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Need to increase the VE% where it is lean. Should also verify that the fuel pressure is holding.
With little headroom left in the VE table, increase the BPC - BPC vs VAC table by 15%, and reduce the VE tables by the same 15%. Continue on.
RBob.
I increased the BPC - BPC vs VAC by 15%. Wow that got the fuel into it up top. Wot pulls up to 5500 rpm were showing mid/high 12s afr. I didn't touch any of the ve tables yet. It's idling Rich around 13 but also not dipping or surging.
I was going to do some more logging and SA changes but my passenger collector bolts fell out creating a big exhaust leak.
Last edited by 89fast5oh; May 28, 2023 at 03:39 PM.
The SA - Main Table values indicate a timing value. Are those values the final total timing? Or does those values get added to the base 10 degrees to form the final total timing?
ie; the SA - Main table shows 21 degrees at 3600 rpm. Is 10 degrees initial added for a combined 31 degrees at 3600 rpm?
For my tune I am running the vortec spark tables with the AFR 195 enforcer heads. I think along the way I read that the vortec timing was a good one to run. But now I am not sure. At WOT I am only going to get 30 degrees of total timing. Seems low.
Alright I've done some more BLM VE learns and got my low speed table to be pretty smooth aside from a bowl around the low rpm / high map area. Not really sure what I can do to get coverage there on my learns since I have a 700R4 and cannot force high loads at those rpms easily.
I am also now having an issue where turning the A/C on while the engine is idling causes it to stall every time. Seems to happen both in closed loop and open loop. I have also had the engine stall after I turned off the A/C after it had already been running and I went to park the car.
It is just an 87 LB9 with an intake and exhaust. I am not sure why it is struggling so much at idle. I am attaching a short datalog that shows the stall in both open and closed loop and the bin I am using.
Last edited by Rainmaster; Jun 4, 2023 at 09:10 AM.
With the closed loop cts threshold changed to 150c and the ccp vacuum line plugged I, I've been doing ve learns.
I noticed in open loop the cAFR varries depending on driving. I'm talking about easy stoplight driving no wot or heavy throttle.
If the cAFR is changing, how does the ve learn properly work?
The tune seems to get the ve close, but then back in closed loop operations, the blms are varying from 128 at idle down to 120 or lower.
I'm also having the same problem as a poster a few above. I have the data sheet for my wideband, entered the data as per, but the WB gauge readout and the WUD display are off by half to 1 full point. And it's not linier, say at 13:1 it's showing 13.1-13.3, but at 14.7 its showing 15.5.
If the WB data being seen by the ECM is bad, then the VE Learns will be bad. Garbage-in, garbage-out.
RBob.
This is what I have programmed into WUD.
This is the AEM WB data. I have the gauge wired in as follows: BLK to car ground. RED to switched 12v. White signal analog + to EBL FLASH II. 3 wires, that is how it was hooked up to the stock ECM. Perhaps I do not have it wired correctly?
Connect the brown analog wire to the EBL ECM GND terminal (left two most are GND, on the EBL Flash-II).
Be sure that you selected the user device that you created. Along with the correct ADC channel (WUD preferences).
See if it is better. If not then measure the voltage output from the WB controller and see if it matches the gauge AFR.
RBob.
I had it wired as stated in the instructions as the least desired option. I connected the brown analog wire to the EBL ECM GND terminal. The WUD display and the WB gauge now appear to display the same information.
I would also like to understand how the VE learns in open loop.
While in open loop doing VE learns the cAFR moves around due to the Open Loop - AFR vs RPM & VAC. Goes anywhere from 12.8-15.3 according to that table.
Back in Closed Loop if the target for street cruising is 14.7, isn't the ECM going to have to make lots of changes to the BLMs trying to get the AFR close to 14.7?
Maybe this is correct, but its leaving me too lean now. Here is a log of cruising around with a couple WOT at the end.
Easy, in open loop via a WB learn, the WUD compares the cAFR to the WB reported AFR and adjusts from there.
In closed loop the WUD just uses the BLM value.
When doing VE Learns, easy on the go-pedal. Hold it steady at various RPM & load areas. But hold the pedal steady.
RBob.
I am very new when it comes to tuning and understanding how things work. Is what I think correct? The VE learns gets the VE tables close so that cAFR and actual AFR pretty much match. Then once back in closed loop the BLMs move around to add or subtract fuel to get the AFR to match the cAFR depending on what is happening, ie, idle, varying cruise etc?
So how come after VE learning and back in closed loop I steady cruise at 15.4-16.2? (not in highway mode) Shouldn't the ECM be adding fuel to bring that to 14.7? Am I missing something in the procedure?
That is some good information. My answer came from a old post of yours in the R/L threshold voltage thread.
Today's focus, now that I understand fueling a bit better is to settle on a spark advance table. I've been using the table that somes in the bin for 5.7 TPI auto.
The part throttle SA looks fine to me, but that SA at 90-95 kpa (where WOT is happening) is jagged, uneven, and reduces as RPMs go up.
I've been trying to look at other SA tables to get an idea of what they should look like. I've seen examples that are nice and smooth and increase until a total of about 34-36 then plateau until redline.
The '113 SA table does that, but is still jagged in places. Ive also seen people mention using the LT1 or LT4 tables.
My combo is 383", AFR 195 enforcer heads, Edelbrock pro Flo xt 4 intake, comp 08-502-8 cam, 700r4 3.23 gears.
Last edited by 89fast5oh; Jun 6, 2023 at 08:09 AM.
I was using the timing table that came with the 5.7L TPI Auto bin but wanted something with more linear advance. Instead of reworking that one I used the Building Spark Advance Table excel spreadsheet. I put in that I wanted 34 degrees maximum advance and Limit to Maximum Advance above this kPa: 90. I used 90 kPa there because I am focused on max WOT performance, and 90-94 kPa is where it holds at WOT.
Car runs great with the new table. No knocks at all, which is both good and worrying. When I built the engine I used a new knock sensor. The WUD shows knock counts at engine shutdown, so I guess it is functioning?
I'm having an issue with hot restarts.
Pretty much if I shut off the car when it's something around 220F and come back 20 or 30min later, the car acts like it's flooding.
Cold starts are fine...
Starting the car while watching with a wideband O2, it shows a pretty rich fuel mixture and it runs a little rough for a bit, sometimes stalling.
Sometimes I need to crank for a while, flooring the pedal in hopes of clearing the flood.
I'm using most of the values from the 3001 bin..
Details that might matter, CFI injection, renegade intake that's been ported slightly, edlebrock heads (70cc), aremotive fpr with the vacuum reference connected to the intake, and 80lb injectors.
long tube Headers, dual 3in exhaust, 84 vette.
One thing I have not done, was to check the cts at key on...
Originally Posted by RBob
Increase the cranking AFR at the engine temperature where this occurs. Can also reduce the choke AFR in the same temperature area. Choke is really after-start fuel that is added for a short period of time.
RBob.
Originally Posted by Dominic Sorresso
RBob,
Could u clarify what u direction u mean by increasing AFR or reducing AFR.
Does INCREASE mean Richer, reduce mean LEANER? Just to be clear.
Originally Posted by RBob
The cranking AFR is actual commanded AFR. So increasing it is leaner.
The choke AFR is a value that is subtracted from the commanded AFR. So reducing it makes the final commanded AFR leaner (less is subtracted out).
RBob.
I'm having about the same hot start issues as above. I have a miniram style mpi intake system though and the ebl flash 2.
After shutting off the car when the engine is 200 degrees and going into a store and coming back out 10 minutes later, the car cranks and starts pretty fast, no extended cranking, but then the RPMs fall and it stalls. No surging or anything just starts then stalls. It will do this until I start the engine then hold the RPMs around 2000 for 5 seconds or so, then it will idle on it's own.
Does the above quoted information pertain to my issue? Is there something else I should look at?
The EBL system is expecting an IAT, not a MAT sensor. Grab a birdcage style IAT sensor (grommet or threaded, doesn't matter), and mount/locate it where it best reports the incoming engine air temperature. Where isn't always in the air induction system.
The EBL system is expecting an IAT, not a MAT sensor. Grab a birdcage style IAT sensor (grommet or threaded, doesn't matter), and mount/locate it where it best reports the incoming engine air temperature. Where isn't always in the air induction system.
RBob.
Other than the visual difference between a IAT and MAT, what is functionally different? As for placement, I've seen that V6 cars have a provision for the sensor right in the air filter intake duct. Would that be a better spot?
As for the birdcage IAT sensor, I've seen threaded, but not grommet. Any part numbers?
Other than the visual difference between a IAT and MAT, what is functionally different?
Uh, one reports the intake manifold temperature. The other reports the incoming air temperature.
And here is something that will throw a huge curve ball into this. Many times I've mounted an IAT where it isn't even in the incoming air stream. But behind the grill, off to the side/front under the hood. As I posted, it needs to report the best incoming air temperature. I have lots of posts on this.
As for placement, I've seen that V6 cars have a provision for the sensor right in the air filter intake duct. Would that be a better spot?
No, it is over the radiator and will heat soak at key off.
As for the birdcage IAT sensor, I've seen threaded, but not grommet. Any part numbers?
A '92 TBI Camaro/Firebird uses a grommet mounted sensor. Same as the '93 - '94 LT1 and others, and use a smaller different one. Many '94+ trucks also used one. I rarely buy new, rather hit the JYs and just pull sensors. Can't go wrong with GM stuff. And it is easy to test.
Uh, one reports the intake manifold temperature. The other reports the incoming air temperature.
And here is something that will throw a huge curve ball into this. Many times I've mounted an IAT where it isn't even in the incoming air stream. But behind the grill, off to the side/front under the hood. As I posted, it needs to report the best incoming air temperature. I have lots of posts on this.
No, it is over the radiator and will heat soak at key off.
A '92 TBI Camaro/Firebird uses a grommet mounted sensor. Same as the '93 - '94 LT1 and others, and use a smaller different one. Many '94+ trucks also used one. I rarely buy new, rather hit the JYs and just pull sensors. Can't go wrong with GM stuff. And it is easy to test.
RBob.
If I change to a IAT and relocate it out of the intake manifold, will changes to the VE tables be needed?
OK, what happened?! I programmed bank 0, with verify and set active. Now it's stuck in program mode with fans on. It was working fine-is it something stupid I did? How can I clear it? I've tried about everything from disconnect the battery to read program other banks etc.
Update- every time before when programming a bank-fans on until after program done then back to normal. This time it "stuck". Went back to try again-programmed bank 0 and same. Then went to bank select, changed banks and it cleared. Able to go back to bank 0 no problem. The engine isn't back together yet so I can't run it but all monitors on the WUD look good now as opposed to reading at zero before.
So what happened? I was going to try to "update" the ebl again but that failed, then the above worked.
RBob-I emailed you along with posting here. Thanks for any insight.
Further update-been trying everything going kind of crazy. It appears that when I read the most recent bin from bank 0 and then changed C.I. injector data etc. then reprogrammed it into bank 0 it got corrupted-don't know how. I tried a bin from the laptop from an earlier edit instead of trying to read the bins from the ebl and it all works as supposed to. It did sit for 10 years with no power to it before I got back to the car so I'm not sure if that had anything to do with it.
Last edited by drive it; Jun 20, 2023 at 07:13 PM.
Uh, one reports the intake manifold temperature. The other reports the incoming air temperature.
And here is something that will throw a huge curve ball into this. Many times I've mounted an IAT where it isn't even in the incoming air stream. But behind the grill, off to the side/front under the hood. As I posted, it needs to report the best incoming air temperature. I have lots of posts on this.
No, it is over the radiator and will heat soak at key off.
A '92 TBI Camaro/Firebird uses a grommet mounted sensor. Same as the '93 - '94 LT1 and others, and use a smaller different one. Many '94+ trucks also used one. I rarely buy new, rather hit the JYs and just pull sensors. Can't go wrong with GM stuff. And it is easy to test.
RBob.
I got the sensor and mounted it in the driver's fender space. Reads about 100 degrees less than coolant temp. Still getting heat soaked though. Will have to move it again.
Finally had some time this weekend to install Flash II in my van and did 4 or 5 VE learns and I have to say, this is a truly incredible setup, RBob. Really really impressed.
Running better than it ever has.
I feel like I've been catapulted into the 21st century. Bravo.
I just wanted to try something a different way I never ended up doing it from a data log.
The VE Learns are meant to get you in the right direction, but once you see your BLM is averaging stoich in a particular cell, you would then go into your editor and build your VE table around that one or two cells. Your stoichiometric value should never change once the cell you're working with is Learned, and if it does because of density, it is a very slight change that the ECM will of course correct for. When I tune for members, I only need an idle datalog for that reason... .
The VE Learns are meant to get you in the right direction, but once you see your BLM is averaging stoich in a particular cell, you would then go into your editor and build your VE table around that one or two cells. Your stoichiometric value should never change once the cell you're working with is Learned, and if it does because of density, it is a very slight change that the ECM will of course correct for. When I tune for members, I only need an idle datalog for that reason... .
- Rob
I've done some ve learns in OL but the problem I'm having is once the table is made and smoothed out, back in closed loop the BLM sits at 108 and INT in the low 120s indicating too rich. But if take more out of the VE table to lean it out it runs like crap, bucking, stumbling. So not sure where to go now.
in 8D on the 7730, i adjusted the target O2 voltages slightly rich allowing for a slightly richer VE table. The engine feels much more responsive during part throttle operation.
I would touch those areas depending on camshaft specs, especially if a member advanced the cam using the crank gear. A properly built engine with increased velocity from say a miniram would also benefit from tweaking that area, as AE would only be able to keep up with it so much before it bogs down, so the O2 thresholds are definitely a happy medium......
in 8D on the 7730, i adjusted the target O2 voltages slightly rich allowing for a slightly richer VE table. The engine feels much more responsive during part throttle operation.
I am still researching the O2 rich/lean, and mean R/L tables. I came across a video of someone tuning on a crossfire and at the point I selected he talks about dialing in those voltage tables using the WB readings so that the BLMs and INT don't have to fight to keep stoich.
On mine, I did it in closed loop, but with the help of the WB.
Basically I started increasing the O2 voltages until the WB showed AFR's that the engine liked. At light throttle, I left it at stoich. But moderate throttle (below WOT and w/o engaging Power Enrich), it seems to like about 13.5:1. It also provides a more linear/seamless feel between non-PE and PE.
When I got the AFRs to where I wanted them, the BLM's of course were much lower than 128. So then I adjusted the VE table to bring things back to ~128.
When changing fueling tables in the EBL, does the ECM memory need reset each time? I come from Ford eec-iv tuning and when changes are made the KAM (keep alive memory) needs cleared so the long term fuel trims are cleared so the new tune changes are apparent instantly.
Does flashing a new bin override and reset the memory? That might be covered the the EBL write up buty quick look came up empty.
I did another VE learn and the BLM/INT are leveling about 126/130. Not perfect but closer. I'm not gonna chase that too much. I'll do another VE learn though.
But now at certain cruise speeds/RPMs it feels a bit rough, surges at that speed/rpm, (35mph/1400rpm). If I richen it up with the VE table in the cells it needs, won't the BLM/INT start moving around to try and lean it out? Is that fine to do and leave like that or is there some other way to do what I want?
But now at certain cruise speeds/RPMs it feels a bit rough, surges at that speed/rpm, (35mph/1400rpm).
Make sure that the MPH threshold for lean cruise (highway mode) is higher then 35 MPH. Should be in the 50 - 55 MPH range. We had some BINs get set at 35 MPH, which doesn't work.
SA also plays a role, if the lean cruise is set OK, there may be too much SA.
If I richen it up with the VE table in the cells it needs, won't the BLM/INT start moving around to try and lean it out? Is that fine to do and leave like that or is there some other way to do what I want?
Yes, the fuel trims will lean it out. They go by the O2 window table values.
On mine, I did it in closed loop, but with the help of the WB.
Basically I started increasing the O2 voltages until the WB showed AFR's that the engine liked. At light throttle, I left it at stoich. But moderate throttle (below WOT and w/o engaging Power Enrich), it seems to like about 13.5:1. It also provides a more linear/seamless feel between non-PE and PE.
When I got the AFRs to where I wanted them, the BLM's of course were much lower than 128. So then I adjusted the VE table to bring things back to ~128.
Originally Posted by RBob
Make sure that the MPH threshold for lean cruise (highway mode) is higher then 35 MPH. Should be in the 50 - 55 MPH range. We had some BINs get set at 35 MPH, which doesn't work.
SA also plays a role, if the lean cruise is set OK, there may be too much SA.
Yes, the fuel trims will lean it out. They go by the O2 window table values.
RBob.
I did a longer more comprehensive VE learn. It seems to drive pretty well. Cruising around at a steady speed the BLM/INT are now almost on 128/128. There are a few spots that the VE learn leaned out, but the engine wants more fuel in those cells. If I add the fuel then the blm/int are going to start fluctuating.
I want to know if I need to adjust the O2 voltage tables? One thing I see when driving is at times the WB is showing lean or rich and the O2 NB reading is always around 800-900 mv.
Would anyone look at this log and tell me if things are on the right track to where they need to be or if there is a obvious problem that needs addressing?
If the engine wants more fuel and you don't want the ECM to trim it back out with lower BLM's, then you have to increase the O2 voltage swing points. I have my swing point into the ~750mV range at high map in order to get WB reported AFR's the engine is happy with at non-PE heavy throttle conditions, and yet still have the BLM's hovering around 128.
