IIRC, the ZT-2 output is non-programmable. It is a curved line. Which is set up in the WUD as a built in device. Uses a look up table.

RBob.

 

You can also use the WUD for timing acceleration runs. The HP & TQ figures are most likely rear wheel, not flywheel. Not sure how much faith I put in a g-tech anyway.

One item that is important is which ICM is in the distributor. Best bet is to get a GM unit with the number 369 on it. This is found on the top of the ICM. The reason is latency in the module. Using a 369 module will ensure that the spark timing is correct.

RBob.

 

I will double check my ICM, but if I am not mistaken it is the GM version. I just find it hard to believe with all my mods that i am getting less horsepower than a stock tbi. I am going to use the WUD to track acceleration.

 

IIRC, the stock L03 was only 160 HP at the flywheel. If you can find a flat level safe area, do a 1/4 mile run. Then check it in the WUD. The stock L03 f-body is in the high 16 second area.

RBob.

 

How do i calculate injector flow scalar. I have 65lb injectors but I want to up my pressure to around 18.

 

I believe at the time of purchase the included utility was an Excel SS. The releases from near the beginning of this year included a Wndows EBL Utility program to do the calculations. Email me if you want the EBL Utility program.

RBob.

 

This has been sent.

RBob.

 

I still cant get my WB readings right. Looking at the WUD and looking at my gauge gives me 2 different readings sometimes. Like the gauge will read 15.8 and the WUD is saying 14.8. I want to play with some more learns now that the weather has changed but I don't want it to be all screwed up. How do I calibrate these two?

 

IIRC, you are using the ZT-2? And you mention that sometimes the two give different readings. If this a built in ZT-2 gauge, or an external gauge?

Not a lot to go on here. You may have an issue with ground offsets, or the filters don't match.

RBob.

 

it's the gauge that came with the unit. I bought the whole set up from Zeitronix. i know before the update the WUD and the gauge were spot on, now it's definately off. I know the WB is tied into the "0" port in the EBL. When going through the filters do I just adjust it till it's right?

 

Robert

I have ZT2 with my EBL setup and have been wondering about this discrepancy for a while until I did some comparisons and observation. What I think is going on is that display has its own averaging data algorithm so that the ZT-2 displayed data appears to be different from what is being captured by EBL analog port. Under steady state OL condition O2 values tend to stay nearly constant - (Highway mode) with both ZT-2 display and EBL displaying the same values. It is kinda dangerous to perform the same display comparison in PE mode! The moment I drop into CL wherein AFR varies the two instantaneous values (display and EBL) diverge.

//RF

 

I don't know........ It's actually starting to drive me crazy. I want my readings to be right again. I have been playing with my VE tables manually to try to get it right but it's kind of hard to go by 2 different readings. The WUD says everything is beautiful but my ZT-2 gauge is telling me she's going lean. So to get things right would be awesome.

 

The only thing I can think of is the filtering for the ADC Channels in the WUD. For the ZT-2, set it to 0% (fast). The filtering is the only real change to the WUD in this regard. None of the WB tables or routines were changed.

RBob.

 

one thing I didnt think about is that there are 2 settings in the ADC channels for a Zeitronix WB. One Non linear and the other has voltage numbers next to it. I have it set to the latter selection. Should I set it to the non linear Zeitronix WB setting to see if it makes a differance?

 

Yes, try it. The linear selection is for when the simulated NB O2 output is being used.

The non-linear selection is for the standard WB output.

RBob.

 

ok switching it to the non linear setting cured the issue. It only seems to be off .1-.3 percent on occasion but nothing serious. Thanx for the help

 

Can someone explain the AFR vs RPM & VAC table to me? It seems like it is backwards. At 2000 rpm and 80 kpa, commanded AFR is 14.7. while 2000 rpm at 40-60 kpa where i am cruising on the highway, it is calling for 13.8 to 14.0

Wouldn't I want the rich condition during high kpa, and the 14.7 at about 40-60 kpa where you can save gas while cruising? __________________

 

The table load axis is based on intake manifold vacuum. That is 80 KPa is low load. And 0 KPa is WOT.

RBob.

 

BuckLee: That table is for open loop operation. Engine runs off that table before coolant is sufficiently warmed to allow closed loop. I believe it is also looked at with modifiers for crank and choke during start and shortly thereafter. I idle OL so I tend to look at that area where I idle in. I have made small changes in that cell. I seldom see higher RPM and low VAC cells in daily driving.

 

Is the table used during a learn VE? For ex. the computer records the afr for certain kpa and rpm, compaires it to what is in the rpm vs vac vs afr table for same kpa and rpm, then adjusts it to become closer to what is in the table in the new bin?

If not, what does the Learn VE Make its adjustments off of?

 

When using the WB based VE Learn with the ECM in open loop, yes, that table is used. Although it is the commanded AFR that is compared to the WB reported AFR. This commanded AFR is from the mentioned table, plus/minus any modifications, such as CTS compensation.

Then while in lean cruise mode, or PE mode, there is a table of commanded AFR values for each of those modes.

RBob.

 

in closed loop, that would be the VE table. i guess that's what you were looking for?

 

Just to be sure that we are on the same page (together, or correct about this). The VE table is always in use. What changes is the commanded AFR. That in itself will change the calculated injector PW.

The basic PW calculation is: PW = ~AFR * ~T * VE * MAP * BPC * BLM +- CLT

~AFR = inverse air fuel ratio
~T = inverse coolant temperature (or CTS/IAT term)
CLT = INT and proportional gains together = closed loop term

RBob.

 

I have recently purchased the EBL Flash for my 91' chevy truck. Thanks Rbob! I havent torn into it just yet but im just briefing myself on some important things and reading as much as I can before i do the install. Anyone have any insight as to what i should look into or any tips while i get started. I have a mild 212 219 .449 .456 112las cam with all the tbi mods edelbrock 3704 intake, dual exhaust, headers and pretty much all the bolt on stuff. Also, how do you change the BPC and go into lean cruise. I havent plugged everything up so does that start when i plug into the truck? Thanks guys

 

Calibration info is critical. Esp w/mods. Take your time to understand & set each one that pertains to your set up.

I tried to rush installation in a January monsoon.. bad idea.

Intro to tuning @ RBob's site is REQUIRED study & application.
My application is not typical (but perfect) for the EBL, it is necessary.

As one example I had to crush AE-PW and reset RPM invoked, while having enough fuel pressure to supply upper RPM tables & PE
No VAFPR just yet.

Save & clean up your edit logs for reference.

30 setting changes is normal.
I have 80 or more to dial.
And the XDF remains unchanged.

Great work RBob!

 

Bucklee: Some use NB 02 sensor feedback to achieve closed loop fueling corrections. That would be me. Others use WB in place of NB to simulate NB output to ECU in OL. It uses that AFR/RPM/VAC table as Rbob stated. Third option is my first example and having the analog output from WB controller show the WB reported values in WU logs with no WB corrections taking place.

 

I will additionally repeat;

The boss said,

Start slow & steady w/throttle for VE learn, always steady, let it learn.
I prefer at least a slight grade.
NB is great for this.

Do it again.

I'm the bonehead who hand-smooths..
do it again.
End result, amazing accuracy to target o2 & AFR.

You will love that thing,

Your girl & friends are gonna get jealous of your time & interest.

 

You don't have to drive at all for some initial checks,
warm it up in the driveway, start learning & logging.

Slow & steady raise rpm's, watch "corrections" VE screen.
Fill as many cells as you can, then start a new learn, from the new bin.

Do power-brake learns for load as you are comfortable,
don't crash or burn up the tranz.

 

I have done 50-60 velearns and my engine runs ok but it feels like it has a lot of cam and it hesitates everytime I stand still with gear in and push the padal to get going. If I press down the pedal very very soft its ok but if I press it down normal it hesitates and I must pump a few times to keep it alive then its ok. At 50-65mph it doesnt run smooth it jumps forward a little. I doesnt have the skill to read the files to see if something isnt right, can anybody be so kind to help me with that? I have attached logfiles from idle, idle with gear, cruising and finally WOT and my binfile. I would be very happy if some1 could point me in the right direction what to change.
My setup:
Chevy 383
Afr 195cc (1040)
Compcams 280XFI
HSR 30lb inj.
Hawks Longtubes 1-3/4
EBL ECM
Comp 10,5:1

 

When you pull out from a stop, the O2 shows the AFR going rich. If so the engine will bog down. If that is what is occurring reduce the AE. reduce these two tables:

AE - MAP PW
AE - TPS PW

Can highlight all entries and multiply them using the tool box. Try a 20% decrease for the first reduction (multiply by .8). Then see how it is.

If you get popping out the TB, then it is too lean.

The other area that may be contributing to the excessive richness is the VE tables. They slope sharply upward as they approach 90 KPa. This is most likely from not having a WB to do auto VE Learns at WOT. The ECM goes open loop during this time and a BLM VE Learn won't be done.

In this case you will need to reduce the values manually. Just do a little at a time, and stay on the safe side of rich.

For the cruising, I didn't see an area at 50-65 MPH. If you could post a data log that would be helpful. Also, you can place markers in the data stream by pressing the space bar while logging. They will be shown in green in the analysis display.


The other thing is the O2 sensor signal. It appears to be noisy, something about it just doesn't look quite right. Check the sensor wire and EFI harness location. Make sure that it isn't close to any spark plug wires or near the blower fan motor.

RBob.

 

Most likely it is AE related. One way to determine AE correction is look at how/if the INT changes during thqat event you describle. If INT rises during event it is adding fuel and you may benefit from more AE. If INTfalls it is pulling fuel as AE fueling excessive. Of course a WB is a valuable aid as well.

 

New question;
Is the crank-PW multiplier calculation BPC inclusive?
Or strictly PW based?

Yes, this question came to mind when I tried to run the VE table TOO low,
since corrected, just curious.

 

With one exception, the cranking PW is the same calculation as used with a running engine. The exception being the cranking PW multiplier table. This table is typically used to provide some additional early cranking fuel, then to taper off the fuel (via PW), as the engine catches and comes up to speed. At which time the fueling reverts to running status.

Other then this PW multiplier table the biggest difference between cranking and running is the commanded AFR. There is a separate tables of AFR values for cranking (good 'n rich).

RBob.

 

Perfect answer, much clearer than the question,
I'm glad you understand.

I fattened crank afr & slowed PW-multiplier (decay) slightly in the middle after finding the bottom of the VE table.

FP @ solid 34psi, BPC @ 84, VE tables 25-98 to 4400 & fuel is still climbing under load.
watching DC..

Need track time..or a dyno..

 

Fired up my 383TBI last weekend, but could not get any tuning done due to leaky radiator. With new radiator in place I was able to get a better handle on things today. Engine is mounted on the engine test stand as I am trying to get as many basic tune issues out before it gets dropped between the two fenders.

About the engine:
383 with (+030 over) with 6" rods, 9.5:1 CR
trick flow Super 23 180 heads
Cam 8-304-08 210/220 .500/.510 LSA 112
Reworked BBC TBI with 85 LB injectors
Aeromotive 13301 VFPR

Engine Test stand


Intake top view


Back of the engine stand


Note use of mini bungees to keep ECM in place


Fuel pump can deliver up to 50 PSI, with VFPR has been set to about 17 PSI at idle (40-45 kPA). The problem at this stage (very early tuning stage ):

IAC is at 0 counts (reset couple of times to make sure) with idle bouncing around 650 - 775 in close loop (3-wire O2). Initial VE tables were way too rich (expected). Idle SA around 18-20 deg commanded (and observed with timing light). Commanded idle speed 625 RPM (probably too low) for this cam.

Question
How to tame idle -

1) disable VFPR and run constant fuel pressure for now (constant BPC vs. VAC table)?
2) increase commanded idle speed? up to 700RPM (minimum idle screw is fully back out)
3) bump up idle SA above 20deg?

//RF

 

750 is probably a good idle speed with that cam.

Reduce the idle compensation Sa

Rework the idle VE table a little. Make sure that it doesn't get lean in any areas.

Try open loop idle to see if the closed loop prop gains are too high.


RBob.

 

Rbob

Thanks for the tip - I've increased target idle RPM from 625 to 750 RPM, and reduced idle SA compensation tables:
SA - Idle High Compensation
SA - Idle Low Compensation
SA - Idle high MAP multiplier (brought 45 and 50 kPa values up 10%)
SA - Idle low MAP multiplier (brought 45 and 50 kPa values down 10%)

I left proportional Gain tables (PRP - Gain vs. O2 error) as they are for now.

As a result of above changes engine is idling smoothly in 725-750 range, in a close loop. IAC counts are around 30-39 range which is also reasonable.

VE tables got a bit of cleaning - with pair of 85 lb and FP at 15-16 PSI my VE tables in the idle area are in 35 to 40%. Injector pulse width is around 1.2 mSec (DC 3%). VFPR seems to adjust FP, but not where I need - at idle it should drop FP down to about 13 PSI vs. 16PSI - will have to investigate this. Thank you for the help.

//RF

 

Open the throttle blades a little for an IAC count of 5 - 10 when warmed up. That too helps with the idle and off-idle response.

RBob.

 

A quick update here.

Aeromotive 13301 spring (0 to 20 PSI) has a dynamic FP adjustment range of about 12 PSI - in other words from 22 PSI with no vacuum down to about 10 PSI at idle vacuum (on my engine it is about 16 in-Hg. The problem at this time is slightly surging idle (VE tables are not dialed in yet) and this variation in idle vacuum causing BPC variation. So, for now I plan to go with fixed FP at about 16 to 17 PSI to dial initial low speed VE table values and eliminate rolling idle before venturing into VFPR configuration. Got to do this slow - step by step.

With FP set at 16 PSI my commanded injector pulse width is about 1.2 to 1.4 mSec at idle (750 RPM) - the question is it reasonable pulse width for 85 lb-hr injectors?? Hopefully not too short.

Commanded SA at idle is about 18 to 20 deg - I wonder if it is enough for this engine. What is the best way to dial in SA for better idle??? Any feedback on TrickFlow Super 23 195 on 383??

Had couple of minor scares - both fuel pressure gauges reporting 16-17 PSI yet injectors are not spaying. Swapped ignition modules as a precaution (WUD was reporting pulses during cranking so that was not it). Kicked myself earlier this morning - gas tank was bone dry! After adding some go-go juice and with engine running alternator light came on. What is it now?! - Loose nut on alternator BAT stud terminal - gotcha! What I thought was a front oil pan leak end up being a minor coolant leak from water pump by-pass port. Fun- Fun.
Engine is mounted on the test stand so it easy to see and get to offending areas...

//RF

 

I run same reg and same spring(weaker). My observations are same as yours on VAFPR. I run 80 lbs injectors at 20 lbs pulled down to about 11 lbs. The stiff spring at 20 drops pressure to about 14 lbs at idle I recall. Only diff is my PW is about 1.8-1.9 at 800 rpms.

SA idle for me is 17. And the option flag for that is set.

I disabled asynch so at idle it wont allow asynch. Are you same here? Maybe that explains my higher PW. Previously when asynch the fueling would move in logs and idle pulses.

I set the OL A/F tables so all surrounding cells are same @ 13.8/1. should idle wander fuel will be same and spark is locked. PW moves up down from 1.8 to 1.9. IAC counts stable at 10.

I idle at 13.8/1 A/F on WB. And OL flag is set.

My idle still pulsates but not too bad. I think my commanded RPMs in park/drive and neutral(I have manual trans) are lower than 800 so I am sitting on throttle stop screw. TSS is very touchy if I move it a tiny bit I will idle too high. 7.4L TBI.

 

I have couple house keeping questions...

1) What is maximum length of RJ9 cable can be used between ECM and lappy? I need to have my lappy of to the side ~ 6 to 10 feet away from ECM. I assume that all 4 pins must be wired...

2) IAT - my current harness has no provision of IAT (will take care of that later). I've disabled IAT with Malf Flags IAT23 & IAT25 by setting bit to disable (checked). However, do I have to alter any IAT/CTS blend tables (SA, Blender filter table is set to 100% of CTS) ??

//RF

 

RF,
1) I have been able to use 20' with no problems.

2) Per calibration info that's all it takes (100% CTS).

 

Thanks for tip - I'll try longer cable during week. CTS/IAT Table - it is self explanatory.

Completed a short tuning session late on Sunday - found that with higher FP (set at fixed 16PSI, no VAFPR) I flood during cold start. This was to be expected since low speed VE tables were not close. Warm restarts appear to be problem free, but with CTS at 22C my cranking sPW were around 17.4 ms (commanded AFR 4.3 per Crank - AFR table).

I did a thread search and in post #441 it was mentioned that:
The VE table is always being used. Crank, warmup, WOT/PE, lean cruise, the VE table is in use. The other modes, such as WOT, and lean cruise, open loop, cranking, just command a different AFR. And are still using the VE table.

So if I understand this correctly injector pulsewidth is based on low speed VE tables, except that commanded cranking AFR is calculated from VE values in 400 RPM row (by applying Crank - AFR table multiplier)???? e.g. if I drop VE values in 400 RPM row this should solve my cold flooding???

//RF

 

Cranking typically uses the 400 RPM, 80 - 100 KPa area of the VE table. Can reduce this area to reduce the fuel during cranking. Can also change the cranking AFR table to reduce the fuel during cranking.

On some stick shift vehicles, or if the engine is stalling, then this same area of the VE table is in use. So it is best to have that area of the VE proper for a warmed up engine. Then change the cranking AFR for the best start ups.

RBob.

 

Thanks Bob - that's what I am going to change for my next tuning session. With engine sitting on the engine stand I can only hit a limited number of cells! Original VE table had values in 85 at 400RPM, 100 kPa so I'll drop them 10 to 12 points and see how it cold starts - 22C (75F) in SoCal is a cold start.

//RF

 

IAT use was a real bonus for me. In wisconsin spring-fall I would see underhood temps with coolant at 185F sometimes 75-85 d F.

Question: This spring I saw BLMs 130-140. Rather than mess with VE should I not have changed the IAT/coolant tables to account for high BLM? I think I ended up doing that. I Need to compare old bins to current.

 

RF,
I assume you did reset BPC vs VAC for the steady fuel pressure?

 

Yes, it was the first thing that I have edited in my bin file. I know it is step back but I was fighting too many variables at the same time and VE's being way out there is no clear way of isolating main factors. The idle now is steady (I would not call it smooth) in close loop.

See for yourself (after switching to constant FP)

http://www.youtube.com/watch?v=vtGR8VKzW-c

//RF

 

Cool video. It looked like there was a flex plate on the back of the engine. Once some weight is added, torque converter or flywheel/clutch, the idle will be smoother. You will also need to add some additional AE once the engine is in a vehicle.

For a vehicle, an early 2nd gen Camaro or Firebird is a good choice. Mostly from an emissions view.

RBob.

 

ok guys, been chasing tail it seems, can't get my interstate cruise going, will try to post a log. Can someone lead me in the right direction. Disregard, can't get attachment to upload, will try later