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Grams per second, from a purely mathematical / theoretical standpoint, should be about 1 gram per second, per 1 liter of engine displacement at a "normal" (factory) idle speed - usually about 550 - 650. That's a general rule of course but it's usually very, very close to that. So on a 305 you will generally see about 5 grams per second at idle. On a 350 you will see about 5.7. When you get into looking at other engines - say 4 cylinder engines for example - they naturally idle higher due to having fewer firing events per rotation so the idle is higher to smooth them out. A 2.5 L 4 cylinder with a factory idle of 750 RPM will usually be about 2.8 to 3.0 grams per second at idle. This is from experience working with engines that have MAF sensors and watching factory calibration live data.
GD
So my 350 with a mild cam idles at 750 rpm's and reports 21
gms sec. (EBL Flash) How would I correct that ?
So my 350 with a mild cam idles at 750 rpm's and reports 21
gms sec. (EBL Flash) How would I correct that ?
Basically you reduce the scalar "AirFlow - Displacement Scalar" until the the grams per second come down into the range that makes sense. I had to reduce the scalar on my 305 to 153 to get a reasonable value. I consulted Rbob who agreed that this was the best way to get the desired airflow values.
So my 350 with a mild cam idles at 750 rpm's and reports 21
gms sec. (EBL Flash) How would I correct that ?
I would think you would be seeing a bit lower then that with a 350 and only mild cam. What are your cam specs? Seems weird how a mild cam 350 idling at 750 rpm is only 2-3 G/S lower than my 406 with a "large" cam idling at 900 rpm.
Have you tuned SA and VE tables to give lowest KPa at a stable idle? What KPa and SA are you idling at?
GD: What are the more in depth benefits of "correcting" that number down to a sub 10 range? From what I have seen, some closed loop calcs use it and the IAT Compensations use it.
On a WOT pull at 5200 RPM (highest recent pull I have recorded) I see a high of 240 G/S. The max is 255 correct? As long as I stay below that 255 value I am still "in range" and wouldn't necessarily need it to be changed/corrected?
[QUOTE=dabomb6608;6337795]I would think you would be seeing a bit lower then that with a 350 and only mild cam. What are your cam specs? Seems weird how a mild cam 350 idling at 750 rpm is only 2-3 G/S lower than my 406 with a "large" cam idling at 900 rpm.
Have you tuned SA and VE tables to give lowest KPa at a stable idle? What KPa and SA are you idling at?
It's a hotcam, 218, 228 degrees @ .050. Idles at 750rpm's, 51KPa, SA is 29 degrees. Idle is really stable. Just curious as to why the G/S was so high. Or if it really makes a difference.
Having the airflow number read correctly gives you the full range of the compensation tables that use it. Having it read abnormally high invalidates the lower rows of those tables because they will never be used.
Grams per second is also a relatively close approximation of HP. The relationship seems to be about 1.2 grams / HP. So take peak grams per second, times 1.2 and you get about crank HP. Or just simply grams per second is approximately your wheel HP after drivetrain losses.
It does max at 255 in the firmware of most of these ECU's. That's a software limitation and does not reflect what the actual flow rate is doing. Grams per second are still increasing beyond 255 you just can't see it.
GD
Last edited by GeneralDisorder; 11-01-2019 at 08:13 AM.
No need to change the VE tables. There is a handful of AFR values & tables that should be changed. Here are the values and tables to change for E45:
RBob.
RBob, any thoughts on this? I'm a bit confused. I've made the changes recommended above while running a half tank of E85. And my cAFR does show 12.1 in the WhatsUp display. But my AFR is almost always running in 14 or 15 range. I've increased the VE tables thinking that would help bring it toward the 12.1, however now I've noticed the BLM is running frequently at 108. Doesn't 108 mean its trying to remove fuel?? Why is is it trying to remove fuel when the actual AFR is leaner than what is being commanded?
A BLM of 108 is removing fuel. How accurately were you able to measure a 50/50 mix of E85 and gasoline?
RBob.
I think my 50/50 mix is pretty close. +/- 5%
I did not change anything in the wideband setup, only the changes you suggested above in the BIN. Did I miss a step ?
A WB sensor reports in Lambda, the controller converts that to an AFR. Gasoline is stoich at 14.7:1 AFR, which is why the WB is reporting in the 14 - 15 AFR range.
RBob, any thoughts on this? I'm a bit confused. I've made the changes recommended above while running a half tank of E85. And my cAFR does show 12.1 in the WhatsUp display. But my AFR is almost always running in 14 or 15 range. I've increased the VE tables thinking that would help bring it toward the 12.1, however now I've noticed the BLM is running frequently at 108. Doesn't 108 mean its trying to remove fuel?? Why is is it trying to remove fuel when the actual AFR is leaner than what is being commanded?
I assume you are using the narrow band factory style (or three wire heated) narrow band O2 sensor for closed loop? It also will read lambda - remember that the O2 sensor only reads Oxygen. It knows nothing other than the ratio of oxygen in the exhaust to that of the regular atmosphere. stoich is the point at which all the fuel is combined with oxygen in the most efficient combustion. Lean means there was surplus oxygen in the exhaust, and rich means there was surplus fuel (zero oxygen) and it can tell this by way of some chemistry with ions and such that I really don't understand..... So regardless of the fuel used, the sensor is going to report the same if you convert to Lambda.
Note that this is why the O2 sensor reads lean when you get a misfire - even though the exhaust is "rich" with unburned fuel, it is the unburned oxygen being read by the sensor and this is interpreted as a lean condition as if there was not enough fuel to burn up the oxygen - when in actuality the issue is that no combustion took place to burn either.
GD
Last edited by GeneralDisorder; 11-05-2019 at 12:47 PM.
I assume you are using the narrow band factory style (or three wire heated) narrow band O2 sensor for closed loop? It also will read lambda - remember that the O2 sensor only reads Oxygen. It knows nothing other than the ratio of oxygen in the exhaust to that of the regular atmosphere. stoich is the point at which all the fuel is combined with oxygen in the most efficient combustion. Lean means there was surplus oxygen in the exhaust, and rich means there was surplus fuel and more oxygen was consumed than would be in a stoich combustion. So regardless of the fuel used, the sensor is going to report the same if you convert to Lambda.
Note that this is why the O2 sensor reads lean when you get a misfire - even though the exhaust is "rich" with unburned fuel, it is the unburned oxygen being read by the sensor and this is interpreted as a lean condition as if there was not enough fuel to burn up the oxygen - when in actuality the issue is that no combustion took place to burn either.
GD
Would a change in the rich, lean, and mean r/l O2 tables be required, due to the change in what the stoich ratio is for his E45 vs standard unleaded? That is to say, does the fuel/alcohol blend affect where the O2 cross-counts occur in the voltage range of the sensor?
Would a change in the rich, lean, and mean r/l mV O2 tables be required, due to the change in what the stoich ratio is for his E45 vs standard unleaded? That is to say, does the fuel/alcohol blend affect where the O2 cross-counts occur in the voltage range of the sensor?
To expand on Rbob's answer.... "Lambda" doesn't care what fuel you are using. Lambda is the point at which all oxygen is consumed in the combustion process (stoich), and whatever that ratio is, will yield a Lambda of 1.0, or about 0.45v on a narrow band. The sensor ONLY cares about oxygen content - it doesn't know what fuel is being used. Stoich is EQUAL TO a Lambda of 1.0 with ANY fuel. A wideband that is setup to read gasoline will *display* 14.7 AFR when the sensor reads Lambda 1.0 - regardless of what fuel is being used. It will be wrong of course, but for the purposes of tuning Stoich it really doesn't matter..... E85 Stoich is about 9.8
The narrow band ONLY reads Stoich. It is pretty much useless for anything but. And it will read approximately 0.45v at 9.8:1 with E85, just as it reads at 14.7:1 on gasoline.
And this is yet another great example of how you can't really dial in your speed density tune (or even MAF tune really) super close tolerance and get all totally **** about the BLM's and INT's. When you start adding in 10% or 15% ethanol it changes the stoich of the resulting mixture. E10 stoich is 14.04:1 AFR and E15 stoich is 13.79:1 AFR....... fuel blends change with the seasons most places in the US and even E85 can be anywhere from E60 to E90 at the pump. Unless you buy racing fuels that are carefully blended and tested.... you can get all kinds of weird stuff from your local gas stations.
GD
Last edited by GeneralDisorder; 11-05-2019 at 12:38 PM.
I have recently installed the EBL in my '76 GMC Motorhome and it is running pretty well except at idle before Closed Loop kicks in. (BTW, I am a real newcomer at this tuning stuff, although I can follow directions enough to modify the BIN and flash it).
I am seeing excursions of RPMs from 615 down to 415 and back every four seconds. In the graph below, the y-axis is seconds from startup.
I have recently installed the EBL in my '76 GMC Motorhome and it is running pretty well except at idle before Closed Loop kicks in. (BTW, I am a real newcomer at this tuning stuff, although I can follow directions enough to modify the BIN and flash it).
I am seeing excursions of RPMs from 615 down to 415 and back every four seconds. In the graph below, the y-axis is seconds from startup.
Bill,
Looks like a lean surge to me. Notice how the WB approaches ~15+ as RPM rises, and the NB voltage drops to zilch. Not that they're very accurate when cold, but this would indicate conditions too lean for steady-running cold startup.
I would add to the choke fueling if this problem goes away on its own quickly (i.e. during the choke period). If, on the other hand, it persists for a few minutes, and/or only occurs when cold, try instead adding to fuel vs CTS at lower temps.
The VE is changing pretty dramatically with the surge - makes me think the VE map is not flat in the idle area. You really need to keep the idle area of the VE table pretty flat or any little idle variation will setup a surge as the fueling goes rich and lean and the closed loop tries to correct the situation.
Here is the VE table... I've done a few VE Learns - some at idle. Actually, Closed Loop settles the idle down pretty well. All this is happening in open loop.. It starts about a minute after startup and gets a little better after a couple restarts but doesn't really settle down until Closed Loop at nine minutes.
Here is a snap of the whole run.. Let me know if you would like me to annotate this.
You have the graph annotated that the VE is dropping down to 40.... I don't see that in your table.
I don't know what RPM and MAP those graphs represent either so I'm not sure where in the table the surging is taking place. What RPM are you at during warmup?
Also your VE table is skewed pretty high. The top of the map is already at 99.2 (100 is the max) at WOT, 2000 RPM. That doesn't leave room to go higher in the next table... I know it's a motorhome but the engine definitely won't be all done at 2000.
GD
Last edited by GeneralDisorder; 11-28-2019 at 09:31 AM.
That 40% VE note was me in a hurry, I guess. I'm attaching another snapshot of about four seconds of data at 76 seconds from cold start. There are vertical lines with the values noted, one at 400RPM at the bottom of a cycle and one at 600RPM. The period of these cycles is about two seconds. The previous plot represents about eight minutes of running, with the worst cycling happening from about one minute into the run until about five minutes. The bottom red trace is RPM.
Don't know what to say about the 2000RPM column in the VE table... This is a BIN that all of the GMC Motorhomes are using. 2000 RPM represents 50MPH with my final drive ratio.
I reverted to an earlier BIN to remove some VE learns that changed the low speed VE table in the idle area and tried again. I no longer had the surge, but the idle speed was still low until it went into closed loop. The IAC went from its park position at startup to 145 steps in about 5 seconds and stayed there through closed loop start until the coolant temperature reached 160 degrees, after which it slowly decayed to zero steps.
The only parameter in the BIN that makes any sense is the IAC-Max Steps scaler that is set at 145. According to the IAC-Powerup Init Steps table it should have been at about 100 for a coolant temperature of 40F (cold engine).
Well, I bumped up the Open Loop - AFR Multiplier vs CTS numbers by three from 8C upwards (8C changed from -14.06 to -17.94 and so on) which raised the idle RPMs after startup enough to be about the same as when closed loop takes control, which makes the whole startup process seem smooth (enough), so I don't really need to worry about the IAC going to 145 I guess. Once the engine warmed up, I shut it down, waited 10 seconds, and started again. This time, the IAC parked at 67 for a few seconds and then dropped to 21 and held, so I think I have the IAC/Throttle Screw settings about right. A little more tweaking should get it to 10 counts which is where I believe it should be.
This time, however, it failed to start a couple times until I gave it some throttle. So something else to worry about.
Hello all
i been away from the forum for a few years
well I haven’t driven the bird much but long story short
i took old combo out and im in the process of over hauling the tierd 383
it made about 500hp
im changing a few things now
new heads and solid roller cam (old cam was hr)
it should yield about 600hp now
my question is the following i was previously running accel 30 lbs injectors but they where on the limit around 90% duty cycle
with an extra 100hp more and more rpm than previous combo
should i get 42lbs or 60lbs injectors?
this is a street car so i want to retain same or similar street manner as before
what injectors you guys recommend?
Is there any way to run open loop up to 1200 rpm's and closed loop above that with the EBL flash? Just curious, I am happy with the open loop tune I have now but I can't stop messin' with it!
Recently started running a EBL-P4 on a 350 TPI (L31 Vortec) and the car stalls and dies on initial start up almost immediately, second try the car runs for a little longer then stalls. On the third start up it will stay running. The car also stalls when shifting out of park or from reverse to drive. Where do I start on trying to fix this
The car seams to run rich at low RPMs but have not data logged it as of yet
Hi guys! Just started tuning my new engine combo with the EBL w/Port Mod. It's a 350 w/ MPFI. Has a small cam (212/218 112 LSA hyd roller) w/EQ Vortec hybrid heads. I'm having an issue with warm up just after a cold start. It fires off fine, then within a few seconds, it begins running rough. It does this until about 1 min after start and then smooths out and idles fine. Looking at the logs, the RPM readings are erratic while it runs rough (sometimes all the way up to 2500 rpm which is isn't actually doing). Once the RPM reading settles out, the idle settles out also. Any ideas where to start searching for the source of my erratic RPM readings? Log attached.
Hi guys! Just started tuning my new engine combo with the EBL w/Port Mod. It's a 350 w/ MPFI. Has a small cam (212/218 112 LSA hyd roller) w/EQ Vortec hybrid heads. I'm having an issue with warm up just after a cold start. It fires off fine, then within a few seconds, it begins running rough. It does this until about 1 min after start and then smooths out and idles fine. Looking at the logs, the RPM readings are erratic while it runs rough (sometimes all the way up to 2500 rpm which is isn't actually doing). Once the RPM reading settles out, the idle settles out also. Any ideas where to start searching for the source of my erratic RPM readings? Log attached.
Hi guys! Just started tuning my new engine combo with the EBL w/Port Mod. It's a 350 w/ MPFI. Has a small cam (212/218 112 LSA hyd roller) w/EQ Vortec hybrid heads. I'm having an issue with warm up just after a cold start. It fires off fine, then within a few seconds, it begins running rough. It does this until about 1 min after start and then smooths out and idles fine. Looking at the logs, the RPM readings are erratic while it runs rough (sometimes all the way up to 2500 rpm which is isn't actually doing). Once the RPM reading settles out, the idle settles out also. Any ideas where to start searching for the source of my erratic RPM readings? Log attached.
After looking through many logs of this problem, it seemed to me that the problem had to be something time related in the tune as it always cleared up around 55 seconds after start. The places where the RPM went haywire in the log all had 35-40 degrees of timing and had decayed to around 32 degrees when the problem stopped, so I shot for no more than 30 degrees during warm up. That change fixed the rough idle, and the erratic RPM reading. I thought maybe the distributor had moved and the timing was off, but it wasn't. So, I'm glad the cold idle is better, but what would cause the erratic RPM reading when the timing is high?
I would check the distributor, cap and rotor to start with. Also check that the base plate is still firmly attached to the distributor body. Along with the star wheel still firmly attached to the shaft. Could also be that the plug wires are going away, or even the spark plugs.
Finally after winters break the van is back on the road and I am trying to improve the closed loop behavior. Maybe you guys can help with some weird issues that I am experiencing:
The WB O2 is always reporting a rich mixture in closed loop. Even after extremely lowering the O2 window terms the average WB O2 still reports rich (for example the idle r/l term was lowered to 250mV and idle was still rich at about 14 average with a swinging delta of ~1,5).
Could this be a faulty NB O2? The Innovate WB was freshly calibrated.
In general I have big problems to get proper NB swings at low (no) load & low rpm. In neutral the NB swings look pretty erratic until ~2000-2500rpm. Below that rpm the NB reading stays at the top & bottom for almost a second sometimes.
Above this rpm the NB swings look like a nice "sine curve" but the delta of the WB swing is sometimes up to 2-3 AFR (you can also hear that "bad u-joint noise" of too much Prop Gain along with a slight surge).
I played a lot with the Prop Gain vs. Airflow factor but I got either huge delta on the WB or the Prop Gain was not enough to get a proper NB swing.
Any thoughts on this? Could O2 error vs. Prop Gain be the better adjustment?
By the way: The sensors are sitting just behind the headers. NB is converted to a heated sensor. The INT delay has already been increased to account for the transport delay. Should the Prop Gain duration also be adjusted?
One more thing:
Wideband VE learning totally kills the VE tables at low rpm & kpa. It adds/subtracts way too much of the VE table so the AFRs are totally out of range after updating to the new BIN. Is there a way to reduce the calculated VE change? Or is there a possibility to reduce the maximum allowed addition/subtraction? If I understand correctly the standard maximum of VE change is +/-12, correct?
Hi all finally got around finishing the engine ready to drop it back in
to start i have 383 solid roller now .618 lift
Afr 227 heads cnc flow 318cfm at .650
hsr intake
the only changes i made from before are heads , cam and injectors 60lbs
previusly i had a hr cam 540 lift
and accel 30lbs injectors
on my previous tune i was at 95% duty cycle
so I decided to go to a better injectors and bigger since i have way more cam and heads
The questions i have now are what numbers do i put for the following
injectors correction offset?
single fire mode pw?
small pw correction?
hey guys I need some help with my tune can someone take a look at my data log im concerned about my O2 swings they don't look right but not sure smells a little rich but BLM say im close to 128 +- 3 also my launch mode light comes on while idle in park and in gear same with my async light stays on not sure what that does any advice would be much appreciated
hey guys I need some help with my tune can someone take a look at my data log im concerned about my O2 swings they don't look right but not sure smells a little rich but BLM say im close to 128 +- 3 also my launch mode light comes on while idle in park and in gear same with my async light stays on not sure what that does any advice would be much appreciated
The LM mode activates as the delta MAP value to enable it is set low. Increase this value by a few KPa: LM - Delta MAP Threshold Enter
The ECM is sitting in async injection mode, you can eliminate async mode by zeroing this table: INJ - ASync Transition PW - TBI Only
Doing that can sometimes help with a more stable idle. Just something to try and see how it is. Async mode is used when the injector PW gets small.
As for the O2 swing, not enough proportional gain at idle. The INT is moving a little to get x-counts. To adjust just for idle, add a little to this parameter: PRP - Prop Gain Multiplier for Idle (Airflow)
Can also add duration via this parameter: PRP - Prop Gain Multiplier for Idle (Airflow)
Well, I bumped up the Open Loop - AFR Multiplier vs CTS numbers by three from 8C upwards (8C changed from -14.06 to -17.94 and so on) which raised the idle RPMs after startup enough to be about the same as when closed loop takes control, which makes the whole startup process seem smooth (enough), so I don't really need to worry about the IAC going to 145 I guess. Once the engine warmed up, I shut it down, waited 10 seconds, and started again. This time, the IAC parked at 67 for a few seconds and then dropped to 21 and held, so I think I have the IAC/Throttle Screw settings about right. A little more tweaking should get it to 10 counts which is where I believe it should be.
This time, however, it failed to start a couple times until I gave it some throttle. So something else to worry about.
Just some feedback for anyone following this earlier issue... When I installed my EBL/ECM, I assumed that all 12v power came from the IGN source. Once I connected the BAT +12V to the proper terminal the IAC started to park correctly and now startup and idle works great. Thanks for all of the help - no one could have imagined that someone would make such a boneheaded mistake.
hey guys very new to this so please be patient with me but im mechanically incline and been messing with many third gens for over 20 yrs but been doing so un tuned
got in the mail today installed the exterior comm cable lucky i didnt have to move any wires
1st question can i use the cars original ecu (bought the package deal with it preinstalled on a ecu so i have two ecus now ) with the comm cable installed in my harness?
did a little tinkering with the latency on my laptop but did get the WUD to work i can see some of the parameters light up with key on and the tps voltage reads correctly
pretty late in the day now so i stopped there i need to know how to get one of the supplied bins in the new ebl ecu i believe thats the next step?
what i did so far installed tunerpro on laptop (is this the preferred program?) installed the supplied cd that came with the ebl along with whats mentioned above
one more question whats the prom slot in the ebl for can i just install my prom in there to get the car to turn over?
hey guys very new to this so please be patient with me but im mechanically incline and been messing with many third gens for over 20 yrs but been doing so un tuned
got in the mail today installed the exterior comm cable lucky i didnt have to move any wires
1st question can i use the cars original ecu (bought the package deal with it preinstalled on a ecu so i have two ecus now ) with the comm cable installed in my harness?No.
did a little tinkering with the latency on my laptop but did get the WUD to work i can see some of the parameters light up with key on and the tps voltage reads correctly
pretty late in the day now so i stopped there i need to know how to get one of the supplied bins in the new ebl ecu i believe thats the next step? If you're hooked up, go to where you select bins to flash to the ecm. Flash one of the starter bins. They are a great place to start. Choose one that is close to your setup, but the stock configs are pretty good to get you up and running quickly.
what i did so far installed tunerpro on laptop (is this the preferred program? Yes.) installed the supplied cd that came with the ebl along with whats mentioned above
one more question whats the prom slot in the ebl for can i just install my prom in there to get the car to turn over? Select a starter bin file to flash, and flash it to the ecm. Don't try to remove anything from the EBL. It is different than your stock ecm (at least it is where the prom is located). Everything is flash based, so there is never a reason to remove anything.
thanks
Make sure you read through the two introduction to tuning pages on dynamicefi.com. It outlines what you need to do to get going initially. If you still have questions, this forum (and specifically this thread) are great resources.
reading through now, alot to read theres even more about the WUD on the cd that isnt on the site luckily my setup isnt to radical that i can get away with a stock tune until i can get it on a dyno i did get the 3005.bin 350 tpi auto bin loaded up and fired the car up just want to change a few minor things to get the hang of this before going deeper doing the WB VE learn maybe even taking some of the aluminum headed 3006.bin and incorporating into the 3005 as i have aluminum heads
going through tuner pro just to check things out but i cant find how to change C to fahrenheit no biggie also under flags "Option Word 3 - Bit 0 - Vats" the supplied bin has "Set" unchecked does that mean vats is already disabled in this bin? also noticed "EGR -CTS Enable Threshold" is already set to 150 C which means its also disabled?
"The Action radio buttons select whether to program or read/save a calibration.
The boxes to the right of the Action box show the currently selected calibration files (the BINs). They will gray/activate when switching between Program and Read. To read a calibration click on the Read radio button. Then click the Select BIN button. You can type in a file name that the calibration will be saved to."
"The Options box allows the flashing to be verified (read back and compared) and the flashed-to bank to be made the active bank.
A verify is a good idea "just because."
The Set Bank Active ensures that the ECM will be running from the calibration that was just flashed. In general it is a good idea to round-robin through the calibration banks. This allows you to back up a tune if something was set incorrectly during editing of the last calibration."
which should i use every time i change or upload the bin, program or read? then after that is it necessary to verify and set bank
can not find the VE learn files i see them when in the ebl program together with the other bins under the default user calibration folder but when i go to
windows(C) > program files (x86) > dynamic efi > ebl p4 flash > user calibrations there not in there with the other bins
when the 2nd pop up window opens in ebl after i select learn VE called "select file to create new bin" if i change it to desktop instead of leaving it in user_calibrations then i can access it and load it in tuner pro
10-30-2019, 07:41 PM
