will read 14.7 as stoich, even with the E10 crap we have at there pump.
80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
https://www.youtube.com/c/GEARHEADdezign
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Last edited by LRT; 05-24-2021 at 11:33 PM.
Yup, peeking at the actual gauge is how I'm getting numbers.
I'll see if I can change the digital readout to lambda. I don't recall that in the instructions. The gauge face has 1lambda at the same spot on the outer led sweep as 14.7afr.
I've tuned my Beretta as "14.7 stoich" according to the wideband even though it also runs E10...and the actual afr is probably in the low 14s. I don't think the wideband knows or cares.
80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
https://www.youtube.com/c/GEARHEADdezign
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Last edited by LRT; 05-24-2021 at 11:33 PM.
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Last edited by LRT; 05-24-2021 at 11:33 PM.
Hmmm. Similar results, even with a different calibration on the MAF. WOT spikes lean and then comes down to mid 13s. Low 12:1 idle initially, but corrects itself to 14.7 with STFT pulling a ton of fuel out.
I'm new to the MAF and its effect on fueling. All my OBD1 stuff has been speed density. Thinking about disabling it again to do some VE table refinement and reduce variables. As I recall, it ran a fair amount better that way, too. The STFT and LTFT are reporting correctly in the log, so I'm thinking that may be where my time is best spent in the immediate future.
Thoughts?
80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
https://www.youtube.com/c/GEARHEADdezign
I'd like to point this above right on post out. The MAF meter is probably almost 20 years old. 90% of the new/rebuilt ones are sometimes worse than the dirty/coated one you take off. There is no reason EVER to have to alter the transfer function of that MAF in the calibration. Are we smarter than GM on this transfer function? That type enclosed MAF with screens is dead nuts and reliable till it gets dirty or typical age ozone and dust coated. The only ones you can buy that seem to be correct are the AC-Delco and Delphi NEW maf's, not the rebuilt junk at NAPA, Oreilly's, Autozone, etc. You said you have a stock engine so unless you made changes to alter the VE(exhaust, cam, porting, etc), your VE table should be pretty right on too. Best thing to do to start is turn off VE and get it to run correctly on just the stock MAF settings.
I am not talking about cartridge MAF's and how they are critical to inlet ducting and any change in that can cause a lot of grief.
LRT has been very kind to help you, chasing failing or just bad equipment doesn't help anyone.
Good luck,
-Carl
-Carl
If that is true...
Why does GM have different MAF transfer tables for the very same MAF in different applications? The LT1s are different F-car vs Corvette LT1 vs Corvette LT4. The Vortec trucks are different than the Vortec vans. The 350 vans have 2 different MAF tables depending on which airbox they used too. The 4.8/5.3/6.0L trucks are different than a LS6 Corvette too. I think GM calibrates the MAF transfer for the airbox they used with the MAF. For example, ALL 2002 V8 gas powered vans had the same MAF and airbox. The 305, 350 and 8.1 all used the same MAF transfer except around idle.
I know my Express van ran like crap on a 2002 Express van MAF table using the 97 airbox and ducting. When I swapped to the later ducting and airbox it was still off. I had a good clean OEM MAF and a new smaller body Delco MAF that they sell to replace the larger LT1/Vortec MAF. Same results with both. Camshaft seems to really effect fueling up to about 30-50 gms/sec. First thing I do is disable the MAF and tune the VE. Then I disable the VE and tune the MAF. Even on stock setups they are usually pretty far off the mark.
Last edited by Fast355; 04-02-2020 at 06:44 AM.
I have some MAF cleaner, I'll give it a good cleaning.
I would have thought the tube style MAF would be accurate regardless of intake configuration, but I read otherwise. Like I said, I'm new to MAF stuff. If you're certain that doesn't matter...I'll believe you.
Mods consist of an intake tube and a muffler, so I would agree the VE should be pretty close. The fuel trims change quite a bit now, but maybe that's all influence from MAF.
80 Camaro Z28 - 550hp AFR 383 / T56 6spd (Holley HP EFI)
91 Beretta "SS" - 260hp 3400 MPFI / HM282 5spd (7730/$A1) sold! for crazy money...but I miss it
94 Silverado Z71 - 300hp Vortec 357 TBI / NV4500 5spd (7427/$0D) gone but not forgotten
96 Beretta "T56" - 4.8 LS RWD swap / 6spd (0411/2156)
01 Silverado 2500HD - stock Vortec 8.1 / ZF6 6spd (0411/8322)
https://www.youtube.com/c/GEARHEADdezign
In my experience the intake tube will throw the calibration out substantially on the MAF. I have a go to LS truck MAF calibration for the 07+ Airaid MIT that I like to use with earlier E-Fan conversions. I used my sisters low mileage bone stock 03 5.3 Tahoe with the MIT and E-fans as the only mods to create the MAF table years ago. Only reason it was even moded was the mechanical fan exploded and destroyed the shroud and intake tube.
I will say the MAFs on GM are far less picky than the cartridge MAF on Nissan and Infiniti. Even if you leave the OEM MAF in the OEM housing. Only change the intake hoses for freer flowing silicone hoses and the car will run rich. Luckily I combined the intake hoses with headers, high flow exhaust and a custom 2.5" dual exhaust that have an effect of leaning the car out.
Last edited by Fast355; 04-02-2020 at 07:02 AM.
I am not talking about the garbage 3 wire maf in the early stuff or the 3 wire used in the 0411 express.
-Carl
The 07+ 5 wire is not the same animal either. Continue on, I'll be quiet.
-Carl
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