camarorsssss

iTrader: (2)

So I have the EBL system and I have been attempting to get the AE down, but it seems to be proving somewhat difficult. Let me explain my problem and maybe someone has a solution. I have gotten good advice on here before in regards to tuning but i am not satisfied just yet. I have messed with all of the AE settings but it's still not right. The issue is that from a stop, if I slam the gas the car will either give a pop and want to stall or it will bog down and then after a few seconds get up and go. I realize that the symptoms are either from being too rich or too lean at wot. When I am cruising and I then slam the gas the car reacts as it should, it gets up and moves. I believe it has a lot to do with running a carb intake with the TBI setup because the manifold runners are larger and it sucks the fuel in quicker hence drying out and leaning out. It just seems impossible to get it just right where I can stomp the gas to wot and have it get up and move without hesitation. i was running 22 psi fuel pressure, but dropped it down to 18 because it was running rich and the problem was still there even with the higher pressure. Any help or insight is appreciated.

dimented24x7

iTrader: (2)

The AE is mainly a function of MAP and manifold temp. At low MAP, the fuel readily vaporizes. But when the MAP rises sharply, the fuel will no longer flash over to a vapor, and will settle out on the manifold floor if the manifold walls are cool enough.

What kind of manifold do you have? This can be a real issue with some of them as the manifold temp constantly changes, and changes the AE needed. When the engine is sitting in traffic, the manifold heats up, and little AE is needed. When your cruising, the fuel vaporization cools the manifold, and more AE will be needed for acceleration.

Do you have a wideband? Its almost impossible to nail the AE down without it. But, what you can do is take it to an open parking lot, and hit the gas from a standing start and watch the exhaust. If it pops out the intake a lot and the exhaust is slightly hazy, its lean and needs more AE. If it doesnt pop, but is sluggish and blows black smoke, it needs less AE.

dimented24x7

iTrader: (2)

FWIW, heres what the AE requirements look like when plotted against teh temperature of the manifold. This is a table from my old TBI code that had a temp sender installed in the manifold plenum wall just for AE. The higher the multiplier, the more AE was needed as the temprature changed. As you can see, it changes quite dramatically as teh manifold warms up.

camarorsssss

iTrader: (2)

It is an edelbrock performer intake. I do not have a wideband O2 set up, I guess i have been trying to put off getting one as long as i can but it looks like ill need to get it to figure this out. I have been struggling with this for almost 6 months, and I have gotten it to a point where it was real close, but if i make a small adjustment up or down in tps AE or AE v RPM i still either get the lean pop or the slightly sluggish bog. I cant seem to get it right on. The other thing i have noticed is that upon deccelerating if I give it a quick stab it sometime backfires on me as well, which to me would mean that something in decelleration I would need to be adjusted, but i think there are other settings I am missing. I feel like I am the only one struggling this much with a carb manifold with tbi and getting ae right.

RBob

iTrader: (1)

Double and triple check the fuel pressure. A quick check is to observe the gauge and whack the throttle wide open for but a moment (don't over-rev the engine).

When doing that the gauge shouldn't budge from the 18 psi. If it does then the fuel delivery is inadequate.

You shouldn't have any difficulty with AE using the performer intake. The runners aren't much larger then a stock intake.

RBob.

camarorsssss

iTrader: (2)

I can do that fuel pressre check with the car in park correct, or does there have to be a load on the motor to accurately check the fuel pressure?

RBob

iTrader: (1)

In park is correct. When the throttle gets whacked open there will be a short/sudden demand for fuel. It isn't as good as a full WOT run, but can easily show a deficiency in keeping up with demand.

RBob.

Ronny

iTrader: (1)

There is also a filter for AE-TPS and AE-MAP. The filter can affect the duration as well as volume of AE event. I found the RPM multiplier to be very helpfull. I ended up with a positive multiplier 400-1600 rpms and a neg mult above 1600 rpms. I also have a larger runner manifold than stock and larger injectors aswell.

camarorsssss

iTrader: (2)

ok my fuelling seems fine, no drop in pressure. as for my rpm muliplier here are the numbers i am running along with my other ae numbers, maybe someone can point me in the right direction.

alvanwie

I also had a lot of difficulty with my setup trying to get consistent results on accel under all conditions. Tried running mostly tps AE and tried MAP AE but there was always a hole somewhere. I am not using EBL. I was running standard 8746 code. I had to run lots of tps AE to get it to not go lean. The stock 8746 code gives basically a single shot of tps AE. I finally modified the stock code by adding a filter to the tps to make the AE last for a longer time. With this change I then lowered the tps AE a lot and all the inconsistency on accel went away.

I believe the EBL code already has a filter on tps for AE. Perhaps Rbob can advise you how to use it to increase the amount of time the tps AE will last.

Good luck
Al

RBob

iTrader: (1)

Noticed the XDF version. Set this parameter to 100%:

AE - >TPS% Double MAP AE

Otherwise it can drown the engine once the TPS% goes over whatever level it is set to.

As for the filters, the lower the value the longer the duration of AE. A side affect is that a lower value will also increase the volume of AE. So use the filters to control the duration and the PW tables to control the volume.

Trim for engine temperature using the CTS compensation table.

Trim for RPM using the RPM compensation table.

Another aspect of AE is the spark advance. Too little and that too will cause the intake to cough.

AE is also used to get to PE mode. Make sure that the PE in coming in soon enough, but not too soon.

Do all of the initial AE tuning with the engine up to operating temperature. Once set up then use the CTS compensation table for when the engine is still warming up. Note that you shouldn't beat on a cold engine.

RBob.

Ronny

iTrader: (1)

I had best results starting noticibly lean(intake pop) and working rich.

Your RPM mult is much like mine. your 18 lbs FP may help counteract the larger runners of the Performer intake.

Can you determine approx where you are seeing the issue based upon range of RPM-MAP and % of TPS. Reference the datalog and mark the event with space bar.

camarorsssss

iTrader: (2)

as soon as the snow melts away a little bit i will take the car out and do some test runs and datalog the runs to see where the issues are.

How do I know if the PE is coming in at the right time. right now i have it set at 60% tps above 4000rpm, 50% at 3200 and 40% the remainder of the table.

update today, i seem to be real close now with my wot from a stop, no more backfire. I do notive how ever that when i am cruising at say around 25mph and i stab the gas it hesitates for a second, almost like it drowning or missing for a second then it catches up and moves. Not sure what would cause this?

camarorsssss

iTrader: (2)

ttt

RBob

iTrader: (1)

Be sure to data log every drive as you sort this out. The EBL Analysis Dump log feature puts a ton of info in text or CSV format. Also, tap the space bar when something isn't quite right.

Or, tap it ahead of time when you are forcing an issue in driveability. This puts markers in the data stream that are shown in the various analysis displays.

I do notice how ever that when i am cruising at say around 25mph and i stab the gas it hesitates for a second

Check the data log and look at the O2 sensor value and the INTegrator value.

This area may need a tweak of the AE vs RPM table. Need to check a data log to see what is going on.

RBob.

camarorsssss

iTrader: (2)

can i get a look at someones open loop afr vs rpm vs vacuum, im down to trying to settle my open loop problem.

Ronny

iTrader: (1)

I dont think that table is your issue. I used the stock L03 table then enrichened it a tad (X .973) for my use. I am non emishions.

camarorsssss

iTrader: (2)

would a heated 02 sensor help out?

xch3no2

A heated o2 will typically allow closed loop operation @ lower engine temps if that is your desire.

One of the great benefits of heated o2's is their more stable or consistent readings, often used to overcome downstream/header mount locations.

A heated o2 sensor will have no affect on tailoring your Open Loop settings, other than the earlier exit from that mode.

dimented24x7

iTrader: (2)

Heated O2 wont really help. At best, the O2 readings will tell you if your richer than stoich, or leaner. You really should invest in a wideband for sorting out AE. Thats the one part of TBI tuning that can be a real nightmare to get right, depending on the setup. Without a wideband, you'll have some guesswork on trying to get the volume and duration right. Thats one of the reasons I no longer run wetflow systems.

Ronny

iTrader: (1)

When you patch in the WB data into WU datalog you will be able to see specifically the timing of the event(not spark). You will also see the quantity of event. You will see the duration of event. That will give you an handle as to which parameter to tune(filters, rpm specifics, tps%AE, etc). I think RBob now offers a WB upgrade in EBL. I use Innovate.

I have been working with AE for past two years in attempt to improve it and struggle with changing enviormental conditions day to day, season to season, or time of day. My AE tables just recently were changed so as to have 200% more AE in RPM modifier at lower RPMs 400-1800 as my velocity in intake tract I feel is compromising my AE. Especially if I need to lift off throttle aproaching a slow turn ay 5MPH from 40 MPH. All my wall wetting is pulled due to vac and velocity is low in intake. I have moderately large ruinners in intake as well as 180cc heads.

camarorsssss

iTrader: (2)

I thank everyone for their help and believe, at least for the time being that i have gotten my ae pretty close to perfect. I am sure it will need adjustment as the weather changes but I will tackle that when it comes up. My biggest issue now is my cold start open loop driveability. It feels like it is super rich and almost sounds like it is choking it self with fuel if i give it any more than 25% throttle but if i go slow and ease into the peddle it isnt as bad. Forget trying to merge onto a highway it doesnt have the power and barely moves with more throttle. but once the car warms up after 10 minutes it drives great. I messed with the Open loop afr vs vacuum vs rpm, but didnt help any. Does anyone have any insight into what it could be?

xch3no2

Two places you can make corrections in tables,

Choke-AFR, limited to choke operation parameters.
&
Open Loop-AFR Multiplier vs CTS, for effect including and after choke, until closed loop.

If it seems to be an AE issue then adjust,
AE-CTS Multiplier %

camarorsssss

iTrader: (2)

ok, for the afr mulitplier for cts, do i need to add or take away from the table?

xch3no2

-percentage is richer,

+percentage is leaner.

So to lean it, add positive.

camarorsssss

iTrader: (2)

ok great , i think that may be what i need to adjust to get it right.

DAVECS1

iTrader: (2)

I would not ignore your timing tables and timing vs temp correction array. THe symptoms you describe, sound much like mistimed maximum Brake torque angle. Not sure of your engine and head combo, but most street combiations should be tolerant of a wide band of fueling arrangements before producing an audible missfire. Unlesss the mixture is pre or post ignited by the ignition. In a transitional state such as acceleration it is critical that timing vs manifold vacuum be close as this value is based soley on table interpolation.

camarorsssss

iTrader: (2)

hmm another good point, i think once i try adjusting the openloop table and see if anything changes ill go back to timing. I could probably retard the timing a little im sure. i have some datalogging and work to do.

Ronny

iTrader: (1)

Is your BPC accurately calc'd? That will affect the OL resulting A/f ratio if off. Likewise crank and choke. there is a filter to time out choke if that is a contributor to richness.
Post cid... inj size... and FP and I can calc and compare to what you have.

camarorsssss

iTrader: (2)

305 with 61# injectors at 18lbs of fp. My bpc is 101. I have attached my choke and crake afr numbers.

xch3no2

One other thing not yet mentioned is that actual AE delivery is pressure/flow dependent, and not affected by BPC settings.

So when fuel pressure is raised, or injector size increased, AE PW should be adjusted to compensate.
Info on how to adjust is here in AE/injector flow notes http://www.dynamicefi.com/Tune_Intro2.php

Ronny

iTrader: (1)

My calculator shows 122.5 ?

Are those choke crank tables stock from EBL.bin? 305 cid auto trans.

camarorsssss

iTrader: (2)

really, the program i got from to calculate bpc using those numbersrnumbers gave me 101 bpc. I can try your numbers and see if it helps.

Those are the stock numbers , as far as i know, for the 305 stock bin. do they not look right?

Ronny

iTrader: (1)

This is my program given to me by another TGO member.
Is there an error in input data?
Injector Sizing Calculator


Standard Injector Flowrate 61 Lb/hr
@ 18 psi Results
No. of injectors 2 These injectors @ 18psi
Injector Duty Cycle% 80 Will flow 61 Lb/hr
BSFC 0.45 And support approx 217hp

New Pressure 18



Only Insert Data in the BLUE Cells !!!


BPW Calculation: ('7747ECM)

Bore: 3.74 In
Stroke: 3.48 In
Cylinders: 8
Capacity: 305.00 Cubic Inches
5.00 Litres
Injector size: 61 Lb/Hr/Injector
7.453121697 grams/sec

BPW: 122.5095411

RBob

iTrader: (1)

The BPC of 101 is correct.

BPC = 1461.5 * (CylVol/FlowRate)

61#/hr injectors at 18 psi is:

sqrt(18 / 13) * 61 = 71.7 #/hr = 9.0 gms/sec (#/hr * 453.6 / 3600 = gms/sec)

5.0l / 8 = .625 l/cylinder

Then the BPC calculation:

1461.5 * (.625 / 9.0) = 101.49

Apparently there are some incorrect BPC calculators roaming around. Ron, you should have the one that is supplied with the EBL. It was later changed from a Excel SS to a Windows program.

RBob.

Ronny

iTrader: (1)

I will look on laptop this evening. Whatever is on the CD should be present. I do not recall seeing it however. I believe I have an early release of EBL. Did the early ones also include it? I also dont recall seeing the BPC vs VAC calculator I have heard of as well? I was going to rent a MightyVac or borrow at AutoZone to do the measurement but never got around to it last summer. I am using a calculator again provided by a member here for BPC/VAC.

Ronny

iTrader: (1)

what is significance of the factor 1461.5 ??

RBob

iTrader: (1)

It takes into account the injector firing rate, the number of injectors, and Boyles gas law.

RBob.

camarorsssss

iTrader: (2)

interesting, i didnt really know how the calculator came up with its number. I did make an adjustment to my sa initial timing. It was set at 5 degrees but my distributor is set at 0, so i set it back to 0.

Are my numbers in my crank and choke afr tables normal or could there be changes made there?

Ronny

iTrader: (1)

If they are stock 305 values then with large injectors and 18 lbs fuel pressure most likely you have more fuel than you need. Unless you have a VAFPR. Every one that runs one says it improves drivability. check EBay on VAFPR.

On cold start I begin at 11.0/1 and it moves to 12.5/1 ay 145dF.

xch3no2

! I think I see your calc prob Ron, BPW cannot be used for the BPC setting.

Ronny

iTrader: (1)

Of what value is then knowning the BPW?

I understand "pulse width".

I thought BPW = BPC. Apparently I am wrong. I believe some mask's use BPW and others dont per my search. BPC is shown in RBobs formula and that I used to manually calc constant when I first needed to years back.

I have another calculator for BPC/VAC and that one matches up the manual calculation and is one I am using in my bin.

camarorsssss

iTrader: (2)

Is that for my crank afr or choke afr or both?

Ronny

iTrader: (1)

Both.

I lose a lot of fuel in cool weather on startup. I need to let car warm up in driveway. Summer I can drive immediately. Cold start I am at about 12 lbs FP with my 80 lbs injectors with a 350. stock tables from a 305 for crank and choke. I would be fearfull of fouling plugs with your FP and larger injectors. I would error on safe side.

camarorsssss

iTrader: (2)

ok will do. one more question in making the adjustments to the tables, do i need to add to the numbers or take away, i am not sure exactly how those tables work. I know it is rich upon first start up, i too have to let it idle for 5-10 minutes before driving.

xch3no2

Cranking-AFR # is the commanded AFR so larger # are leaner.
Note EBL code is different from stock, (1/2 injector firings), so AFR's used may seem rich comparatively.

Choke-AFR # is AFR points subtracted from OL AFR so larger # are richer.