JeepYJv8

ok here is 1 line from a recent log

Map 43.9
TPS 12.4
RPM 2000
02 volt .477
int 119
blm 119

I dont get it! shouldnt int say hey were good and read close to 128 here? sometimes my WB02 is showing me pretty lean like 15-16:1 but showing up like 120 blm or less. what am i missing here? my wide band 02 feeds both my AFR guage and ECM 1227747! but the #'s arent jiving

Secondly i changed my PE WOT to 12.5 cause im shooting a #50 NOS my wide band is reading about 13.7?? are my injectors maxed out? it just doesnt seem rite.. Any ideas what im doing wrong?

PS this isnt just with nitrous!

RFmaster

You may want to ZIP your complete data log and upload it to this thread. It is not possible to get a full picture of what is going based on one data log snippet. Since both BLM and INT are reading 119 counts it indicates that ECM has to reduce amount of fuel from what is stored in your VE tables for a given combination of RPM and MAP values (and other variables). ECM was able to lean out fuel mixture based on NBO, but it is close to its adjustment limit.

//RF

JeepYJv8

well i think this is my answer! if my fuel tables are off will create my problem. i think ill start by tuning in open loop until i get my tables close!

I stole this info from someone

VE – Volumetric Efficiency is a term that corrects for different engine efficiencies. An engine is basically an air pump and the better the pump, the more power it can generate. Some engines are better pumps than others at a given RPM and MAP condition, so this term allows the equation to be calibrated for different engines. This is the single most important term that a speed density EFI system is famous for. There is a table in the ECM EPROM (chip) that gives VE for a given RPM and MAP condition. The important concept to grasp here is that the VE table is used in both open and closed loop modes, and essentially all modes. What is not so obvious to a novice is that this table, when programmed correctly, will result in a 14.7 A/F ratio with no closed loop or open loop correction taking place. In other words, this table provides a baseline that tells the ECM where 14.7 A/F ratio is so that other A/F ratios can be commanded and the ECM will be at the desired AFR. When this table is adjusted correctly, the engine runs the smoothest, not because the engine is running at 14.7 necessarily, but because all other ratios depend on this table being accurate. If this table is off, the closed loop term will correct the A/F ratio back to 14.7 to a degree. If this table is way off, the closed loop term can’t compensate and the engine may not run period. A good example of when this table needs adjusting is when a hot cam is installed. A stock cam typically idles at 17 inches vacuum. But a hot cam might idle at 12 inches or less of vacuum. The VE table will be calling for more fuel at a lower vacuum reading (higher MAP), but the engine doesn’t need the extra fuel because its still idling. In this case, the calibration doesn’t match the engine’s airflow characteristics. Unless the VE table is changed to lower the efficiency at this MAP and RPM, the engine will run very rich and probably stumble and blow black smoke. The majority of retuning a GM EFI system for non-GM and non-stock engines is done in the VE table since this is the baseline of the entire system. See Figure 1 for a sample of this table.

doc

Exactly, what is it that you dont understand? As RF said, the ECM has taking fuel away from what is normally calculated for the specific MAP/RPM fuel cell that you are in, given the 119 value for BLM. So what you do is to locate the appropriate VE cells that pertain to the 119 BLM, and lower the values about 5% (in other words, multiply thru by 0.95). Program a new chip, and go out and log some more. If you do it right, the BLM value should increase and be closer to 128. Remember that you have 16 fuel cells, you only want to change the section of the VE map that pertains to the BLM thats at 119. Of course, you will want to smooth the VE table out.

doc

I never tune in open loop mode. How can you tell what you are effecting when you dont let the ECM tell you the changing BLM values. If you tune in open loop, you will have to reset all of the BLMs and INTs to 128 and lock them there, and rely solely on your WBO2 sensor. Which is OK I guess, but I never do it that way. I use my WBO2 to tell me the AFR while at WOT. I let the BLMs to guide me to tune my MAF tables (I dont have the VE tables, as you do). I was doing just this earlier tonite.

JeepYJv8

in my first post i was trying to show that the WB02 voltage that feeds the ecm is 14something :1 AFR.i dont use a Narrow band at all on my motor. i felt the int shouldnt be at 119 if my afr is that close to 14.7. at 119 that tells me its making a pretty big change ......BUT im just not taking into consiteration that the ecm is correcting AFR so i see it running perfect but its working to keep it there! thanks for your replys i was just humm well not thinking

JeepYJv8

i was also looking at it like this! when my blm was 128 in x and y cell. i felt its @ 14.7 in that cell but if that cell said 120 i figure its running rich and looking for int to increase and subtract fuel to bring it to 128.

that being said if may AFR guage said 14.7 i expected the blm cell x&y to be @128 and the int as well.

As i mentioned earlier, i really dont know what i was thinking!!! sorry for waisting time!

PS that being said! how would you tune without a Wide band 02? i would think there is no way to get the block learn# +/-3 of 128 with a narrow band 02. i had an AFR guage that hooked up to my stock 02 and that thing was all over the place

Ronny

iTrader: (1)

I do not tune BLM with WB. I use a heated Delco NB02 sensor. Others tune VE with a WB so personal preference. I believe RBob suggested using WB is faster method and WB is reporting with great accuracy.

Quote: If you tune in open loop, you will have to reset all of the BLMs and INTs to 128 and lock them there, and rely solely on your WBO2 sensor.
That us my understanding. When you lock OL I would suspect to see 128 128 128 in your datalogs. On the Innovate website there is info on how to use WB as a NB. Probably here too. Something tells me you CAN however use WB and be in CL as well. So your 119 BLM indicates that VE cell needs to be changed.

Others patch the datastream of WB into logs for reference. I will do that next tuning season.

Your VE values and BPC inpact PE A/F.

Is your N02 wet?

JeepYJv8

Ronny thanks for your reply! i will try and get that worked out.if i disconnect my WB from the ecm i believe it locks the blm's @ 128. I would just like to see how it performs without the ECM adjusting everything. tuning for me is difficult the way it is. I mean all the different variables like coolant vrs spark advance just to name one always changing something. I just want it to sit still for a moment.. i guess this may be a reason why people ditch the computer for a carb!! anyhow

what is the difference between BPW and BPC?

im sure im due for larger injectors, im running 55's lb injectors with fresh rebuild, cam,headers,full exhaust, and nitrous! (stock pump)!! tonite i will try and tune using the BLM's and not the WB redo my BPC and see if everything looks more accurate. then hopefully i can bring my PE WOT down to 12.5:1 AFR

I run my NOS dry! its easy and a great way to get gains when you need it! i will convert it over to wet eventually. Holley sells a kit to convert a dry system. on the other hand i have all required to run wet but feel its not needed 75HP shot and under..

doc

Ok, to reply to just the BLM at 119 and the WBO2 near 14.7,,, thats the way the ECM works. The ECM via the WBO2 had detected a rich condition and started to reduce the BLM value. That process would continue until the BLM value drop far enough, taking enough fuel out of the original calculation so that you reach 14.7:1 AFR.

Now as it stands, your ECM corrective capability is nearly out of range. You should alter the VE table to bring the BLM value closer to 128 which is baseline. I explained how you would accomplish that in one of my posts above.

Ronny

iTrader: (1)

Doc is right on. You need to look at datalogs and adjust the VE tables to get all cells in ballpark 125-131. Odds are you are rich globally or maybe just rich in a few cells.

BPC is the first change you make in .bin. BPC tells the ECU what your engine is. BPC is based on CID-FUEL Pressure-Injector size. If you have niot yet changed it, it is then set to whatever the stock is for that specific chip(.bin). BPW may be same. Not sure. PW however is injector u-sec on.

I dont see how you can possibly run N02 dry. N02 when compressed releases quite a bit of 02 and will run the WOT-PE and AE excessivly lean. You can "crutch" the PE-AE by changing tables but not sure how that will work out. Is your mask allowing RPM based PE so that you can just adresss 90-100% TPS?

doc

You should have two tunes, one for no nitrious, and a second with nitrious. As mentioned above, the NO2 will get you alot more oxygen, you need more fuel. Therefore, a separate Eprom chip for nitrious is a good way to go about it. You really cant do it properly with one tune.

Edit: I thought about this a bit more. I think that it might be possible with one Eprom chip. For the times that you are not running NO2, you could get things setup so that you are running 45 psi (just for example) and tune the VE table to get you BLMs around 140. Then when you know that you are going to run NO2, you turn up the fuel pressure to (lets say) 50 psi, and let the ECM correct the rich condition while just driving around (not in WOT). The BLMs will fall to below 128, I assume, maybe around 115. However, now with the higher fuel pressure, you would get the extra fuel you need in PE mode when you turn on the NO2.

JeepYJv8

Doc Thanks for your reply!

I do have multiple tunes, i have the moates ex remote so i can switch from tune to tune on the fly. I just thought maybe i could use PE WOT AFR to create a fuel curve that can accomidate the small 75 shot im using. im just not sure i want to run NOS all the way through the mud pit. they put a nice hump in the pit , WOT & NOS i may get myself in trouble!!!

Ronny

iTrader: (1)

Doc: The issue with cranking up FP to account for needed enrich for PE is that it will mess with other tables such as crank-choke-OL vs coolant-AE- IAC fuel, etc.

when my N02 is installed this tuning next season I will use only one N02.bin as I will alwys have a full tank in my car and a spare in garage(just like my gas grill) !!

JeepYJv8

Well I adjusted fp last nite. 13.5 to 19. Recalc bpw. It ran good. And the nos hit hard. And was running 12.5:1 afr @ wot while spraying. This morning it was cold well cold for south Florida! And it started but didn't idle high like it normally does and ran like garbage. I drove it a few miles it warmed up some and ran better but once I got back i checked fp and it was back down to 14 psi. Grrrr I modded the stock regulator to make it adjustable. Bad idea!! I don't know if the screw vibrates back out or what happens. But I need to do an afpr and ditch the stock one.

Anyone using aftermarket amfpr? Does it go online with return? Will the vacuum advance port work to increase fp? My nos kit is vacuum referenced so it can raise fp when I'm spraying. It uses a vac regulator with an adjustable jet!! I'm writing from I phone so please excuse my grammer!!

Ronny

iTrader: (1)

I use VAFPR Aeromotive reg. Comes with 2 springs one lbs 20 and <, and another 20-60. I run the weaker at 19.5 lbs(80 lbs injectors) and VAFPR pulls it down to 11.5 at idle. So WOT is 19.5 as is key on engine off. Decreases FP. Vac pulls against spring/diaphragm I believe. I think it was created to help with idle needs yet allow higher flow WOT.

Aeromotive has locknut on screw.

EBL supports N02 but I have not looked at those tables. This weekend.

40ozthreat

Not trying to Hijack this thread, but I seem to be having a closed loop problem. I have been tuning in open loop with a wideband, and have gotten pretty close across the board 12-15 AFR respectivily and have good cruising driveability, but am still working on AE. However, when I enable open loop the BLMs start pulling fuel to the point that I am lean and my driveability goes out the window. I am running a new heated nbo2 seperate from my wbo2.

Is it possible that I am still not quite close enough open loop, or is it that there may be some rough transitions from rich to lean that cause the nbo2 to think its rich when its not?

The other thing that is noteworthy is that if I am incapable of switching my injector constant-which may be the cause of my woes. If I switch from the stock 61 to my calculated 96, I no longer have the adjustability in my VE tables. The VE tables would be maxed out at like 1200 rpms. Is there more thing constants that I need to adjust besides the TBI injector flow, or should I just give up on the $E6 mask?

1tpi

[QUOTE]Not trying to Hijack this thread,
But you did hijack it, you should start your own.
Thanks

JeepYJv8

How did you hook that regulator up? I'm guessing it goes inline on the supply side? Then block off return from tbi, and connect return to the new afpr?

I didn't get anywhere with it today, I went to nitro jam! I've seen some pretty serious fuel systems!!

40ozthreat,

I can't help you well cause mine does the same thing! I imagine you mean when you enable closed loop rite? Not open loop. I've been told you must have ve and bpw inline for it to function properly. But I'm with you on well if it runs well in open then it should run better in closed! Keep me posted!

40ozthreat

Yes I did mean closed loop. I have been tinkering today with the ae and decel enleanment. Im going to try to focus on getting a nice smooth line in the general stoich vacinity. My assumption is if I let off the throttle there is not enough decel enleanment, and my afr stays high at low rpm low map. Now because of the excess fuel in the intake that burns after deceleration the ecm thinks it is rich at the low rpm low map and adjusts.

I think that tommorow I am going to go find a nice long empty stretch of road so I can really ensure that my ve table is close. I have been trying to tune in a neighborhood so it is hard holding it at a certain load for a while. I think that all the accelerating and breaking in town can make me wrongfully adjust for rich and lean conditions that don't really exist, just like the blms do.

JeepYJv8

I think your on the rite path! That does make sense. its funny you say decel enleanment, i noticed yesterday i let of gas to basically coast to a stop . i noticed my blm got leaner and leaner until it got up to 22:1 Afr which i imagine not enough decel may not be helping. mine also does the same as i excel bouncing around going lean.

I think you should calculate your BPW to your setup and play with AE tps and defiantly ae map as well and decel as well, i think BPW is one of those tables like Static timing "it is what it is" and thats it! though i am not great at this, and just trying to help! keep me posted! i will play with mine today as well i think i finally got the fuel pressure to hold at 15psi now ill try tuning some more! good luck!

40ozthreat

Well I definately got close enough to get back into closed loop. I did runs in open loop trying to hold it around where there appeared to be trouble spots. I have gotten a little closer with my AE and my Dec Enl as well, which are big players in how you make fueling adjustments. I did a lot of really steady cruise tuning, then I would chop the throttle to see how it would react going back to negligibly the same cell. Watching these logs provided plenty of insight on the ae and de tuning. It appears that DE is the exact opposite of AE.

I am having the same issue as you with the my afr going up to 21 on decel, but just looking at a log it is rich before it goes to 21 at the same map and rpm. So I am probably rich in that cell causing fouling to the point that its burning so innefficient thus more oxygen content in the exhaust gas. This would only happen on an extended downhill when I downshifted. This would happen at the same time, I believe right after my DE MAP ran out, so I think that cell may on the ve table may be too fat.

With the injector flow constant, my initial thought was that the it is set it and forget it. However, I am a little concerned about how it works in a dual plane with the IAC. Does it adjust the IAC side accordingly during operation? The reason Im a little concerned is I checked my plugs and there is a difference depending on which injector the cylinder is firing on.

I feel that I made some progress this weekend, but for every step forward I make half a step back. I seem to be haveing a problem with my upper radiator hose collapsing and causing overheating. Have tried a couple t-stats and it is the same pump, same newer radiator and cap and I am a little stumped. I will have to give it a pressure test when I get the chance.

JeepYJv8

Updated!!

I started this thread almost 1 year ago. I was confused why my wide band would read 14.7(as commanded) but int would be at 119.(which tells me its still subtracting fuel). this led to lean WB02 reading's and stumbled alot, along with high temp. Also if i commanded 12.5:1 AFR @ WOT my wideband would read 14 or so AFR. my WB02 also feeds the ecu, just keep that in mind.

I asked this question, but wasnt clear enough on the actual problem. It came to the point where i just kept on subtracting fuel until i had 128 readings. but my WB was always showing 15-16 AFR. It didnt run well.

Here is where the root of my problem started. i swaped in the l05 along with the 7747 out of a GMC jimmy, Into a jeep wrangler. I never knew the origional FP of the gmc so used the 135 BPW from the factory tune. i read the origional fuel pressure set from gm was between 10-13psi, so i calculated mine using 12psi figuring that was the factory pressure.

So i gave up on the tuning for awhile, figured it ran good enough. I was winning and life was good.

the past few weeks i started all over again, trying to figure out how to gain performance. and my first order of business was the WB reading's being accurate. I spent alot of time toying with the BPW. i realized this changed " how accurate my WB02 was reading. Being i use a tune switching remote, i used 8 different BPW calculations and switched between them to see if my commanded afr got closer to my int/blm. this took alot of logging and tuning but i slowly was gaining progress! after lots of logs low and behold my ecu and WB02 are in sync!! i now command an afr and thats what i see on the WB02 and it runs 10x better, with a big gain in performance. i ended up adding about 15% fuel when before it was telling me it was rich. It feels like a totally different motor.

Conclusion
I think its extremely important that your BPW/BPC is calculated correctly. this has drove me nuts to figure out. and i know some of you are not running wbo2's. so you may never know if that # is correct, maybe someone with more experience can explain the how or why? but i know it worked for me. I now have a huge gain in performance, and my motor runs about 10-15* cooler.

Ronny

iTrader: (1)

Just for the heck of it post your CID(350?) fuel press and injector values. I will run through my calculator and see what I come up with.

JeepYJv8

Ronny, The engine is 350. also the injectors are the stock GM 55lb injectors.( i cant think of the exact part# at the moment. I moved the fuel pressure back down to 12.5psi to try and eliminate parts of the equation.

The factory BPW was 135. i changed it to 140. thats where everything seemed most accurate. but the next day it was slightly off again. But still running a lot better. It must be some other variable. i think i need a good regulator for fuel, i have a strong pump in there, it's rated x2 of the factory pump specs.

I understand the static portion of running my injectors. I will bump it back up again. I made my factory reg adjustable, but i need to invest at least into the jet model. I also recorded that my PW was 90 @ idle through the aldl. I know there is a formula for this, but havent got around to it yet. Not sure if that helps with anything

Ps. this motor is all torque, i back it off @ about 5k maybe 5200,my sfift light flashes at 4500. but i will spin it faster in the future.

P.s 4:10 gears and 35" tires. Not sure if that's useful either. but its here if you need it. i will upload a log just in case anyone wants to look at it. just keep in mind i just changed FP so it may look pretty bad. since its not exactly street highway speed vehicle. and its dead flat here, so hills are out of the question

JeepYJv8

Here are some files. keep in mind at 40mph cruising and about 2k rpm, My WBO2 was reading between 15.5-16.2. and the blm's were low around 119. But once i get into throttle, it feels good and they lower into the 12's.

xch3no2

Or you could download RBob's TBI-BPC calculator from here http://www.tbiparts.com/
& use it yourself endlessly.

JeepYJv8

Thanks for the link, i have a couple of these, and never get the same result. Here is what's a bit strange. my stock tune is set to 135 bpc. From the factory the Tbi fuel pressure was between 9-13 PSI. using that calc on near stock psi/tune it comes up completely different.

@9 Psi = 182 BPC

@12 Psi = 157 BPC

Stock Cal was 135 BPC

So those #'s are way different than my BPC that GM had stored on the ECM. But ill try them out and see what happens for the hell of it. Rob is the king of tuning, like michael jackson or Elvis was to music!! .. I'm not Scarrrred! haha. Since i leave for north in the am, i will swap the BPC and see what happens tonight!!

JeepYJv8

Alright, before i burnt some tunes on the chip i went out to check the FP. I set it at 12.5 PSi the other day. Well now it crept up to 16 PSI. I need a way to fix my FPR. I made mine adjustable, and that's just not working out,

Solutions anyone? Anyone use that jet reg and have steady consistent FP? I really dont want to spend a couple hundred on the aeromotive setup with plumbing. but i will if no other choice.

So i burnt the chip using rob's calc and the 16 psi # . It ran good and matched the WB02. I guess the FP change is whats killing me. It looks like it needs quite a bit more fuel in the tables, it knocked a little. but it ran good. I just need to get the fuel reg figured out before i continue tuning. I'm including the log file, if anyone's interested.

Ronny

iTrader: (1)

Not sure how to fix that. I will suggest a FP read is valid only on cold engine. Heat may affect reads. I cant see the spring getting lazy or stupid with diff reads. Unless the screw does not have a set nut to lock it down?

i dont think having the BPC off a tad will hurt much. you can tune around that. as long as your VE tables are not maxed to 100. My calculator varies from the one on that site.

Wide latest shows more fuel needed in VE globally.

How does one read the .txt? The columns do not line up?

JeepYJv8

Thanks for the information about cold vrs hot fp readings. I was not aware they change. Does your setup stay rock steady. I hate dumping more cash into something I hardly drive. But I really want my fp as stable as possible. My $3k jeep is now nearing $15k. In a little less than 2 year time. I welded
A nyloc nut inside to eliminate it from coming
Loose, but maybe it is moving.To answer your question there is no nut holding it, just the nyloc nut. I didn't use a nut since it's extremely difficult to adjust without ripping off the tb to adjust. I'd like to be able to watch fp while driving, but im currently running mechanical guage, that sits under hood. Maybe I'll look into electronic sending unit. Since rules
Are no fuel lines in the cab. One day it logs rich then next day it may read Lean. Before I changed that bpc, my logs were rich. This one way lean, but the power was still there. I get back dec 30th. I'm defiantly enjoying tuning again after this power gain


The txt files are acting weird. I do have a new laptop running win 7. With excel. I usually just open them as an excel file. But now I get an error. So I've been copying into notepad or word, then cut n paste to excel, and it all lines up and works Would some other format be easier?

JeepYJv8

Thanks for the information about cold vrs hot fp readings. I was not aware they change. Does your setup stay rock steady. I hate dumping more cash into something I hardly drive. But I really want my fp as stable as possible. My $3k jeep is now nearing $15k. In a little less than 2 year time. I welded
A nyloc nut inside to eliminate it from coming
Loose, but maybe it is moving.To answer your question there is no nut holding it, just the nyloc nut. I didn't use a nut since it's extremely difficult to adjust without ripping off the tb to adjust. I'd like to be able to watch fp while driving, but im currently running mechanical guage, that sits under hood. Maybe I'll look into electronic sending unit. Since rules
Are no fuelQ- lines in the cab. One day it logs rich then next day it may read Lean. Before I changed that bpc, my logs were rich. This one way lean, but the power was still there. I get back dec 30th. I'm defiantly enjoying tuning again after this power gain


The txt files are acting weird. I do have a new laptop running win 7. With excel. I usually just open them as an excel file. But now I get an error. So I've been copying into notepad or word, then cut n paste to excel, and it all lines up and works Would some other format be easier?

RFmaster

I use Jet 61500 adjustable FPR - it's rock steady (hot or cold) and I have data log files to back this claim. In my fuel system I have fuel pressure sensor (Autometer 2239 0 to 30 PSI) which together with ZT2 provides a good EBL based data capture system.

//RF

Ronny

iTrader: (1)

One day it logs rich then next day it may read Lean. Before I changed that bpc, my logs were rich. This one way lean, but the power was still there.

I presume lean is as being read on WB which is considered accurrate. WB shows factual lean. Lean BLM is not really lean. It is stoich(14.3 E 10) even if adding fuel at 119 or whatever. Just my opinion with terminology.