BPC question. Can you check my math? 7060 $85

[chevmasta]

Sooooo,

After reading some more about TBI tuning my 7060 $85 PCM 454 93' K3500, I realized I haven't probably set it up exactly how I should. It runs good but still needs tweaking. So I'm starting over.

Can you check my BPC math please?
From davew's calculator I checked the BPC for the stock truck.......his calculator says 134. MY OEM BANC.bin has 142. thoughts? This is for 80lb injectors.

Only mods the truck has is a set of JBA headers and a 3" exhaust with a fuel pressure increase to 16lbs.

Using this formula: NewFlow = OldFlow * (SqRt(NewPsi / OldPsi))
I get 92lb injectors.

Plug that into davew's calculator spreadsheet and I get 119 BPC value.

So would you suggest one of the very first things I change in the .bin is put the BPC at this 119 value?

Thanks,
Ryan

[EagleMark]

BPC or in other masks BPW is 134 for 74lb injectors and 140 for 80lb injectors.

I get 92.38 and BPC of 120.41 so now we are splitting hairs, but yes 119 would be the first thing to do in bin file.

Before retuning off BLM/LTFT disconnect power to PCM to loose the BLM learn and let it relearn.

[chevmasta]

Thanks Eagle,

Can you give me a sanity check for initial parameters to change? Here's what I believe I should start out with:

Initial advance: 4* (set to match dist)
WOT delay: zero'd
Base Pulse Width Constant: 120 (calculated above)
Min Coolant temp to Enable EGR: set to max value
Fuel Cut Off Engine Speed: 4200 (max oil pressure it 35psi hot. I never go over 3600 or so in this truck anyway)
Fuel Resume Speed: 4100
Max spark Advance: 42*
EGR Flag: unchecked
ERR 32 Flag: Unchecked
Power Enrichment Spark Table: zero'd
EGR Spark Advance Correction Table: zero'd

Are there any other item's that you would recommend I start out changing first thing? Before I start tuning VE and Spark Advance tables?

I have the G3 selector with the EX switch so I can have 16 maps. I currently have a map for towing, and for high idle (runs my winch).

Help is appreciated,

Ryan

[EagleMark]

Looks sane.

Usually no reason to change MAX spark.

I have 2 EGR Flags, neither turns it off, both change how EGR works, so look at that one.

Smoothing the VE table makes it easier to start adjusting IMO...

http://www.gearhead-efi.com/Fuel-Inj...Information-85

HTH!

[chevmasta]

I think I misspoke. I went and looked at my BANC.bin and it had max spark at 41.84*. But the spark table has many 45* cells.

I'll just change those cells to match the maximum spark value.

Ryan

[EagleMark]

41.84 is where it's supposed to be. 45.00 in max decell minus the Intial spark advance 3.87 = 41.13

Normally you should leave all the decell spark advance alone, especailly when they are that high, you don't know what Decel, or DFCO spark adders or subtractors are going to do. This mask is not complete, but by the looks of those decel spark advance numbers I'd say there is none. From left to right about half the table and bottom to top about half the table as long as it does not interfere with your acceleration and cruise spark areas.

Hmmm... BANC is an Export bin! May be open loop? Lots of exports are OL leaded fuel. Did it come with the truck? Here in US?

[chevmasta]

Do you know if this PCM has a parameter to set the "target" or "desired" AFR for WA state 10% ethanol Fuel?
14.13 vs 14.7?

All I see is OPEN Loop parameters in the .xdf? I ASSUME this would be a closed loop parameter?

[chevmasta]

AWESOME!

Thanks for adding that EagleMark!

the .xdf I had been using was called $85sort.xdf
I'm not sure where I got it from (I think on here though) when we were going thru all that stuff about the two different masks.....???

Tomorrow is playtime! Gonna go tweak my VE table for awhile! :)

[chevmasta]

I was reviewing my last log see attached. Engine Runtime of 358 seconds. I was 100% throttle and the ASYNC Flag showed Yes. The ASYC BPW stayed at 0.00 while I was at WOT.
The ASYNC BPW shows a number virtually all other times than 100% throttle........when the ASYNC Flag isn't "yes". Take a look at the log.

This is a bin that the ASYNC is supposedly turned off.

My "BPW" is about 7.00ms during much of the WOT run in this 7.4l
I also had my "BPC" set to 140..........vs the BANC.bin of 142.