DM91RS

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xjcamaro89

The temp here in PA when i ran on Wednesday was high 30's. ANd I do have a open element. I know i had high BLMs but i know the car is running rich or lean (which is rich and which is lean? above 128 or below 128) I plugged the info back into the XJ2 bin file and im attaching it, please guys take a look at it and see if it looks good for the Log and BLM log that i posted recently, i tried to smooth everything out a little, just want to know if it looks right and if I should go ahead and burn a chip with it and try it out, its going to be nice thursday with temps in the 50's so im going to log another long run tommorow evening (thursday), i want to get this stuff figured out, ive been spending a lot of time with this and the misses is getting upset, please, any input and help would be greatly appreciated, thanks again

xjcamaro89

I just read on another post that the holley 670 tbi is rated a 56# at 11 psi, thats what my car is running 11 psi, shoudl we change that in the bin file, or just leave it for now?

So if this is correct, using the equation you gave me at the beggining of the thread, the BPC should be 148.53? Right?

BMmonteSS

I was kinda afraid of that, that's why I asked but took your word for it. This would explain why your lean all over. I would go ahead and change the BPC but keep in mind that you'll have to completley retune your VE curves now which isn't a bad Idea since your getting into the 90% range in some cells.

It's an interative process. Once you get the hang of it you can retune your whole VE curve in an evening.

96LT4c4

I noticed on my Truck that I don't have a place to enter the BPC. All I have is Injector Flow Rate (per bank) and cylinder volume per cylinder. Is my BPC automatically calculated by the ECM.

BJYB
$0D

xjcamaro89

Do i just change my BPC, or do I have to change my SQRT also, or is that just something else i dont need to do, its just to figure another number out?


OK i plugged 149 in for my BPW (its the same as BPC isnt it?) and i will try another good run logged tonight and start messing with the VE curves and i guess start back over, thanks for clearing some stuff up guys!

BMmonteSS

XJ, it seems your BLM’s are maxed out at 150, this is what your max BLM is set to in your constants. This means the ECM can no longer compensate. So this pretty much confirms that you need to redo your BPC (or BPW) and start over. It looks like you did the math correctly, so just plug in that new BPC and do another log, an hour and half is bit long but a good way to get a comprehensive log. Keep your chin up and keep poking at it, once you get things in the ball park it will all start falling into place. You don’t have to change each individual cell like we’ve been doing. If you see that you’re universally lean or rich then just make a flat 4% change and log it again until you see BLM’s above and below 128 then you’ll need to adjust each cell individually or plug the tables into the VE spreadsheet. Like I mentioned earlier don’t spend too much time, plus or minus 5 BLM will do for now. When we start messing with timing your VE curves will need more attention. The reason we’re not messing with timing now is that we need the fuel to be in the ball park so we don’t run into the dangerous situation of lean and too much timing.


96LT, once again your ECM has room for more code so you have seperate injector size and cylinder size constants, so you simply plug in your injector size. Keep in mind that if you change the fuel pressure that the actuall size of the injector will change and the formula I posted for calculating this still applies.

Ronny

iTrader: (1)

point of interest. his leanest blms are right at tip in. with coming off a stop in first gear the rpm/map you end up in is lean in your log. worst case scenario. i have a manual trans too and i fattened up those lower rpm high map areas as i was of opinion there is no learning in those cells.

a couple yrears ago i did disable PE in order to see learning at higher rpm and higher map. as expected i found out i was in the 140 range on BLM. running 3200-3600-4000 rpms in 2nd gear on xway until you get some hits is one way to get yourself noticed . having hooker aerochambers on real duals it makes a bit of noise.

xjcamaro89

Ok, i changed my BPC and it ran good, i did about a 1/2 hour run pulled over and made changes using the excel spreadsheet, then did another 1/2 hour run and pulled over and made changes, then did another 1/2 hour run and made changes, i havent run the latest changes yet but im going to post them and let you guys see what ive worked on last night, and see if im getting closer. I figured out why my car took a dump the other night when i would pull out onto the road. That night i reverted back to another bin and made some changes, but bmmonte set the speed limit to 10mph to see if i was going to actually look at the bin file he sent me, well i reverted back to that file when i burned a chip that night and never changed the speed limit. So anyway i found that out last night when it did the same thing and i decided to take a look and sure enought the speed limit was set to 10 mph, so thats all fixed and taken care of.

BMmonte could you give me some instruction on trying to get the idle correct, because if i run one or more times this weekend to finish off my VE tables, i want to work on the idle and throttle response, and i know its will be hard for you to get to the boards this weekend and i just want something to work on, and there are some car shows coming up that I go to and i want my car to run right, im not really worried alot about tuning it up for high performance this second, i just need to it to run the way its supposed to , thanks!

DrivinVA305

iTrader: (1)

I just thought about this but if you run a cooler thermostat, say around 160-170, would you have to modify when the closed loop kicks in? Would there be anything else to change as well? I don't know if this fits into what is going on right now, but I thought I would ask anyways.

91RockS

XJ, increasing your BPW to 149 made a big improvement in your log. Most of your BLM's are now much closer to 128, but still a bit high (lean). Bumping the BPW up just a little more would richen the entire map up, but it's probably best to leave BPW alone now and go back and re-tune the VE tables. Just keep an eye on total VE (use BM's spreadsheet) and make sure you're staying under 100%. One or two more iterations using your datalogs and the VE spreadsheet and you should have all BLM's very close (+/-3) of 128.

DrivinVA305 brought up a good question. Several of the prom tables are based on "low coolant" and "high coolant". If you swap out the thermostat for a lower temp stat, are there constants that need to be changed so the ecm knows the target operating temp of the engine has been reduced?

BMmonteSS

Great news XJ, your VE curves look to be close enough for now. Lets get this idle figured out. What IAC counts are you at when idleing and what rpm" What about the idle do you not like? Is it mostly the off idle transition that gives you fits? If so have you tried adding some more pump shot since you corrected your VE curves?

If I sound incoherent it's becuase I was up till 4:30 this morning, and then got back up at 6:30 to get the studio ready for my wife. Consider mission accomplished, she has 12 models out there right now and everything works. Now someone explain to me why I'm in here talking about tuning when there are 12 profesional models within 20 feet of where I'm sitting???????

DM91RS

I guess 2 hours sleep "might?" make all but the horniest of us a little "sluggish"


Anyway..........you're still a newlywed right?

mjwadams

I am looking at upgrading my 305 TBI setup, and came across a site that sells TBI spacers:

GM Tbi Performance Parts + Accessories List

Has anyone used these in their Camaros?

RBob

iTrader: (1)

A BPC of 149 is actually too high. The injectors will be static at 3,600 RPM (based on 100% VE, 80C coolant, BLM of 128, and an AFR of 12.8).

I would adjust the fuel pressure up to the point where the injectors will flow enough fuel for the HP of the engine. It is a 350 which stock GM uses 61 to 68 #/hr injectors.

Once the fuel pressure is adjusted set the BPC to the proper value and continue tuning. A side note is that increased injector flow will show up as an increase in AE. So if it starts to chug a little on opening throttle will need to lower the AE.

RBob.

xjcamaro89

OK, i ran a few more passes and changed my VE tables last night (Friday) and i got it really good, +/- 1 or 2. So that is taken care of. AS far as the idle, after i made changes last night I let it cool over night and started it from a dead cold. it idled really good, all the way up through the temp range, so i think that is pretty much squared away right now, unless something else come up with it. Can you tell the IAC counts from the datalog? Or do i have to actually look at it while running? Let me know, but i still have the off idle problem, with a slight throttle response delay, could you post a couple of screen shots of where in the table to adjust for that problem and how far to go with the adjustment, thanks once I get this stuff all taken care of then we can move on to bigger and better things. Also i did notice today when i drove it, that it i take off and run fast up through the gears i just dont seem to have the power fast in the higher RPMs, i still have power but it doesnt seem like the power is there compared to slowly running up the RPMs in the gears. All that aside I am very pleased with what I , and we have accomplished so far doing this. And i filled up my tank today and figured my MPG from the last tank. I got 17 MPG with this thing! Thanks!

DM91RS

I wonder if this has something to do with your problem

BMmonteSS

Rbob and DM91 are on to something, time to dig up my old post. I'll see if I can get to it tonight, if not in the morning.

P.S. Photoshoot went great, wife is very happy....which means I'm happy.

GJSZ51

Not meaning to hi jack this thread, just wanting to give kudos, what a great idea this is...! The Q & A s are helping to re enforce the thought processes involved in tuning

xjcamaro89

I dont see how having the fuel settings lower would do anything major. im running 10psi fuel. we have to calculate the BPC for what the fuel is running, but even if this is the problem, can i adjust the fuel pressure on the Holley TBI units? i thought they were made so they could be adjustable? But i dont see an adjustment anywhere. Also the fuel pressure im running is right around the fuel pressure setting that the directions that came with the Holley TBI said it should be at, so where is the problem? Is holley wrong?

Fast355

iTrader: (2)

It makes all the difference in the world. Higher BPW, means longer pulsewidth/ more duty cycle and less RPM.

xjcamaro89

But I have the fuel setting PSI set where holley's instructions said it should be for the stock engines. Does anyone know the lbs/hr for 10.5 PSI of fuel? Or does anyone know what the BPC should be for a holley 670 cfm holley TBI? im running 10 psi fuel. I know someone out there knows what it should be?

Here is the thread I got the lbs/hr and psi ratings from:
https://www.thirdgen.org/forums/tbi/...ley-670-a.html

# 9 post
"I have one on a stock 350 truck crate motor with afterburn headers, 3" crossover, cat and cat back exhaust system with a Hyfire IV ignition. It runs rich at less than 2800 rpm and lean above 3200 rpm, even after half a dozen chips. So I called Holley, the information they gave me was 56# at 11 psi, 65# at 16 psi and 80# at 21 psi. I'm going to up my psi, but I want to install a shrader valve in the fuel line near the TBI. Has someone done this and can they post their method?"

And I have mine set at 10-11 psi and 56#/hr and that is what the chip is programmed for right now.

RBob

iTrader: (1)

It isn't so much that the BPC is incorrect, the real issue is that 56#/hr of fuel is not enough for the 350. The stock 305 injectors flow 55#/hr, so the 10.5 psi is OK for a stock 305.

I keyed on the BPC because that is what hit me. When I read that it was set to 149 I knew the injectors are too small. Do you know the HP rating of this engine? If so then an approprate injector flow can be calculated.

Going by a SWAG I would bump the fuel pressure to 18 psi and re-calc the BPC. That will be about 73 #/hr that is good to about 250 HP at 85% DC. If you have the stock TBI fuel pump I would recommand an upgrade.

RBob.

BMmonteSS

I just realized that we’re dealing with a full exhaust and TB 350, which you already mentioned….shame on me for not searching first. So it’s not too surprising that your injectors are too small like Rbob said. Holley TB’s are adjustable, there should be a screw right on top of the FP regulator, it would be on the bottom of GM TB’s since their regulators are flipped.

Ok so we’ve hit our first stumbling block in this tune, we’ve got our BLM values in line, but our VE tables are in the high 90% range so we’re running out of room. Keep in mind that the amount of fuel that is injected into the engine is calculated from our BPC, VE, WOT AFR and another half a dozen other modifiers. After all these calculations are done the ECM comes up with how long to hold the injector open. This is called your PW (pulse width)….makes sense. Now you have to think of how much time the injector physically has to open and close. Rbob explains it best in THIS thread, here is a quote that summarizes how to calculate how much PW is available at any particular RPM

Quote//:
Static is at 100% or greater. The '747/'8063/'8746 ECMs fire an injector every time a plug fires. There are two injectors. They alternate on plugs firings.

Before I go too much further this is in synchronous mode. Sync mode is sync'd to plug firings. This is the most common mode. I have seen a few cals that are always in async mode, but never an f-body cal.

So for each revolution (V8) there are four plug firings. It takes two revolutions to fire all eight cylinders/plugs. Alternating injectors, that means each injector fires twice on each engine revolution.

At 4,000 RPM (revolutions per minute), divide by 60 for revolutions per second: 4000 / 60 = 66.67 revolutions per second. Invert this value for the time of each revolution (or frequency thereof): 1 / 66.67 = 0.015 seconds. Or, 15 milli-seconds (msec) per revolution.

With each injector firing twice each revolution we need to divide the amount of time in half: 15 msec / 2 = 7.5 msec.

This 7.5 msec is the amount of time an injector has before it is fired again (at 4,000 RPM). The higher the engine speed, the less time there is for an injector to deliver the required amount of fuel.

This is why it is important to keep an eye on the injector PW. Once the PW value exceeds that given amount of time, no more fuel can be added. The darn injector is on ALL of the time.

At this point the only thing that can be done is to increase the delivery of fuel. Bigger injectors and/or higher fuel pressure is required.

As another data point at 6,000 RPM a TBI injector is static once it hits 5.0 msec of on time. For best results TBI injectors shouldn't be open for more then 85% duty cycle. At 6K RPM this is 4.25 msec's.

RBob.

Quote//:

Now that we know how much time is available to inject fuel we need to find out how long we’re asking the ECM to hold open the injectors. The easiest and most accurate way to do this is to just log it !!! So we go back to THIS thread and take a look where Rbob tells us how to get our PW to be broadcasted in the prom ID field. In summary we have to manually go into the bin file and change some things. This is more moderate level changes that won’t make any sense, but it will work. When I say manually I mean MANUALLY. We’ll go into tunerpro and open the tools drop down menu and click on advanced, then hex editor. What your are going to see looks like something out of the Matrix…take a deep breath and don’t get scared, it’s not that bad. What you are seeing is the actual programming that is on the chip, this is what our .xdf file converts into something readable for us to understand. The grandfathers of tuning used to look at this stuff and look for trends to identify timing and fuel tables and then manually edit these values…..be very glad we are where we are today. If you look you’ll see that there are addresses listed to the left and values listed across the page. We’re going to go to the following addresses and change the values to following values. For the address just look at the number D414 = 414, but in the hex editor your going to go to line 410 and then go over 4 places, if you look at the bottom of the screen you’ll see exactly what address your highlighting. I’ve attached screen shots of before and after edited parts.

Change to these values
Addr: Value:
$D414 $00
$D415 $AA
$D416 $00
$D417 $AB

What we have done is told the ECM to look up another value other than the PROM ID and put it in the ALDL stream in its position. The thread listed above also tells how to put your total timing into the ALDL stream, very handy. Now our Prom ID field in winaldl will give us a raw hex value for our PW, we then have to take whatever value is displayed and multiply it by .01526 and add in the injector bias value which can be found under the constants menu. This is where putting your log file in excel comes in handy. You can set it up to do the simple math for you. Ok so now we can do a log and see what our PW is getting up to. To get your PW as a % just divide the time available by the time used. The generally accepted limit is 80-85%. Since Rbob already did the math we know we’re going static. It will be a good learning experience to go head and log what static injectors look like. You’ll see the O2 peg rich/lean and feel the loss in power at whatever point the injectors go static.

So how do we fix this????? It’s pretty simple, we ran out of fuel, since our part throttle fueling is in the ball park and we’re still maxed out the only option is to increase fuel pressure or get larger injectors. So this means that holley is lying through their teeth about the injector size, or your motor has more done to it than just a big TB. (which it does) The procedure is to jack the fuel pressure up and then adjust your BPC until your BLM’s drop back into line. You can also lower your VE numbers as well, since both are used to calculate the actual PW. I would drop your VE 10% across the board to give yourself some more room then adjust your BPC from there. I know we’re not giving the ECM proper numbers now, but we have a big unknown in the system and it’s the injectors. As long as we’re getting the proper amount of fuel it won’t matter. It’s always better not to lie to the ECM, but in this case we have to since we’ve been lied to.

I hope I didn’t loose anyone there, please ask for verification if you don’t understand. Let’s keep it to PM’s and I’ll post up any clarifications I think are necessary. I’m not the best communicator, so please let me know if I’m not making sense.

BMmonteSS

Here is XJ's last bin with the PW mod done to it just like I did to the stock ANLU.bin file above. Let me know if anyone has problems with these files, it appears XJ's corrupted TBIchips bin file was just a fluke.

XJ from now on whenever you burn a new chip just change the # in the bin name so we can keep track of the progression of your tune, it won't matter if I make th changes or you do, as long as you always increase the number. In the end I'll post the complete progression of your tune.

O yeah, I also remembered how to post screen shots. My old fueling thread jogged my memory. Just do the cntl-printscreen then open up paint and past it in there, then you can save it as a .jpg

BMmonteSS

And to break every posting rule in 5 minutes I'll tripple post with more than 3 pictures in a thread.

XJ,
If your just wanting to get the car running better temporarily to get to a car show check out these tables and increase the 2 smaller tables by 10% or 15% and see how that helps out your off idle stumble.

xjcamaro89

I dont think my holley TBI has an adjustable screw on it. I know where you are talking about on the TB and there is a just a cap on it like the stock ones have. Would a Jet adjustable FPR fit on the holley TB? Or should I make it adjustable, also does a stock one fit on the holley because i have a spare that i can make adjustable, thanks again.

So BMmonte, you want me to run a logged run with the new .bin file and that will show up the PW on the log, so we can look at that. Then you want me to crank up my fuel pressure? To about 18PSI liek Rbob said and recalculate my BPC and retune my VE tables again? Ok would this sort of problem that we have run into be the cause of my sluggish throttle response off idle?

Thanks for all your help again guys. And the Holley TBI is for a 350 and it says to run it at 10-11 PSI, so maybe holley is lying again there? I dont know, but thanks guys!

xjcamaro89

How come TunerPro wont let me change those two AE tables you told me to change, i increase them both and save them, but if i open then back up the values are changed? Anyone else experience that problem?

DM91RS

[quote=xjcamaro89]I dont think my holley TBI has an adjustable screw on it. I know where you are talking about on the TB and there is a just a cap on it like the stock ones have. [ quote]

There is a cap covering the fuel pressure adjustment screw that you have to dig out before you are able to adjust the pressure. From memory they all come that way.

BronYrAur

iTrader: (1)

Because you're not changing the values enough for it to make the change. The least amount you can change it I believe is somewhere in the 50usec range. If you don't add at least 50 to the number in the table it will round back down to the initial value. When BM said to add 10% he didn't mean add a value of 10, multiply the current value by 1.1 to get your new value with 10% added.

xjcamaro89

Thats what I did, i multiplied it by 1.1 but what you said makes sense, because some times when i would change it some would change and other times it wouldnt, or it would lower my entered value a little, so would it be safe to say that i could increase each value by 50 then and then try it?

So what u r saying is that I need to drill the plug out on the FPR on my holley and there will be an adjustment screw, just want to make sure before I go ahead and drill it.

Ronny

iTrader: (1)

7747. tunercat.. my AE values can only be changed in a multiple of 61. 0-61-122-183-244 etc. i had some issues as you until i was told the above.

BMmonteSS

XJ,

You've got the right idea of what it's going to take to retune for the higher FP. Just remove the cap in the regulater and you'll see the screw. I doubt you'll be able to get 18 psi from the stock spring, just crank it as far as it will go without bottoming out the spring. (you'll see the FP go sky high when you bottom out)

Don't be afraid to make big changes to the pump shot tables. Go ahead and add 500 to the whole table. It's much more drivable with a rich pump shot than a lean one. Also getting your FP up will help make sure your not running out of injector during AE.

To everyone else, thanks for jumping in and helping out that is exactly how I want the thread to progress. If some of you more experienced tuners want to add to the discussion or write up a section on a particular aspect of tuning go right ahead.

Ronny

iTrader: (1)

topdownsolutions.com sells a spring($10) one step stronger that the stock GM spring. not sure if Holley is any different than GM on strenght

xjcamaro89

OK, i cranked up my fuel pressure to 16 psi (as high as it would go) and from the thread i saw yesterday 16 psi on the holley TBI is 65 lbs/hr. So that brings me back to 128 for my BPC, and i will scale back my VE tables 10% and reburn a chip and run it a couple times tonight. Just a bit of info, when i cranked up my FP last night and gave it the gas, i know the chip in the car isnt right, but my throttle response came back (I know that statement is probably a no brainer) but i hope it stays with the new chip, I'll try it out and let you know how it does. Anyone let me know if the BPC calculation I did doesnt sound right, thanks!

BMmonteSS

You’ll probably have to run a slightly higher than calculated BPC to scale your VE tables back. So if your first log shows that your universally lean, try bumping your BPC up 10 points to 138 and see your BLM’s will fall back in line.

It’s good that you noticed your throttle response was better with a rich tune, it won’t be that way once you change the BPC. Since you’re basically canceling out the FP change with the BPC. This is not a problem, it just lets us know that your pump shot is way lean. I would go ahead and try doubling your pump shot both TPS and MAP tables. I know this sounds excessive, but it will guarantee that you’ll be rich off idle rather than lean. It’s much better to start rich and lean it out. I had to make some major changes to my Pump shot tables with my motor, with the big throttle body you introduce so much more air faster when you first open the throttle there is no way stock pump shot settings can cover it.

xjcamaro89

If i have to up my BPC by 10 to get my BLMs to fall back inline, once i get them back inline do i leave my BPC where it is at or drop it back down 10? i know its probably a stupid question but I want to know.

BMmonteSS

You have to remember that the BPC is just an injector constant and cylinder size rolled into one. If you increase the BPC it will richen the tune, decreasing it will lean the motor. Try to think of fueling as this simple equation. (It’s no where near this simple, but it works for visualization purposes)

BPC x VE = PW

Ok let’s assume your injectors are going static at 4000 RPM’s. At 4K you have 7.5 milliseconds to inject all the needed fuel. Let’s say up until that point you’re supplying exactly the right amount of fuel, but you simply run out of time to inject the needed fuel above that point. So you increase your FP to increase the amount of fuel you inject while the injector is open. So now you’re still going to go static at 4K rpm because the ECM is still going to calculate that it needs to hold the injector open for 7.5 ms. The only change you made was to make your perfect fuel mixture rich. So to fix this we will lower your BPC or your VE, it won’t matter which because they both affect the calculated PW, until your AFR is perfect again. Now at 4000 RPM you’re going to have the same perfect AFR and only have the injector open for 4.5 MS because we lowered either the BPC or the VE. So by dividing 4.5 by 7.5 we see that our duty cycle is 60% and is way safe. We can now go all the way to 6000 rpm before we start having problems with the injectors going static (using the formula to calculate available PW we get 5 ms @6000 rpm which is 90% DC). Of course this is simplified and I don’t really know what your PW is at 4000 rpm, that’s why we need to log and find out.

xjcamaro89

OK, ran the car with 138 BPW, ran it 4 times and made changes everytime, now the car runs good, throttle response is still there (I uped the TPS vs MAP and Wall wetting tables, once a little too far because it bogged down) I am going to see if it idles good from a cold start after work today, but im assuming it will. I still feel a slight power loss in higher RPMs still , but not like before. Will changing the timing and setting the VE tables again get rid of that, because last year when I ran the car i had to advance the timing really far and it would run great, and i mean good, like awesome acceleration and power through all RPMs, but it wouldnt idle right, and that was with the 10 PSI of fuel I had been running, so I think that when we get to changing the timing that my power will come back. But if we have the FP as high as it will go there probably isnt anything else we can do with it right now, so i wont complain about it. Im attaching the bin and logs, take a look at them, BMmonte you can number them whatever you want, i just put the date with the bin file. Let me know what you think. See if we are ready to move on. And i just want to let you guys know, in the next coming weeks while we work on this project I might not be able to make runs every night like I have been doing, there is alot of stuff going on in the next couple weeks for me, but i will try to squeeze in runs when I can, but if you dont hear from me for a while dont get worried, im not abbandoning this thread

xjcamaro89

The rest of the files:

BMmonteSS

Ok your blm’s look pretty darn good. NOW it’s time to start working on making some power. We should be able to take some shorter data logs now that we’ll be playing with WOT stuff. I noticed in the bin you sent me you reverted back to a bin file that didn’t have the VE#2 flat lined or the PW in the ALDL stream. I’m attaching a flat lined and PW modded version of that bin file, as well as a bin file (XJ5) that has the high load and high RPM parts of your VE curve smoothed out and closer to what I think they should look like (I’ve attached before and after screens shots). I also flat lined your WOT AFR table at 12.5 to 1 to start out at. They’ll be off, but they should be closer than what was there and will at least be on the rich side of things so we’ll be safely rich instead of burn a piston lean.

The first thing I want to do is try to log some high load and rpm parts of your VE curve to see if we’re even close. I would get the car warmed up, and then do some acceleration runs in 2nd or 3rd gear from 2400-4000 rpm but make sure you don’t engage PE mode. I’ll go ahead and set the enable point to 80% throttle, this should let you get to most of the 80 and 90 KPA cells. You’ve logged all the cells below 50 KPA pretty well we’re interested in the cells above 50 KPA. Don’t worry about getting all the cells we’re just looking for a good indicator of where we’re at. We’ll take some educated guesses once we have some data. You can also do a full throttle pull with PE engaged to get an idea of where your O2 sensor volts are and what your PW is at high rpm. Lets keep the rpm’s below 5000 rpm and if you notice your O2 sensor is reading lower than .700 volts at WOT stop and we’ll tune the VE some more before we try it again.

Next up….The better WOT AFR’s, timing and a whole lot more power.

BMmonteSS

Screen shots of WAG'd VE table

r0nin89

BMmonteSS

That's correct

r0nin89

bluzman2004

Hey BMmonteSS,
Can you explain the swapping Spark Advance and AFR into the ALDL path? I really would like to look at this in the log, but I can't seem to get it to work.
BTW, you are doing great job working with XJ on this.

xjcamaro89

I hope to make a run with the new Bin that BMmonte provided me with tonight and post tommorow. BMmonte how do I know when I have engaged PE mode, or how do I avoid it, thanks!

Ronny

iTrader: (1)

you enter PE when the %TPS is exceeded that is listed in constants. i believe stock is about 70%. mine is set 50%. hurts gas mileage but helps crutch the AE routines. i once disabled PE to work on the higher rpm/map ares of fuel tables but not recommended as damage could result if you forget to reenable PE. anyway it proved i was lean in those cells(140). so i fudged the cells i could not get hits on assuming those were lean too.

Monte. i may send you my .bin so you can critique it. just for laughs. cant do from office as my Company corrups it. will need to do from my daughters residence.

91RockS

On the topic of datalogging and tuning VE’s . . . . I've datalogged about 75 miles during my daily commute for the past two weeks. Here are a few observations that may be helpful to guys new to tuning their VE tables:

1. As BMmonte has said in this thread, be very easy and smooth on the throttle while datalogging. Avoid the temptation of stomping on the throttle. It is easy to get lots of datapoints in 50-60 kPa cells and below, but populating the cells above 60 kPa is harder since you can rarely stay in any one cell more than a few seconds at a time (unless you're climbing a big hill pulling a U-Haul). Gently roll in and out of the throttle to fill in the upper cells as best you can.

2. Related to #1, stay out of PE (power enrichment). Raise your PE Enable TPS to 75 or 80% to help with this. You'll want to revert back to a lower enable tps for normal driving.

3. Be careful to look at the number of counts you get in each cell before adjusting the VE’s. Cells with only a few counts may not be very accurate as they may have been captured during a transient condition as the engine was rapidly accelerating or decelerating. Look for trends in the neighboring cells and avoid making holes or spikes in the VE map.

4. To get the most consistency run to run, let the car warm up to the thermostat regulating temp before datalogging. Logging on a cold engine that's warming up produces inconsistent results.

5. Be consistent with the brand, type (standard vs. reformulated), and octane level of the fuel used. If possible, fuel up at the same gas station and use the same octane level. I've noticed a shift in blm's of 7 to 10 after filling up with the same octane rating, but purchased at a different gas station. I normally fill up with standard fuel (no ethanol), but occasionally have to fill up with reformulated fuel when in a metropolitan area where 10% ethanol is required in all fuel grades. The 10% ethanol pushes my blm's up about 10.

6. Limit what you change with each bin. If you mess with too many parameters at one time you won’t know which one caused the change.

7. Take good notes each time you datalog. I use a numbering system to create a unique name for each bin. Take notes about what was changed from the bin it was created from, and also the note the results from the datalog. Keep archived copies of each bin so you can go back to it later if needed.

Getting the VE tables nailed is challenging enough without chasing your tail with other variables that you can control.

dimented24x7

iTrader: (2)

Since the later PCMs are true speed density systems, they dont have a BPWc. Instead, they have an injector flowrate. Its located at 0x4D88. This double byte term is the grams per second flowrate of each injector x 819.