Working on a Timing Map for all!!!!

[RacerChris]

Well I figure I would try to help the whole and experiment around with some timing maps. What I am trying to acomplish is I want to figure out what timing is being used when engine bucking/sluggish behavior ocurs.
Here is the Scan Tool maps I have created.

Timing..... RPM vs MAP, RPM vs Commanded AFR, MAP vs Commanded AFR, RPM vs Actual AFR, and MAP vs Actual AFR, RPM vs Cyl/Air.

Spark Retard.... RPM vs Cyl/Air, Actual AFR vs Cyl/Air, MAP vs Cyl/Air,

I am hoping that by logging these perimeters I can gain a better view of what is actually going on when there is a hesitation from idle to part throttle and when there is bucking under light load conditions. I also hope to use it to adjust my timing in a particular area to a optimum setting.
Please let me know what you think and if there is any suggestions. I will be doing the first log in the morning when I go to work EARLY!!!! I will try to post some findings at lunch.
Wish me luck!

[SSpdDmon]

Pics of timing maps last used in my h/c car in post #8.

http://forum.efilive.com/showthread.php?t=4661

[WeathermanShawn]

You may find it is a combination of many factors. Timing, IAC parameters, and fueling. I have used a lot of the EFILive idle tutorial information with relative success.

I will be interested in your results. For me, the little bucking I have (~1600-1800rpms) always responds to fueling and IAC adjustments the most. When I am in DFCO, no bucking. Still convinced is all about reversion, and obviously timing is involved.

[RacerChris]

I have been meaning to update this post for a while but I have been pretty busy so sorry to any that have been waiting for it.
Well what I cam up with by logging those tables was I found my bucking and surging wasnt caused by timing at all. It was strictly fuel related. I played with timing up and down the cells it was happening in and played with the IAC but it had little to no effect. Frustrated as I was I decided to try throwing the stock calibration back in and start from scratch. What I got was no bucking/surging. I slowly started transfering my mods to the calibration back over and when I changed the fuel maps... There it was again. I was running my car lean as I could in the 55Kpa and below to save on gas as I drive it daily to work 30 miles one way. My bucking always ocured at idle or on decel when the converter was locked and I was pulling high vacum. So I richened up those specific cells and presto... The bucking/surging started to disapear! I ended up with a AFR of between 14.3-15.2:1 to eliminate it entirely. All my other cells I was able to keep lean so my fuel economy was affected little.
So my advice to all..... Try logging your VE table and note what cells the bucking occurs, and then add fuel to those cells. I run COS5 so it may be different on other platforms but the principle should stay the same.
I hope this helps out at least a few so please let me know if it did.

[joecar]

Are you running a SD(open loop) tune.

[RacerChris]

Are you running a SD(open loop) tune.

Yes, I run Open SD.

[WeathermanShawn]

I have also done tunes/logs and locked up timing parameters, and IAC manipulation on various runs. It always seemed to be an elusive recipe of fueling, timing, and IAC (airflow) combinations.

It is interesting because what little bit of annoying bucking (1600-1800rpms) I occasionally get, if I zeroed out TC airflow it certainly helped. Also while in DFCO..NO bucking. (I'm running traditional closed-loop). I know several have commented that bucking is is simply the engine attempting to 'rev' faster than the air and fuel requirements allow at that rev/low cylinder airflow.

It seems like if you can simply slow down the engine revs on deceleration, or get the fuel mixture to burn properly..whether through fueling, timing, and engine braking (IAC parameters), it makes it far less noticeable.

[RacerChris]

Thanks weatherman!
Unfortunately I have bad news! Tonight on my drive home the Camaro started missing when I was puling into the sub-division and then it quit all together. I tried starting it back up but then flames came out from under the hood. Long story short, the car is toast. It broke my heart seeing the firemen knocking out the windows and tearing the fiberglass hood off.
I will miss her!
Luckily its fully insured with aftermarket parts coverage so I shouldnt have too big of a loss. I dont think I will be getting another anytime soon but instead I will be turning my full attention to my 97 Z71 that I am transplanting a 06 LBZ Duramax into!
I probably wont be on here much but to answer a few questions that people have untill I get that going so I will miss you all but I will be checking in from time to time.
Thanks to all that have helped me with my issues.

[joecar]

That's like losing a family member...



What happened, did the fuel line break...?

[RacerChris]

Yes it is joecar. and yes I do believe the fuel line broke... Right where it connects to the plastic line by the intake. That’s at least were the most sever burning occurred.
The really sad part to me is I am unsure if I will ever own another... I am strapped down now with a little girl, a mortgage, and various other bills. I was planning on selling her in the spring anyway to pay to finish the truck, but now that she is gone it truly brings a tear to my eye. 2 Years of blood, sweat, time, smiles, and frustrations..... Gone in 7 minutes. Maybe it wouldn’t have been so bad if I had sold her knowing that it was going to someone with the same passion, then again maybe not.
I think once I am done with my truck this coming summer though I will start looking for my dream..... 1970 1/2 Z28 w/the RS split bumper! I always wanted to get one and go old school with a big block and a big 8-71 with dual carbs on top. I found a chassis and body recently in somewhat poor shape for $1900.00. But now that I think about it... I will really miss the EFI. I will really miss tweaking the VE, fuel and spark tables too! Hell.... Maybe by then GM will fix that damn rear bumper on the new Camaro and offer a Z28, If they do..... I think I will be back to EFI!!!
Well I am going to try and get some sleep. I have been up half the night sick over this.
By the way.... I will be probably retaining the vehicle and parting it out. If I do I will have a few goodies to sell so I will update as soon as I can.
Thank you for you condolences.