blakerose

iTrader: (1)

I bought an autoprom and am trying to tune a 7730 ecm for a 383.

-First problem-
I don't know what Mv is normal for my o2 sensor to read. It's not throwing a code but it goes from 200-800 and it looks wack. I put shorty headers on that i bought from a member here and the o2 sensor was custom welded in already.

-Second problem- If the o2 sensor is reading adequately then my car is running way rich. I know how to convert BLMs to the VE table values but it doesn't seem to update very often in these logs and it's mostly at 108-110 even though I have lowered the tables via emulation dramatically. Which is scary to me and leads me to believe my first problem is my only problem right now.

blakerose

iTrader: (1)

"Good oxygen sensors have even waves in the 150 mV to 850 mV range while ascending or descending within a 100 mS or less when the system is in closed loop." is what i found while searching for an answer so sorry. i got stuck in header related problems before i made this post.

RBob

iTrader: (1)

What you found is mostly correct. The cross-count every 100 mS is rather fast for a NB O2 sensor. At idle the cross-count can be much slower at 3/4 second to a second.

At speed it can be in the area of 4 - 5 cross-counts.

Note that is is only in closed loop. In open loop such as WOT a cross-count should never occur once the engine is up and running.

There are screen shots of this on this forum.

RBob.

blakerose

iTrader: (1)

Thanks for your response RBob

Had a loose injector and my initial timing wasnt quite at 6degrees and with minor ve and sa table changes the car seems pretty normal now

Started with stock VE tables and took away 2 value numbers in all cells until i got to mid 120 BLMs. Some rpms it will be in the mid 130s. my oxygen sensor is on shorty headers and basically reads 700plus the whole time however, I don't know what to think of that.

Timing is what i have spent most of my time reading about and the table throws me for a loop still. if i stomp on it then it drops to 13-16 degrees 3k-6k. that's just stupid as hell in my mind

here's a link to my current sa https://i.imgur.com/7kKpwNj.png

RBob

iTrader: (1)

What BIN did you start with?

RBob.

blakerose

iTrader: (1)

I started with a ANJF 5.7TPI 700r4. https://i.imgur.com/F6TzSYM.png
looks like some values are too low by my own doing. still the default higher map/rpm values look to be too small even for stock cars.

I played with the graph and came up with this. seems to make sense to me but my only hands on experience is with circle track carbd engines. and 1-2 weeks of tuning research
https://i.imgur.com/ASaBv8w.png

JP86SS

iTrader: (1)

The way your bin is setup, you must increase the P.E spark tables to get what you want for final SA. The table shown is for part throttle, The PE table adds to this.

The O2 sensor could be getting too hot (needing a spacer) or could cool off at idle (if its not a heated unit) You need to understand what it "should" be doing and verify your setup has it working correctly. Check out the stickys up above.
It may be fine as it is, hard to troubleshoot without all the running criteria stated.

blakerose

iTrader: (1)

o2 sensor is still on my to do list in terms of research and i will start looking into the power enrich sa right now

edit- another thing i have see is poeople turning pe functions off

blakerose

iTrader: (1)

What's a 12 initial, 36-38 max advance map look like?
I was told to use a vette 8D map for a 383 but during emulation my sa btdc goes almost to 50 so i immediately stopped that. the default 5.7 fbody bin is what i use but it goes into the 40s and knocks sometimes. the car surges on take offs, slow or hard, and feels weak.

i've tried adjusting them a little, my imgur link above, but we can probably agree that it looks horrible. I honestly thought it was ok at one time

RBob

iTrader: (1)

Are you changing the BIN's initial SA to match the distributor physical base setting?

RBob.

blakerose

iTrader: (1)

bin is set to 6, dizzy is set to 6

RBob

iTrader: (1)

Then unless you messed with the max & min SA it can't go to 50* BTDC. See this thread:

https://www.thirdgen.org/techbb2/sho...hreadid=317768

RBob.