Duts87ss

iTrader: (10)

I've been having trouble getting PE and AE situated for quite some time now. I *think* I understand the AE for the most part and can keep working on that on my own for a bit (it seems to be fairly close).

The PE has been giving me the most trouble as every time I tried to get happy with the pedal the AFR would go to 10.9-ish:1 and then the engine would spit and sputter. Today I decided (after the first three chips didn't do much) to lower both the PEvsTEMP (in my temp range set to 2.73) and PEvsRPM (multiplied the stock AUJN values by .5) tables way down just to see if I got a difference. Now at WOT, my AFR was stuck at 14.2, but if snap the throttle from a light cruise of about 30mph to about or just over half throttle, my AFR still reads 10.9 and then leans out the more throttle I give it.

The only thing that I can think of personally (came up with this idea after I decided I would make this post) is that my AE constants could be making it too sensitive to small throttle changes. Delta %TPS = 3.13 and DELTA LV8 = 18 (I'm going to change this to 56 per Orr's .bin).

Am I anywhere close to on base with my methods or ideology? Any recommendations to try or why I my have had to pull so much fuel from the PE tables; my injector constant matches my injector flow rate (supposedly) and I've adjusted the Injector PW vs Batt Voltage to get the MAF tables in range.

Orr89RocZ

iTrader: (20)

Whats your current AE curve look like? Also what does the PE enrichment vs RPM table look like?

Duts87ss

iTrader: (10)

PE vs RPM is just the the entire stock AUJN table multiplied times .5 .

3.12
3.12
7.81
3.12
7.03
8.59
7.81
11.72
16.40
13.28
10.15
8.59
7.03
9.37
9.37
9.37
9.37

Which AE table(s) would you like to see?

Orr89RocZ

iTrader: (20)

For PE mode, i always played with PE enrichment vs rpm like the one you posted.

PE mode enable should be set to around 50-60 LV8 or even higher so you dont get into it while light cruise or mild acceleration.

Also, %tps needs to be higher at lower rpms so you dont get into that mode.

AE table I used is AE vs change in LV8. Play with that. Low LV8 changes need less fuel so adjust those to see if it helps. If you are at light cruise and snap throttle to half and it goes rich and sputters, its too much of a pump shot, so the AE vs LV8 change table needs adjusted. Low throttle to half throttle is a decent amount of LV8 change. If you can log it in tunerpro rt or whatever you use and can see LV8 change, then you know exactly where to make the changes

My bin used 56 as minimum delta LV8 to enable acceleration enrichment. 18 seems way to low and probably dumping in alot of fuel when its not needed. MAF should take care of any mild acceleration points.

Duts87ss

iTrader: (10)

I've changed the Min LV8 for PE to 128 just to see how that affects the AFR at lower throttle openings as well as the change to the Min Delta LV8 for AE that I mentioned earlier.

I'll give it a try as soon as it gets above freezing.

Duts87ss

iTrader: (10)

Well, took it out to a local meet today and still getting the same problem at just over half throttle. I'll have to hook the laptop up tomorrow to see if anything looks funny in the datalog. I also need to add some timing in the meduim-light load areas around b/w 2500-3000 RPM; it stumbles in those areas unless very lightly accelerating.

My big concern is why it's going so rich at half throttle until just before WOT.

Duts87ss

iTrader: (10)

I didn't get a chance to get out and do a datalog today. Anyone have any other ideas that would make my AFR go so rich at just over half throttle to just under WOT? This would at least give me a few more things to look at.

Another question: In the "Acceleration Enrichment Factor vs Change in LV8" table, are the listed LV8 values the delta LV8 or actual LV8? Maybe I need to back off these some.

Orr89RocZ

iTrader: (20)

maybe the MAF tables in those areas need decreased to lean it out. May not be a PE/AE problem, especially if you changed the LV8 enable to the higher value

At what RPM/LV8 is this occurring? It may need PE vs RPM decreased in some of those lower rpm spots as well.

Duts87ss

iTrader: (10)

I've had the same thought pass through my head this weekend, but haven't taken the time to get a datalog; maybe before the weeks over though.

RPM/LV8 where it occurs I'm not exactly sure. Based on the factory tach, it occurs right around the stall speed of the converter (where the engine is obviously introduced to load) which is 2800rpm. I haven't done a recent datalog to verify the LV8.

Duts87ss

iTrader: (10)

Got a nice datalog this afternoon after work and, Orr, it looks like the upper MAF tables may have been the issue. When I rolled in the throttle, the BLM's would drop to 116 and pretty much hold there for a bit until PE took over. I'll have to get some more datalogs this weekend along with some more seat time.

Duts87ss

iTrader: (10)

Anyone see any issues with me raising the values for PE to enable so that I can tune the higher MAF tables without getting into PE mode?

Orr89RocZ

iTrader: (20)

I dont see the issue with that, infact i believe thats a good way to do it. Disable PE to calibrate the MAF to handle the fueling as much as its capable of doing, and use PE mode vs RPM enrichment to add fuel to the areas where the MAF is not capable of adding fuel, such as higher rpm WOT when the MAF reaches its limit of 255 g/s.
Your motor should see that by 5000 rpm i would think as my 383 saw that limit rather quickly by 4500-5000.
Also be prepared to take out fuel with PE mode vs RPM where there is TOO much fuel due to the MAF changes that you will make.

I didnt do my setup like this, i just left MAF tables stock except for table 1 and 2 for idle and light cruise. Table 3-4 seemed closed enough for heavy part throttle and then used PE mode vs rpm to tune WOT. Either way works fine

Duts87ss

iTrader: (10)

My intentions would not be to replace PE but to get BLMs in line so that I could then add or subtract the needed fuel in PE vs RPM.

Orr89RocZ

iTrader: (20)

yep you have it correct. That is what I'm saying to do. WOT you cant rely on BLMs since its goes open loop anyway. This is where you need a wideband o2.

Duts87ss

iTrader: (10)

This method seems to work so far (only logged once). It still goes rich and spits and sputters when I step into quickly; definitely need to back off on my AE.

I'll try to get another log this weekend.

Duts87ss

iTrader: (10)

Last weekend when I got my last data logs, TunerPRO locked on me (or lost its connection). I saved that log and restarted the computer and car then started logging again. Now that I'm trying to adjust the parameters based on last weekend's drive, I'm noticing that the numbers for the first log will show rich for certain MAF values while the second log will show lean for the same values.

Is there some test I can do to test the ECM? I'm beginning to suspect it as a culprit. I don't want to just throw away $100 and that not be the problem, though.

I went to the track yesterday and could only watch everyone else run. I'm getting very frustrated with it again.

Duts87ss

iTrader: (10)

New update:

I've been using the spreadsheet that I posted about in my MAF Voltage post and have gotten the MAF tables darn close (to the point where I need to make half the change the spreadsheet gives). Yesterday I decided to go out with some PE added back in to see what happens. It is now lean in PE and also needs some AE added also, but still pulls 8-10 degrees of timing when I step into it. While reading the EBL thread, I came across a post about someone's exhaust being close to the body/frame and causing knock counts. After parking the car, I started thinking of how close my pass header is to the frame (very close). The next plan of attack is to unplug the knock sensor and go for a drive progessivly getting more aggressive with the throttle and see what happens. This may lead to modifying the header, frame, motor mounts or some combo of the three.

Wish me luck.

bl85c

iTrader: (2)

Are you using AUJPWB to log afr? If so you may need a HUGE change to the PE table to get the afr you need. Mine's at 72%! I'm still trying to figure out what's causing this.

Duts87ss

iTrader: (10)

No, I'm using a modified AUJN (MAF setup). I was actually very rich at WOT (or any close to it) because my higher MAF tables were too high for my setup.

Orr89RocZ

iTrader: (20)

Glad to hear you have some progress going. Dial in the tables the best you can and work PE to get the fuel for WOT.

What kind of timing are you running for cruise and at WOT? Pulling that much is pretty bad, its either picking up something like false knock from exhaust like you mention or actually having some serious issues in the chamber.

You can modify how much timing is pulled from the knock sensor. There is a knock retard table and you can adjust how many degrees are pulled out. Just limit those values rather than unpluging the sensor

Duts87ss

iTrader: (10)

Yeah, I noticed that you had changed quite a bit in your bin dealing with the amount of retard and ESC attack rates. I left mine stock as a safety feature.

At the moment, I feel pretty confident that it's false knock because while being smooth with the throttle (while logging without PE) I covered much of the timing table with no significant knock. What I did encounter was less than 2* at light cruise (possibly false knock also). I can hear something rattling as I accelerate from a stop; I'm just not sure what it is yet.

Oh yeah, my timing table is a modified version of your table.

Orr89RocZ

iTrader: (20)

my table was probably far from perfect but it worked well. It seemed to be around 35 deg for majority of part throttle running which is fine, and i ran only 34 at WOT since it made max power there. I ran 26-28 at idle to help tame the cam but with better fuel control i probably could have ran less timing at idle. Doesnt really matter tho.

If its working for you thats fine but if its not, then maybe your combo wants something different. Give it what it likes that satisfies the ecm and see how it runs. Then increase timing to see if you gain anything. Track or dyno would be best to see the gains. If its picking up with timing, keep giving it some. THen you know the knock is false and can desensitize the sensor.

Part throttle timing is abit funky at times. My new 401 motor doesnt seem to like more than 32-33 degrees at lower rpms and loads but I've seen other tables where guys run 38-42 deg. Anymore than 33 it will pull 2-4 degrees. I was thinking it was false but cant be for sure without more tuning time on the dyno and such. Same heads as what was on the 383 just different cam and compression.