cool thanks for the answer i'm getting one of these myself . my last car which was turbo's when i tuned i tuned maps . i see i got alot to study here still .thanks for the info tho

 

I changed my BPC to 95 that equals to 21 psi at 75# / hour. Holley specks the 670 Cfm injectors at 85# / hr. @ 21 psi. My tables look much better. I also changed to the ebl_f_2010 from the ebl_f_2011.

I did stay with the 84 BPC on the new ebl_f_2010 but it ran very rough but seems to be running smother on the 95 BPC. and the VE is moving less and it looks like ill be avoiding my 100% in the ve's.

I would like to know from ROB the Difference between the:
ebl_f_2010 and the ebl_f_2011.

Scott

1988 1/2 Ton 4 W/D Suburban
383 Stroker (Roller)
Performer Edelbrock Manifold
670 CFM Holley TBI
3" Exhaust No Cat(shhhh), Flow Master 40
190 LPH In-tank Fuel Pump 21 PSI
EBL (Dynamic EFI) Computer

 

If you're using TunerPro ( most of us are ) there is a diff tool that will tell you the differences between any of the courtesy bins, or any others that use the same XDF file.

 

Some background for our readers. GTA started with the injector flow rate of 24 #/hr, which is what the injectors are supposed to be. The result was a dramatic lowering of the VE tables in the low RPM areas (< 2200 RPM).

The original cal had the injector flow rate at 28 #/hr, so we went with that. The low speed VE is much better. Fell in line quickly and the car is very driveable.

Since the injector DC% at high RPM/load is only up to 70 there is still injector left to use.

I would drop the injector flow rate constant to 26 #/hr. This will add fuel across the board. So VE Learns are going to be pulling fuel (lowering the VE) in the low RPM areas again.

While this is being done check the high RPM/load areas for the proper AFR (12.4:1 - 12.8:1). Along with the DC%. Once the DC% gets to 85% or higher then the injectors need to be larger.

If the AFR comes into line along with the DC% staying at 85% or lower, you are good to go.

RBob.

 

Rbob,

Thank you for the reply, I am going to give that a try today, I am again going to use both the BLM-closed loop and the WB -open loop to have the VE table fall back to where it needs to be, Oh after a closer inspection of the latest data log the INJ DC hit 86% at 4000+ rpm This seems very strange to me as i would tend to think that a #24 Inj set to #28 in the bin "Should" be able to meet my fueling needs no problem, But I am going to go to 26, then to #24 if need be, Thank for your input and i will report back later with the results, GTA...

Oh, BTW what does the BPC vrs vac table do? All the values are at 255 ? thx

 

So, If I'm seeing 65% DC then Ive got some work to do.

 

Don't underestimate what Bob is alluding to here !!
Once you start seeing injectors trying to run 90% more or less, they tend to go erratic.
What's happening, is the closer you get to 99-100% the more time the injector spends just opening and closing, or trying to, and not flowing, so you lose control over how much fuel they are flowing. They tend to lean out, as half open flows less fuel than full open !
Somewhere above 90%, they'll go static, where there simply isn't enough time for them to close before they are commanded to open again, so they basically stay open, and flow A LOT of fuel ! Again, you essentially lose control, possibly going rich.
It's not that the injectors can't flow their rating, it's that as you get close to their maximum rating you, lose control.

 

Not yet.
Above about 85% more or less, you'll be needing bigger injectors, higher fuel pressure, something to increase the *availability* of fuel, whether you actually use it or not.
Depending on the range, when you do this, you may lose control at the low end.

 

I would like to know if this is right direction to go.

The funny thing is when I was running 13.5 psi with a different fuel pump I had a DC% at 85 at higher rpm. The ve didnt hit 100% and I was headed in the right direction.

I did the Fuel pump change and put in the recommended values from Holley and 100% all over the place. I did start with a new profile.

I did not see any documentation here or in The EBL docs. that said to start changing the BPC number to get a better range.

I will say that a .pdf manual listing the primary issues that Most run into when some of us have NO tuning experience but are wanting to learn would be nice.

If ive missed something then my bad. getting info is a bit tough in a News group like this.

Still plugging away and I love this product..

Scott

 

Well, ive started all over fresh.

I did a new profile ebl_f_2010, went from 84 to 95 in my BPC. I did shut off my EGR and CCP. I also did the HiWy - Min so to keep the learning going without hitting the lean cruise. SA is at 3.16.

 

Larger injectors are required. That is if the AFR of 13.8-14.2 is true. As cflick mentioned, once the DC% goes above 85% you are out of injector. No futzing of the calibration will get them to flow more fuel.

The BPC vs VAC table doesn't exist in the EBL P4 system. Double check that you are using the correct XDF file. It should be "EBL_P4_V10" or "EBL_P4_V10_ADV"

RBob.

 

Rbob, I made 2 new data logs...i cant get them uploaded here So i am sending to your reg e-mail...if you would be so kind as to post them up for me, and we can keep everone in the loop and hopefully this experience can help out a few others..... GTA...

 

You mentioned hitting a DC% of 85 int he post before this one. Once the injector duty cycle (DC) reaches this point more injector is required. On TBI it is easy to increase the fuel pressure for this. That is up to about 30 psi.

The BPC is just the engine displacement and injector flow rate rolled into one value (or table of values). If the DC% is less then 85, and the VE is reaching 100%, and the AFR is on the lean side. The BPC can be increased to increase the injector PW.

Think of the BPC as more of a centering device for the VE tables.

The key is the DC%. The BPC can be changed, but the restraining factor is the injector DC. It shouldn't be more then 85% at high rpm & load.

Note that with lots of AE it can easily exceed 100%. As long as there is enough AE I typically don't worry about it. Although the AE should be reduced as once at 100% no additional fuel is or can be added.

RBob.

 

I hit the 85% DC with the old fuel pump and pressure. 13.5. Im now at the 21 psi and new 190 LPH pump. So, safe to say if I dont raise my fuel pressure, then raising my BPC from 84 to 95 is an acceptable way to stay out of the 100% in ve therefore giving me the injector range i need. If I still have a lower DC% then I can increase fuel pressure and lower BPC until I get a fuller range of my injector?

Scott

 

.

Couple things I wanted to see addressed here....

Suggesting you were out of fuel *control* at that range, but do you run there ?

I'd say you did two things "wrong" here.
1. Used Holley recommendations instead of calculating your own based on fuel pressure and flow capability.
2. Started a new "profile." ( I assume you mean a new sample calibration ? )

1. All you needed from Holley, is that the pump is capable of the volume of fuel you need while maintaining pressure at that volume.
2. A new profile means to me, that you've introduced a LOT of variables on top of the pump change.
That would confuse even the best tuners. It means that you're starting over from scratch, and know nothing about what direction to go.

Understand what BPC really is.
It's a BASE constant for the injectors. A starting point from which the ECM can work. Ya gotta start somewhere ! If the ECM can't calculate how much to vary from a base starting point, things get much tougher.
Changing it won't necessarily get you more range, but it will move the entire range up or down. If you are running out of command at one end, but have room at the other, then changing it is an option. As Rbob said, think of it as a centering tool for the VE tables.

EBL is a tool, and a really, REALLY great one, IMHO.
It's NOT a course in engine tuning, nor is it a short-cut into top fuel !
The base EBL was a HUGE step in providing us with means to accomplish things we could not previously. EBL FLASH makes even that so much simpler, there's not much comparison with anything that came before. Still, it's not a free lunch.
The "primary issues" are different for all of us.
For you apparently, it's your introduction into engine "fine" tuning.
For me, it was starting with an engine for which no profile even existed. Not even close, and finding the tools that would allow me to develop one.
I had to acquire an e-prom burner, and the UV light to erase so I could re-burn.
Many of the tweeks we can do with EBL didn't exist in the ECM's available.

For you, you can start with the stickies in the forum, and learn to tune.
For me, the documentation provided with the EBL is everything I need to know about it.

It's actually quite easy to get. Just READ all of the DIY EFI forum on this site !
Maybe not so easy to understand and assimilate.
There is more information, opinion, and experience on THIS site in this regard than any other collection in the world, to the best of my knowledge and belief.
As many years as I've been here, I still haven't gotten through it all.
There's documented experience. Experiments and results. Theory and practice. History, and references to other sources of even more information.
DON'T get in a hurry !!
Trust me, I know that looking at weeks of study can be daunting, and we tend to want to dive right in and see results. Diving right in, you absolutely will see results, but they might not be the results you want to see.
Take your time, and you may find this one of the most rewarding experiences of your life, as have some of the rest of us.

Just one guy's opinion........

 

Just zip the files and they can be up loaded. Here is the Bin59ol log file in two formats. The .EBL format is text and can be opened in Notepad.

The .CSV file is in comma delimited format for opening in Excel. Can freeze the top line/pane to retain the header throughout the log.

RBob.

 

By my calculation, you've gained 24% fuel availability.

What I would do, is calculate the correct BPC for the fuel you now have available, lower the entire VE table by 24%, and log the results.

Range of the VE table, not the injector.

The range of the injector is mechanical. ( affected by fuel pressure and such ) No amount of changing the calibration can change that, but it can allow you to use it to the best overall outcome.

 

Thank you!

when i try to zip and upload i get a "invalide file"...oh well its up any way.
Could a few folks have a peek at this and let me know what they think?
They are #24 FMS injectors, in a Modded 5.7 Super Ram engine that has AFR heads a very mild cam/ headders. I cant believe i'm out of injector! BTW my fuel pressure is aprox 47 PSI with vac disconnected. Can it be turned up or am i just very simply needing a bigger set of injectors? Thx GTA...

 

Couple things I wanted to see addressed here....


Yes it ran there. My concern was that in the 100% areas VE still wanted to raise 8-12 but was out of range.


I used the values Holley(injector Flow rate at 21 psi) 85 GPH at 21 psi. I put this into the BPC calculation Utility That gave me BPC of 84. My result was Not enough adjustment in the VE.

I did start all over. It is the ebl_f_2010 instead of the ebl_f_2011.

I thought since Ive learned that the BPC is basicly a centering device I thought I would start Fresh and move my BPC Only...as to get into a better range in my VE tables. Then once thats done. I will look at AE and start tweeking the flat spots and the MANY other options EBL provides.

I am trying to get a good foundation first. Then ill move 1 thing at a time from that point on.


This I get and am glad its been explained in this manner.

Thank you so much for the detailed response and thoughtful help,

Scott

 

I want to clarify a few things:

When adjusting:
AE - MAP PW and AE - TPS PW(Pulse Width)
Increasing the uSec is increasing the amount of fuel correct? In relationship to MAP or TPS %.

Scott

 

Yes. You may note other tables that increase/modify AE fueling. Of particular interest(to me anyway) was AE-RPM tables.

 

What is the relationship between the AE tables and the VE Table in Working in conjunction with each other?

Referencing a specific past posted response is Fine. I have read a few on it and am just making sure I'm understanding it correctly.

I have read past posts from Grumpy....and he seemed to use the AE tables for theses larger cammed v-8's as part of the fine tuning. seemed he would spend allot of time there.

Thanks,

Scott

just ran across this.....

https://www.thirdgen.org/forums/diy-...ps-vs-map.html

 

skerlock,
In raising your BPC you "told" the EBL that the injectors are smaller.
End result of the calculation is that they now deliver more fuel, and the reason your VE table moved.

I don't know if this is a problem w/Holley's injector rating or not, I suspect it could be.
Make sure your fuel pressure monitoring is accurate, maybe post details of your fuel delivery plumbing.

If BPC is not set to a correct value you will have problems with BLM/INT over or under correcting when in closed loop.

 

My range is much better looks like I'm going to max out in the VE around the mid 90's or so. I dont know what the DC%is yet.

I am running the stock lines from the tank to the TBI. 1 Fuel filter(New). The return line is stock.

Fuel Monitoring is the Actron Fuel pressure gauge with the "T" in lie at the entrance to the TBI. http://www.actron.com/product_detail.php?pid=16173

That help?

Scott

 

If what I'm thinking of Holly's injector rating is correct I think your on the right track.

 

Well, When I talked to them they told be that the injectors are 65# at 12 psi and 85# at 21 Psi. I put the 85# @ 21psi in and that didnt work as i wrote before.

Im at 21psi guessing @ 75 # at least in the BPC.

I was hoping that after I get the VE balanced. Ill watch the DC and if im a ways from the 100% in the VE and the DC% s low Ill enter a larger BPC value and see how that looks.

If I take a new BPC value and enter it into my existing profile will it change the appropriate values across the board in the profile? Like the PW values?

Scott

 

Last Q first, No. It changes only BPC based calcs nothing else.

Tho the info you posted is widely circulated for Holly's injectors it is not the behavior they are exhibiting.

Be sure that pressure is not falling off while driving.

 

I will take a guess on that and say none. I cannot locate the equasion that ECU uses to calc AE. AE is sensitive to FP and injector size. there are other modifiers as well to AE(big on coolant compensation).

If you go to Holley web site in install instructions for their TBI retrofit it will speak of their injectors on rating.

I am of belief the Holley rates their injs at 21 lbs. so 65#ers flow that at 21 FP. 80 #ers (not 85 IMO) flow that at 21 FP.

Here is where I am stumped. I am not sure what the Holley inj's are at lower FP. Only what they flow at 21 lbs. Dont think you can say Holley 65's are equal to GM 65. So how does that allow you to calc BPC for entry into RBobs EBL.bin for BPC? Not sure how to convert Holley to GM at 13lbs FP and get their rating.

Did this confuse you?
What did Holley tell you?

 

I see XCH responded! I believe changing BPC will affect only the VE tables and PE which in turn looks at BLM which is VE based .

I have changed it more than a few times and I believe my AE... choke... open loop ...were not affected.

 

I look for a BPC that allows my WB AFR to reflect my commanded AFR.

 

This is what Holley gave me for the injectors...

Holley 522-43 Electronic Fuel Injector

60 PPH @ 12 PSI
85 PPH @ 21 PSI

I was incorrect in typing the 65# instead of the 60#(my Brain memory has limited hard drive space left)

Scott

Ill look that up...

 

Commanded AFR, as in OL tabels

Beware the rabbit hole goes deep very quickly.

 

Are you using a NB02 sensor for BLM?

 

This is another concern I have is my Temp never goes above 185 F. I thought theses were 195 F systems. Think I need to look at a different thermostat?

Just noticed it a few days ago.

1988 1/2 Ton 4 W/D Suburban
383 Stroker (Roller)
Performer Edelbrock Manifold
670 CFM Holley TBI
3" Exhaust No Cat(shhhh), Flow Master 40
190 LPH In-tank Fuel Pump 21 PSI
EBL (Dynamic EFI) Computer

 

Me? I have a Bosch New if your asking me. Ahhh NB for Narrow band...OOps

Scott

 

That sensor Q was for XCH.

Never over 185F. That is odd. mine is always 180-200 with 180 therm WI. what state are you?

 

Montana...and its cold up here.

 

Ron,
Yes, she runs CL off the NB & I use the WB (Bosch & LC-1 to EBL) for tuning.

Mind the fact that my NB target voltage is high to compensate for todays fuel,...& the rat's love for it.

I calc my BSFC as high as .52 (very bad) and max efficiency maybe 92%VE.
This understanding of my build helps me be successful where other less experienced builders/tuners fail.

 

Can someone look at these for me? specific to the lower @ upper VE tables?
Mine look like a giagantic U Car runs pretty close to 128 in closed loop now if i could only get the data log to attach....

Ok, got the data to attach, If i could borrow a set of eyes to look this over it would be greatly appreciated, thank you!! GTA....

 

Wow I missed some posts lol...

Mine is running quite well now, I'm pretty much down to tweaking little things. I think I'll have to either lower my initial timing (I eyeballed the distributor when I originally installed it, never put a timing light on it... turns out it's at about 8ºBTDC) or replace the starter because I have some hard starting sometimes after it's warm. I have some very faint surging at extremely light throttle between roughly 1200-1500rpm (like below 30kpa), working on richening that right now, I'm not quite sure why VE was so low there to start with.




I have to keep adjusting the idle-area VE values because it starts surging otherwise. DC is around 2-3%, and pulse width is around .9mS-1.0mS. I've managed to get a reasonable a/r, but on occasion it still wants to surge, is there something I can do to take care of this outside of a VAFPR? The regulator I have is supposedly capable of it, but I haven't touched it since I put it on the truck, fuel pressure was exactly where I wanted it to be set (25psi).

 

At that small of a PW the injectors are right on the edge of being opened. Which is why it can be lean at times and rich at other times.

With the increased fuel pressure the injector offset compensation should be increased. This will help in getting more consistent fueling. Vacuum referencing the FPR will also help. If you do that just change the "BPC - BPC vs VAC" table to match.

RBob.

 

For the U, see part2 of the intro to tuning. About flattening out the low RPM/load corner of the VE table. This area is never hit so it doesn't learn in.

RBob.

 

Anyone know why a single wire O2 sensor would start looking like an EKG readout? Last night i was on a long drive and it started to pulse up and down constantly. The only time it does not do it is when in accelerating allot or foot off the peddle?

Scott

 

That's what it's supposed to do in closed loop !!
The ECM cycles fueling slightly richer, then slightly leaner than the 14.7:1 AFR switch point of the NB O2 sensor, and if the sensor is, in fact, following the commanded AFR, then the ECM knows that the BLM is where it should be at the moment.

 

This is the first time Ive seen it do that. I guess im at a better balance air fuel wise.


In that case I'm ready to Lower my BPC value some now. From 95 to 90. Any suggestions on Changing the VE tables a specific percentage to keep it close to a good balance?
Thanks,

Scott

 

95 to 90 suggests a larger inj was added or FP was added so ECU delivers less fuel. I would say add to VE table 1.055 but I tend to go overboard so try 1.04 and see how BLM responds.

 

Ok, I adjusted the offset by a couple hundred μsec, should I have changed it more or less?

 

Yes Ronny I am wanting to tell it they are larger injectors. I was hitting 100% with the BPC @ 84. 95 was a starting point 90 is a guess. Ive balanced it pretty well at 95 and see that there is a bit of room at the higher end of my VE tables. I am targeting the Mid to High 90's in my final balance for my highest values.

How did you figure 1.055? Im not questioning, trying to learn.

Thank you,

Scott

 

First, you need to know what the injectors flow at ANY pressure.
If it was me, I'd sink a fuel pump into a tank, and let the injector spray into a can.
Measure it.
Of course, everyone is not me, so we're forced to rely on the manufacturers rating.
Once we know what an injector flows at any pressure, we can calculate the flow accurately enough at any other pressure.
It's simply the flow at any one pressure multiplied by the square root of the pressure ratio.
Example.
Injector A is rated ( or measured ) at 10#/hr at 10 PSI.
We wish to use 20 PSI. The ratio 20/10 = 2. The square root of 2 is ( roughly ) 1.41. So, 10# times 1.41 = 14.1#/hr at 20 PSI. HELD OPEN, not cycling as it does in the real world.
Not too tough.

How much flow does this injector have at 5 PSI ?
Again, the ratio is 2, but we're going down, so we multiply by the inverse. ( divide )
10/1.41 = 7.09 or about 7.1#/hr

How much horsepower can this injector support ?
Depends on the brake specific fuel consumption of the engine.
Translated, less than you probably think.

Bottom line:
If your total VE range is somewhere between 5% and 99%, and your injector duty cycle is somewhere between 4% and 85% over the entire operating range, you're good to go. ( unless you're running nitros, or a blower, in which case you can exceed 100% VE )

 

Keep in mind the higher MAP areas of your VE table may in fact have lesser #'s than those around peak TQ RPM. Not sure why that is maybe CFlick can address. I had values way to high and my resulting PE commanded never matched my WB. So power was off. I recall pulling 10-15% out of VE there. Look at stock EBL bin or the one you chose to verify this.