The BLM going to 128 on a rev is normal. That is a different BLM cell and hasn't been learned in yet. Just wanted to mention this so that it isn't a mystery.

nintyone is having somewhat of the same issue:

thirdgen.org/techboard/diy-prom/645211-rich-vacuum-leak.html

He needed to reduce the VE table by 10 to 20 %.

I've thought of a couple of items that may be causing it. The vapor purge system is one (CCP). Although it shouldn't be active at idle it may not be operating properly. Sitting all Winter the canister would have quite a bit of fuel in it.

It may be purging which will cause the INT/BLMs to drop.

Another one is interesting, was the car being run in the garage? Or in an area where the exhaust may be getting fed back into the engine? Less O2 in the air will cause the INT/BLM to drop.

Is there EGR on the engine? Maybe it is leaking exhaust into the intake.

Maybe the fuel composition changed while the car was sitting.

RBob.

 

I've attached 2 short datalogs.
1 is while in Park n idle
2 is a short drive.

Any insight would be much appreciated.
thanks

 

Haven't been able to catch this in a datalog yet, but as soon as I touch the throttle from an idle in drive, my WB dips down to 10:1 and she bogs way down for just an instant. This can be reproduced without invoking AE (I believe, I want to log it to be sure). If not AE, what could the cause be? I saw a thread where the guy ended up lowering the AE threshhold and then using the lowest AE setting to pull fuel. I'm gonna try this as soon as my laptop battery is charged again.


Also, concerning WOT VE learns via WB, does PE need to be disabled? What I find as I'm at WOT, the position in the VE table is jumping around too much for the box to turn green I think. The middle and upper VE tables are hard to get steady without a mountain road handy!

 

Compared to the factory 7747 I was using before, the EBL doesn't seem to do really any fast idling at startup. I think the factory setup did too much, but maybe it's too little now, like it fires up and then idles rough for a while around maybe 700 RPM or less before workings its way even lower. I know there is a table of idle speed vs. temp, is that what I should work on, or is there also some sort of timed high idle on startup?

 

The too rich sounds like it is the VE table. Although you didn't mention whether this is at operating temperature or when cold. If when cold it may also be the afterstart enrichment or the open loop AFR vs CTS compensation.

Leave the ECM in PE mode when doing WOT VE Learns. I've run into the same thing with the RPM climbing too quickly to get a good learn during WOT. Making sure to start out on the rich side and using a higher gear helps.

RBob.

 

Make sure that on a warmed up engine and no other loads on it that the IAC steps are between 5 and 10. Adjust the idle stop screw to get these steps.

Can increase the idle RPM via the IAC idle speed tables. There is one for in P/N and another for in drive.

The roughness may be from it being a bit on the rich side.

RBob.

 

Thanks, I'll check the IAC level. I have no P/N, so I'm always in drive. Maybe that's part of it too. The idle BLM was actually pretty good (~130), but it also smooths out as it warms up and goes closed loop, so I don't know what it was doing before that. Is there value in pushing down the closed loop temp threshold if I have a heated O2?

 

Depends if the engine likes it or not. I tuned one set up that I needed to raise the CTS threshold to go into closed loop. Prior, for about a minute after it went closed loop the engine just didn't run right.

So raised the CTS threshold for closed loop a couple of degrees to hold it off for another minute.

RBob.

 

Had some strange behavior around idle today. I didn't notice anything performance wise, but watching the display while idling the BLM values started ramping up and hit 172, which I assume is the max. Previously it has been happy at idle. I had it in learn mode and while driving around it was filling in with small values, like plus or minus 2-3 in correction in non-idle areas. Around idle (low RPM, low MAP) the values shoot up to 12. I could lightly feather the throttle at idle and see the BLM jump abruptly from 128 to 172.

One theory is that maybe it went closed loop before the O2 was ready, got a bad BLM value in that idle area, and then it sort of stuck and I saw the big BLM on the display any time it crossed into that BLM range. ?

I think I don't understand how the system works with respect to learning around idle. It looked to me like, even though it said it was in closed loop, it often sticks with a certain value without updating. Is there some sort of lockout?

On one occasion I also noticed it drop out of closed loop at idle. Revving the engine got it to snap back in. Does that indicate an issue with the O2? It doesn't quite make sense because after revving it and getting it back in, it seemed like it would be happy forever. I have a heated O2 also.

Thanks for any help.

 

This all points to an O2 sensor that is cooling off.

RBob.

 

Can you think of a reason why it would appear to me from the WUD that the BLM values were not updating even though it was in closed loop? Maybe it's related to learn vs. closed loop. I don't think I understand what the "learn" indicator is telling me, can you explain?

I was poking around the bin and found the table called (at work now, going off of memory) closed loop TPS thresholds or something like that. It has two values in it. If I'm understanding right, I think it would go out of closed loop with TPS below about 1.5%. Is that right? If so, I'm confused how the BLM values could have been changing on me at idle since my TPS goes to 0% when my foot is off. Any ideas?

Sorry for the question bombardment, but if I do have a cooling O2 problem, what can I do, either programming or hardware wise? I already have a 3-wire heated O2. If it cools off at idle irrespective of coolant temp, going off of CTS obviously won't help. In this case it was during warm up I think, but historically I've had high BLM at idle all the time. When I first fired up the EBL it was acting great at idle in closed loop, so I thought I was out of the woods.

 

I believe that is to allow OL for idle under that threshold. If you check the OL-ILDE flag it will idle OL. But the BLM value I believe then locks at whatever value was last seen.

Maybe NB02 sensor is reflecting lack of grams/sec that may be occurring. Just a wild guess. Is you heated NB correctly wired?

 

Is there a difference between open loop idle and plain old open loop? I think I may be missing a subtlety here. The WUD indicates closed loop even when the TPS is 0%. Maybe there is a timer or filter that keeps it closed loop for a little while or something?

 

It is just that EBL.xdf allows OL idle for a car that needs it due to cam overlap. Actuaully you can run OL up to say 15 mph if you like. I beleive you can hold OL further than <1% TPS as well.

I had a header collector leak once that caused BLM to rise to big numbers?

 

Closed loop enables the INTegrator to move along with having proportional gains active. These force the AFR to oscillate.

When learn is enabled the BLM is allowed to move. Learn can be disabled for various reasons, low or high RPM, or a low or high MAP can do it. These are calibration parameters, so will also vary in thresholds.

The BLM follows the INT. Once the INT is so far from 128, the BLM will then move. But, the ECM also needs to see that this is required.

If the AFR is lean, and the INT is less then 128, the BLM won't follow. As the INT will need to increase first to bring the AFR richer. There are timers for much of this stuff too.

The INT and BLM will only be updated at certain intervals.

There aren't any closed loop TPS% thresholds. Although the closed throttle TPS% thresholds come into play if the forced open loop idle is selected. The TPS% thresholds are also used to define which BLM cell to use.

O2 sensor cooling off: maybe the heater is open. Or that the voltage to the sensor heater is being turned off.

RBob.

 

Did you see it mostly at idle, or across the board? My O2 is before the collector. It actually only reads two cylinders on one side. My headers are emission style though, with ports for AIR, which I have plugged. I noticed the plugs are not sealed very tight - kinda loose with crusted old sealant. I wonder if that could be enough to cause trouble. I resealed them with copper RTV just now...

 

My VE tables are at 100 % in some areas, so I need to increase cylinder volume by a little bit to allow more headroom, correct?

After that, is there an easy way to adjust the ve tables all at once? what percentage multiplier should I use per given increase in displacement value?

 

I'd actually do a couple of things.

1. Increase Injector Bias especially if u are getting sort of a bathtub pattern in the VE table.

2. If that doesn't help w Inj. Duty Cycle and VE, increase fuel pressure. You'll need to change the Base PW constant. It also may affect idle if you can't get PW low enough to control idle. This is why I loved what RBob did with the variable BPW table for using a VAFPR. Worked great in my 84 Xfire.

 

Not quite sure whose confused here lol (although its probably me with my unfamiliarity with the terms you mention). As far as I understand it, 100% Ve just happens sometimes, and in EBL, all you have to do is increase the BPW a little bit to allow a little more headroom. In the P4 flash, there is now BPW, so can either increase injector constant or cylinder volume, and then relearn VE. But I was wondering what the correlation was between BPW and VE %.


I have plenty of injector, so I don't see the need to increase fuel pressure or fight idle problems.

 

100% VE says your out of injector. That doesn't mean you don't have enough injector per se, just that it's pretty much opened as long as possible and can't supply enough fuel given current parameters. I know EBL will show you Inj. Duty Cycle ( another great piece of info for tuning). I suspect your DC is up there in the areas of 100% VE. They may be going static. I suggested increasing the Inj. Bias first. The analogy to Inj. Bias is like timing advance for Spark Advance. The Injector opening occurs sooner so more of the injector pulse width is spent actually delivering fuel and not just opening. BPC stays the same but
"effective" PW increases. Therefore, you can reduce the VE necessary.

 

Note: slight edit on the above (BPW changed to BPC and to PW)

To reduce the VE table the injector flow rate needs to be reduced, or the cylinder volume increased. The lower flow rate would have the injector open longer for the same amount of fuel.

The VE% is a multiplier to the PW calculation. So it should be a straight percentage change to the VE table to lower the injector PW back to the original value.

RBob.

 

Is this really true? I've heard this a lot but can't make sense of it. I thought 100% VE means that the engine is working 100% efficiently, like 100% of the theoretical volume of air passing through the cylinders requires matching fuel to reach the desired AFR. I'm sure I got that a little wrong, but I think it is a function of the physical specifications of the engine. The injector comes into play only because VE is being inferred from what you told the computer about flow rate. I think VE should always be the same as long as you tell the computer the true flow rate, regardless of what it is.

Certainly it would be possible to hit 100% VE at low RPM without being out of injector, right?

 

So I should drop the flow rate by a percentage, and then drop my ve tables by that same percentage? I realize I'm making this more difficult than it should be lol.

 

Another question in my quest for understanding: under what circumstances will I be in closed loop with learn and not see the VE table updating in the WUD? This happened last night while I was trying to tune. I waited for it to go closed in learn, then switched over to the VE display (learn was enabled in WUD) and it would not ever "go green". And it really looked to me like it was dwelling in certain cells for plenty of time. I finally just drove off and it eventually started filling stuff in. Thanks.

 

When the "Learn" flag in the WUD is active, it means the BLM's can be updated, not that VE learning is active. If VE learning is on, you will probably see the VE table updating some time after the "Learn" light has come on. (Provided, of course, you are using the BLM's for VE learns.)

 

Is there any way to know that VE learning is trying, besides just watching the VE table to see if it's filling in numbers? Any idea what extra conditions must be met for VE learning to start? Thanks.

 

Still assuming you are working with BLM VE learns, you will need to be in closed loop with EGR and CCP disabled, and within the temp range described in the preferences dialog box. Might also have to keep lean cruise disabled as well.
Just make sure coolant temp is set to be in your normal operating range if you've changed thermostats or something. AFAIK that's it.

 

Yeah, I'm using BLM. I bet it was the temp range in the WUD setup. I didn't catch that, thanks.

 

Think you got that right there, in engine building/simulation/etc VE refers to the physical quantity of an engine's ability to fill its available cylinder volumes, i.e. 100% in a 350 would imho mean it's taking in 5.7l of air or whatever mass of air that relates to. This is different for each set of RPM, TPS% and probably MAP (load), but is imho rather unlikely to reach 100% or close, with a naturally aspirated engine safe for some very peaky racing applications.
In tuning, VE relates to the same quantity but the dimension is different, and as you said just based on the injector flow rate, so as it seems to me that's also why you can tweak the VE when messing with fuel pressure, injector flow rate etc without altering the engine, meaning its physical VE has not changed.
Hoping i got that right there but i know some of the usual subscribers of this thread are capable enough to correct me if that should be necessary

 

Quote:
Originally Posted by Ronny
I had a header collector leak once that caused BLM to rise to big numbers?

All areas/cells of VE table I happened to be in saw high BLM. Resulted in VE% over 100 in those areas that happened to be >80 lets say to begin with.

 

One of the "tells" re: an air or vacuum leak is seeing EBL continuously adding fuel(max 12%) in the low MAP/low RPM sector. I fixed an exhaust leak and that immediately reversed the fueling issue.

 

Any idea how much exhaust leak it takes? I have little plugs where my air pump lines used to go. They were not sealing very well, but it sure doesn't seem like much could get in there. And most times you'd think it would be exhaust going out... but then, with the tri-y headers there is supposed to be scavenging going on which might be sucking in, especially at low RPM.

Vacuum leak is a totally different animal I think. The ECM can properly compensate for extra intake air with more fuel. It's just like having extra throttle.

 

Quick question. Will the ebl control a 99 vortec 4.3 distributor? I have an ebl that im.pulling off a buick v8 and putting on a vortec 4.3 with a 4bbl intake. Need to know if i can jse the vortec distributor or have to get a tbi distributor.

 

You'll need a TBI distributor.

 

Dom said: That makes sense to me anyway due to the higher VAC present pulling in fresh air to NB sensor. My NB was right at the collector flange connection to ext pipe.

 

From my understanding the Vortec engines use an ignition control module (ICM) that doesn't have an EST/BYPASS line. They also use a crank trigger on the timing cover, not in the distributor. Along with having the ICM on a small heat sink mounted somewhere on the engine.

Replacing that ICM with a small cap 8-pin module should do the trick. This will allow the ECM access to an EST/BYPASS line so that handshaking is complete and code 42 won't appear. And allow the use of the stock Vortec distributor and crank trigger.

RBob.

 

After comparing Alldata diagrams, It may be possible as you say, If the crank reference signals are the same. But I think A trip to pick and pull is alot easier!

 

So 99 vortec 4.3 long block,should i start with the 4.3 timing tables or the vortec 5.7 tables?

 

I'd try the 5.7l Vortec timing tables first. If GM used the same chamber design and a similar cam they will be a drop in. Can also set up a calibration with the standard/early 4.3l SA tables. Easy enough to flash in the two and switch between them.

RBob.

 

Hi everyone.

Another EBL noob here!
I converted from a 165 ecm to the EBL P4, car is an 87 GTA with a mild-ish 383 First TPI intake

I have a starter bin to work with, I think I have most of the proper flags and scalars set, and have done a few ve learns to date. I have looked through this thread but cant seem to find an answer to my problem, so I thought to ask for some help.

My issues:

Fan #2 is on at WUD but off at fan. Fan does work when grounded, not sure if i goofed the repin here( dont think so), or other possible issue? I could jump from fan 1 to 2, I dont mind both coming on in unison if need be.

Second issue is my speedometer reading is off. I used the stock vss settings in the ebl bin file 3005. So now my WUD speedo reads 30mph when i am doing approx 50, so it is way off. I still need to install the correct speedometer gear in the tranny since my gear change, but i dont know if it would cause this much of a gap in readings? My clusters speedometer is off by about 15 percent.

This vss issue may be the cause for my third problem. Torque converter is not locking. Tcc flag is set, but i may have missed something. TCC does not flag on in WUD, even at speeds greater than 60mph. Not sure if i missed another flag or scalar setting. MY gear selector is working correctly and displays P/N in park and neutral, and 1/2 in drive, Od in 4th.
I have enclosed a photo of all the settings i can find regarding the vss and tcc settings.
Does anyone see a mis-match of flag settings or any other ideas to my situation?

I will say that so far i love the EBL, been only a few days messing with it but I know i will continue to enjoy it.


Thanks for looking.

 

Vss ppm should be 2002! I've been asking so many questions in here myself I'm glad to finally be able to contribute something.

Also, I don't think the secondary cooling fan in our '165 cars was controlled by the ECM. Did you run extra wires between the ECM and secondary relay?

 

lol, thx.
I'll try the vss change.
#2 fan on 165 ecm was controlled by the temp switch on right side head and or the A/C switch. i didnt know i would need to run a new wire to ecm to control it with the the ebl?
I just looked at the p4 wiring schematic, and you are right, need to run the F pin from relay to f8 at ecm. Thx for the heads up.

 

Here is one I don't beleive is related to the tune. I have an EBL flash unit and every once in a while when sitting at a stop light the idle jumps from 850 to 2000 and then slowly comes back down to 850 over the next 30 seconds. I don't beleive it is tune because I caught it on a log and found that the communication to the WUD was getting lost as the run time reset to zero for a few scans, then, everything went crazy for one scan, and then the fast idle started. Just like I had restarted the car. I have seen this before in the log when running at highway speed but thought it was my USB port since there were no ill effects on the motor running. However, when idling, it kind of gets your attention when the car jumps forward on a fast idle out of the blue. Has anyone else seen this? I am guessing I need to start wire chasing to see if there is a loose wire somehwere. Any suggestions where to start?

 

The EFI harness grounds on the engine block is the most common area of problems.

RBob.

 

Sounds like the ECM resetting.

 

So the vortec 4.3 was i believe about 200hp 260tq. Its running an edelbrock performer intake, no cats, free flowing exhaust. Would i be better to start with the 4.3 bin or 5.7 bin.

 

From a couple of posts up:

Grab a 4.3l BIN and copy the main & extended SA tables over from the supplied Vortec BIN. Be sure to set up the BPC - BPC vs VAC table for the engine displacement and injector flow.

RBob.

 

I planned on using the vortec timing tables first. Just wasent sure what bin would be closest from a fueling standpoint since thw vortec 4.3 is higher power than tbi 4.3. Also will 61lb injectors be to much. Maybe run a lower fuel pressure?

 

I wouldn't run lower then 13 psi for fuel pressure. The 61#/hr injectors look to be just about right. Plug the numbers into the EBL Utility.

RBob.

 

Better off with smaller injs at higher pressure but you need a fuel pump that can accomodate. TBI injectors are good up to 35 lbs I hear. Maybe higher.

I run 75's at 26 lbs. seems car runs better at lower loads when pressure was cranked up from 19 lbs.