that is in OL.

correct me here.

i thought it uses the last value in VE table #1 at say 3200 rpms-90 or 100 MAP( my value = 51 or 59) for WOT.

and adds in the table for VE #2(my value = 42)

looks at the BLM i will guess for the last valid BLM at 3200 rpm(which i will assume are few to none)? OL 128.

modifies that fuel data (BLM) for rich-lean correction. OL 128 so none.

then looks at PE command for A/F desired and modifies inj pulse width accordingly.

my Q is how can i determine the appropriate values in fuel tables for main fuel table #2? i dont believe there is any feedback thru BLM other than that in table 1. do the net values of #1 and #2 need to be under 100. i assume so. in that case i have little room in tables to add fuel?

certainly i can use the WB and look at A/F for a prolonged higher RPM run at 3600-4000- etc and will do so.

reason i am questioning this is that i do not want to raise FP(17.5 now) if i can find more fuel by adding more fuel in table #2. seeing A/F on WB of about mid 13's.

7747. tunercat.

 

ttt

 

You can add fuel in either table as long as you don't exceed 100%. If you run out of room, your only options are to increase fuel pressure, or fudge the camanded PE AFR. This will work as long as you keep your PW's under control. It's a big balancing act. I have a hunch that you may need to go with more pressure.

 

my main fuel table #1 has a couple 98's in it around 2800 rpms/ 60-70 map or so. this was a result of datalogging BLM's. the high map 90-100 at over 3200 rpms i believe are over 100 (VE1 +VE2). tunercat allowed this. i will assume they will default to 100 during use. i noticed that early this week.

looks like FP will go up next week. and redo my main table 1 all over again.

 

Yeah VE is capped at 100%, VE1 is always added to VE2. I can send you a little spread sheet I use for quickly modifying your VE's based on BLM data. It also adds your two VE tables together and lets you see it as one big table along with a graph of your WOT VE curve. It helps to visualize whats going on.

Let me know what your e-mail is, the file is like 3k too big to post.

 

Thank You.

rfehn@amfam.com.

if my company blocks it i will givve you an alternative address.

 

Sent!

 

I resent the spreadsheet to your guys with some fixes that got the blm center feature working. Let me know if you guys use this thing.

 

Are you guys saying that if you're VE table is at 100 in a cell that is in PE, the PE doesn't add any more fuel?

 

the main fuel table 1 is added to MFT 2 and the sum total should not be in excess of 100. mine is over only in a couple spots so i am assuming the puter will make it 100. if over 100 i believe you need to up FP to allow under 100. that is what i may have to do. and possibly adjust my BPW constant for FP change.

the PE, when involked, ltooks at last cell car was in just prior and uses that value, however, does take into account the fact of the last BLM in that cell. i will assume to get enriched to commanded say 12.5/1 it multiples the fuel tables by some factor to allow the enrichment result of PE.

this is SD 7747. i am not up on MAF. yet...

 

I'm running SD 7730. I'm pretty sure I have more than enough FP and injector to fuel my car, I just need to lower the idle VE values/injector constant instead of trying to get PE to increase the fuel. Seems kinda pointless to even have PE if it can't help you increase fuel output of VE cells that are 100.

 

i think the 1 & 2 tables are just a scale to get the car to run A/F in closed loop at 14.7/1 / swing over it. the BLM function helps move the fuel when things change like cool temps(36F this am), wear tear/ baro pressure and the like. i am trying to keep FP as low as possible an my inj are having issues at low speeds idle in CL. right now i am rich at idle cruise but engine seems to like it OL. i forget why 2 tables instead of one. my PE is invoked at 50% TPS. may move to 33% to crutch AE. you need PE in a SD system. no way around it that i can see. other than VAFPR but that is a nightmare for me.

 

If your cam has a lot of overlap your O2 will read the oxygen that get's passed through the engine without combustion, that will make it think you are running lean, and richen the mixture. Might be why your car likes open loop.

 

i agree. also seems to calm down a happy IAC for reasons unknown. seems the fueling chases the IAC chases the spark and around and around. less surging for sure.

 

All for 8D purposes

That woud be true if that was how it worked.
But it's not-
The VE l/u routine is limited to a FF or 255 dec value.
That corrects to 100% decimal for VE table entry since a 255 entry would drive people nuts.
PE is added in to the F/A ratio which is limited to FFFF or 65535 decimal.
It's (PE F/A % chg vs CTS + PE F/A % chg vs RPM) x Stoich= Final F/A Ratio. Then FFA ratio X cyl density =BPW.
The VE is part of the cyl density calc.
Then the CLP corr and BLM are factored in.
PE is added once invoked and is based on rpm.
Doesn't care what the map is. Only PE state = true and rpm. Not sure how close that is for tbi.