logging with '7427 vs '7747

[EagleMark]

Mark you ALWAYS kill PE when you're datalogging for VE-adjustment correct? Seems like I remember reading somewhere that somebody cautioned against disabling PE b/c it would make you too lean, but if you want accurate BLM it seems you HAVE to temporarily disable PE. And besides does any harm come of this anyways???? It's not like you turn PE off and LEAVE IT OFF.

Right, when VE tables are correct, meaning BLM are in ballpark or Wideband is correct then I turn PE back on.

Wrong it will not make you to lean! It will stop you from going rich and skewing data.

PE = Power Enrichment. It is added to VE table, if VE table is not correct then neither is PE. PE adds fuel and spark to give more power when needed, it also changes AFR to lower then 14.7 to 1. If you turn it off then you can accelerate more and fill in more BLM numbers that are accurate in your history table, notice how you can't fill them all in anyway? Well if PE was on some of them would be wrong data... same theory for EGR, Air pump, Lean Cruise. Everything is an adjustment to the VE table.

7427 also has huge PE delay time so need to read up on that to actually get it to work when you hit the gas, not 60 seconds after... we talked about this and it seems some bins have no PE except after a minute which is probably there to cool down the cat at that point? Worthless PE...

[CDeeZ]

Okay, I'm glad that I know for certain what a hack is.

This is starting to really hone my understanding of PE! Excellent!

Thanks for tipping me off about the PE logic Mark. Do you have any suggestions where I might read to learn about dealing with PE in the '7427? I need to work on the VE some more before I worry about PE but most BLM cells are +/- 3 so VE is pretty close.

[EagleMark]

Plus or minus 3 and your really splitting hairs each day the weather changes...

The PE code zip written by 93V8S10 will explain the complexity of getting into PE, but don't let it confuse you, most of the problem is in the delay time.
http://www.gearhead-efi.com/Fuel-Inj...Information-OD

I think this is the thread that got him to working on that breakdown.
http://www.gearhead-efi.com/Fuel-Inj...PE-not-working

[CDeeZ]

I just read that thread, and also have been looking over the PE Code that 93V8S10 contributed. I'm going to make those changes to my XDF over the next day or two, and try messing around with the PE a little bit.

Someone needs to shake the hand of 93V8S10 and buy that man a beer. What a colossal amount of work to put that flowchart together and document the code at work!

Even though the PE has like 3000 parameters in this mask, it does seem pretty glaringly obvious that the problem is indeed the delay time!
No matter where you are on the flowchart, Basically every other PE setting is going to be a moot point as long as the delay timer is preventing PE.

[EagleMark]

IIRC that's all I had to do to get PE NOW, when I hit the gas... set the TPS% so it only comes on as needed, I usually go 50% TPS.

[CDeeZ]

Fifty percent? Does you r mileage suffer with PE coming on that low? I was going to lower the
TPS VS PE table to like sixty but now you got me wanting to try fifty percent. "The TPS for Fast PE" was the PE table with the values set way high like eighty or eighty five %

[EagleMark]

I don't normally hit 50% when driving so it has no effect on milage. If you've got a big truck and hit 50% while normal driving then by all means raise it.