turbo Silverado lean spikes/stumble

[joecar]

lol, I'm officially an alien.

[BLK02WS6]

Joe - what would make my laptop keep going to "not responding" while trying to log? It freezes up and I have to restart it. He brought the truck over and I tried to use my laptop to log - never had this problem before... any ideas?

[joecar]

What laptop is it...?

What V7 software build version...?

Is this with FlashScan V2...?

[BLK02WS6]

Toshiba Satelite/1.40GHz/4GB RAM/Windows 10

V7.5.7 (build 299)

Yes, FlashScan V2

[BLK02WS6]

So, with a scaled tune, we got a good pull on it with no MAF, and the spikes aren't there. It was a bit rich, but pulled great even through a shift.

We hooked up the MAF, and the spikes came back - missing and stumbling like before we scaled the tune. What gives? Can we not run the MAF with this much boost?

[joecar]

I think it has to do with C0803, C0804, they have a maximum range of upto 512 g/s... but you scaled, so I don't know...

[BLK02WS6]

I would think if it was to do with those, it would do it in SD, but it doesn't. I'm searching through other posts, but I'm not finding anything so far. I'm stumped. We may just have to run SD and he can plug in the signal wire when he has to go to emissions (and stay out of the boost)... I'll keep trying to figure it out, but this is getting extremely frustrating...

[BLK02WS6]

One other thing I forgot to mention - I kept knocking down the VE table in huge amounts trying to lean it out to commanded, so I got to thinking... the PWM fuel pump maintains pressure much like a regulated setup, but the IFR table is sloped. I changed it to a flat table and the top end of the VE came in much closer. It seems to be working. If only I could figure out this MAF issue... Here is the latest tune and log with no MAF.

[joecar]

One other thing I forgot to mention - I kept knocking down the VE table in huge amounts trying to lean it out to commanded, so I got to thinking... the PWM fuel pump maintains pressure much like a regulated setup, but the IFR table is sloped. I changed it to a flat table and the top end of the VE came in much closer. It seems to be working. If only I could figure out this MAF issue... Here is the latest tune and log with no MAF.

Ok, so is that how the PWM fuel pump behaves, it increases rail pressure as MAP increases... if so then a flat IFR makes sense.

[Mean Green Z28]

Ok, so is that how the PWM fuel pump behaves, it increases rail pressure as MAP increases... if so then a flat IFR makes sense.

Yeah the tables have low/normal/high(PE) kpa settings and it's been good at keeping up with the set pressures so far! Still stock pump but injectors don't seem to be maxing out yet and if anything, the wideband readings show rich!

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