What GM did on the '89 TTA's was to set an air flow threshold. Once the airflow exceeded this threshold the engine was considered to be in boost. With that the ECM's boost logic went into affect.

RBob.

 

Friends,
In the last year I made two projects with the family 7747 with success.
In the first, on a 67 camaro, with SB350 and powerglide I used a 7747 first and later a 8063. In the second, a 1985 Berlinetta, with SB305 and 700R4 I used a 7746.
Here in Brazil we have two types of fuel, E25 and E100.
I got a good adjustment of fuel and spark tables and, in both projects, the performance was very good, with space to get better still.
Now I upgrade the powerglide for 4L60e, and sure, I went to 16197427.
The basic setup, based on a BJYA is already working but I have some doubts for which I ask for help... I have been reading the subjects here in the forum and it is not spoken a lot in tuning.
1) can I use fuel and spark tables adjusted with 8063 in the new setup?
2) does exist some software to capture the values of BLM on tables as in WinALDL? Or do I need to extract these data of the TunerPro dataloging?
3) in the family 7747 it was clear where to modify AFR for E25. I don't see this very clearly in the 7427...Do I need to modify the tables ' WOT AFR vs RPM' and ' OL AFR vs Coolant Temp vs Vacuum' ?
I thank the time and the patience with my poor English (after all it is not my default language...)

Marcus
a friend from Brazil

 

1) Yes, you can translate your spark table over to the 7427 idle/run spark tables.

2) There are similar programs that you can use to capture and log the BLMs.

3) The short answer is that yes, there are values to modify. There is a stoich AFR value for closed loop as well as PE AFR and open loop AFR tables that can be modified for E85 fuel. The closed loop O2 PID gains may also have to be adjusted for the larger fuel injectors. There are various tables in the PCM to adjust for the AFR/PID gains/accel enrich/decel enleanment. Each one of these is a whole seperate topic all to itself, so the search button comes in handy for further discussions.

 

I'm very interested in this, because I have opted to bypass any supercharging or turboing, instead I plan on running a 2 Stage Kit of Nitrous. Keep us posted!

- B

 

Marcus,

I know that they have the answers to your questions well under way. I'll post some more info a little later.

How large can you get normal GM TBI injectors down in Brazil? 110#, 130#?

 

Beat me to the question

 

Thank you guys for replies..Sorry the delay.
dimented24x7, I'm doing a .adx for $0D so I'll use ScannerPro to track BLMs.
After this I'll have some path...Ah, fantastic your work on OD hack! Very hand.
Fast355, I'm using TBI Injectors from USA. I don't know what GM use here. I'll try to know.

 

I just read through this entire thread, and I am very impressed. I am a young EE and I am jealous of all of the hacking and reverse engineering that has taken place here. Not sure if I could do it.

Does anybody see why EBL wouldn't provide the mileage and general drivability improvements that I am looking for in my 9C1? I have done many iterations of tuning and even though the engine is pretty much stock with only better air intake and better exhaust, I feel like I honestly can't improve it any further. The cold start drivability has never been that good, no matter what I do, for example.

Compared to a '427, how does it stack up? How about a 427 running MAF? It seems like EBL (which of course has a lot of the 427 "real SD stuff" built in) is a HUGE step up from my dinosaur C3 ECM. Plus it's the only canned commercial solution. Even running a stock 427 would require a major re-pinning of my harness where EBL would not. And EBL provides niceties such as electric fan control, which I would like as I have dual electric fans.

 

Let me ask the question differently.

From a drivability and fuel economy standpoint, does a stock '427 have anything over an EBL? How about a MAF '427? Assuming the engine setup is mild (stock cam/heads), is a MAF '427 setup totally unnecessary? I keep reading how a wet manifold EFI system like TBI really needs a way to measure airflow directly to avoid the tune being off in certain conditions. Is this true?

Basically, I am looking for someone to convince me that EBL is what I want for my 93 9C1. I think it is, but I'd like to get a few opinions, even if they don't agree...

 

The place where the MAF really helps is if your running unheated manifolds. I ran an edelbrock airgap year round with a cold air intake when I still had the car on the road, and the MAF was manditory with that setup due to teh wide variance in manifold temps. Block of ice in the winter while in the summer it would be close to the operating temp of the engine in traffic.

With a mostly stock setup with a heated manifold, the SD should reasonably reflect the actual required fueling. They both have the same end result, which is to estimate the mass of air in each cylinder, but the MAF can do it directly which can have some advantages. Its more sensitive to airflow changes, so you need to take care when setting up the intake, and it will also lope like a carb if you run it with a cam that has overlap.

 

Thanks, I think that answers my question. I was not planning on doing any real modifications to my engine while using EBL. After I blow up my L05 (and/or 4L60) I will probably swap to a GenIII, like LQ4 or similar, and maybe T56.

 

I'm excited to see so much work being done on the 0D, since that's what I'm hoping to switch to soon :-). the $E6 xdf has something wrong with it when doing a checksum calculation so any edits I ever make (even if it's turning a flag off/on wont run in my truck since the checksum is wrong, goes to limp home mode)

I've got two questions:

Does anyone have any idea where I can find a .bin file for $0D that is from a 305? All I can find are 350 bins and I don't even want to try to edit a 350 file for a 305 (actually I did and it didn't turn out great).

Also, I understand you can open a .asm file in notepad and I saw all of the detailed info there, but (I know this is a stupid question but I looked around and couldn't get a straight answer) What do you do with it afterwards/how does it help me?

 

Hi gross, BHMC.bin for a 305 C1500 1994

w/t1500

 

Concerning the boost reference discussion, what do you guys think about adding a 2nd map sensor altogether?

I was thinking it may be easier then modifying any of the current settings and just have to work on adding code.

 

Hi friends,
I have been making some experiences with PCM 16197427 BDWM and in the part of the engine with reasonable success.
But, I am having a lot of difficulty with the transmission 4L60e, there are not shifts. All the time is in first gear. I already verified the solenoids. I removed the solenoids and I tested out of the transmission. Then, in operation, I worked the solenoids manually and the shifts happen.
I am using TunerPro and ScannerPro for diagnosis and I don't see PCM to command changes.
The transmission is 1998 with 3-2 downshift on-off (non-PWM) solenoid. Can be the origin of the problem?
Does anybody can help me?

Marcus

 

BDWM is the Export L31 TBI memcal. If I remember correctly these trucks had a 700r4 from the factory instead of the 4L60E. If that is the case and you are able to program try BJYM, BJYB, or BJYL.

 

Anyone happen to play around with the 427 ECM TIS A/C input? I was wondering what the stock trans. TIS A/C sensor output voltage min/max was?

I plan on using the input to read a dizzy reluctor directly if the ckt will sense the proper voltage level and zero-crossings. That is, ditch the dizzy module. Read the dizzy reluctor and switch/fire CDI box(es) for the coil(s).

 

Fast355: I do not think so....BDWM and BJYB looks very similar. Both has shift tables near identical. Anyway, I tried BJYB today with same result. Both solenoids On, no shifts, no codes.
My feeling is that I'm doing some little (or big) stupid thing....
Dimented24x7: you did a great job disassembling $0D. There are any secret to use 427 with 4L60e?

Has someone here using 16197427 with 4L60e?

 

Here is another thought, do you have a 40 pulse VSS in the tailshaft and a functional 93+ DRAC wired to both inputs in the PCM.

 

Yes, I have functional DRAC. I can see the speed on TunerPro. I put the car on stands. I run it at 35 mph on first....

 

Fast355,
Discovered!

Your last post made to bright a yellow light deep in my brain...
Despite ScannerPro show me the speed I got an scope and I went to verify the signs that leave DRAC and went to PCM.
Surprise! I didn't find 40 PPR signal. Verifying DRAC discovered that not even there was an 40 PPR output! I bought this unit in Ebay some time ago and I didn't notice the absence of this output...Fortunately I had another DRAC. I changed, and everything started to work! Now the 4L60e is shifting normally.

In my opinion, two stupid things:
a) two signs, leaving the same sensor, for speed measure.
b) no diagnose to indicate a code for the lack of the 40 PPR signal.

I hope this post can help others guys doing same job...
Now I'll do all tests and do some experience with shift points.

Again, thanks for your time.

Marcus

 

Yeah. Works similar to the TOS input, except that the internal counter runs 2x as fast. IIRC the trigger threshold is +/- 150 mV. Reads in the frequency, but you cant generate interrupts. The best way is to continue using the dist. pulse input. The DRP interrupt is the highest priority interrupt in the PCM, so it will always be serviced.

 

Thank you. That is great info. Yes, the DRP needs to be the highest priority. I will have to check the Ucontroller spec. and see if the interrupt priority is programmable. At one point I looked into it but time has slowly erased my memory.

I wanted to use the TIS because the engine has a reluctor/pick-up and no module. This would be the most simple design. The engine is a twin cylinder 180* engine with two coils. It has one reluctor/pick-up for cyl. #1 and triggers the "ignitor" which fires coil #1. Then 90* of the cam (180* crank) later the "ignitor" fires cyl #2.

So, what I wanted to do was read in the crank pick-up coil using TIS and fire the "ignitor" so that it took care of the two coils and timing between firing them. Since the interrupt priority seems to be a problem I will then install a GM dizzy module that will trigger the 427 ECM in the usual way. I will hook one 427 ECM output to a small AC pulse generator that connects to the "ignitor" AC pick-up input. The "ignitor" will sense this pulse and fire the coils at the proper time. Yes, it will take measuring to get the delays right.

 

I was wondering what you ended up using for PCM settings in the $0D for MPFI control.
I finally installed the 427 ECM with the $0D code on a TPI 350ci w/ 24lb/hr injectors.
I changed the injector constant to 12.3 grams/sec and installed the jumper wire on the MEMCAL for squirt every 4th DRP (double fire batch). I set the trans. bits to manual trans. and non-CC TCC. Start the engine and it ran, but a little lumpy at idle.

I tried setting the CPI/PFI bit to see how it would run. It wouldn't even start. So I am curious.........what did you set for the MEMCAL jumper wire, the CPI/PFI bit, the ASDF bit, and the injector constant.

After reading through the $0D code the CPI/PFI bit seemed like it would be the way to go, but I need to look into how it works when the MEMCAL has the 4th DRP jumper wire added.

 

I would start with one of the 4.3 CPI .BINs and tune from it. Thats what I did with my setup. You should remove and bypass the two current sense resistors in the injector driver circuits with short pieces of wire as well. This will eliminate the peak and hold action of the driver and revert it back to saturated.

 

That is a good idea in terms of starting with a 4.3L CPI bin. I don't have a mask BCC lookup tool or any V6 bins. Would you know which one of the bins at:
ftp://ftp.diy-efi.org/pub/gmecm/bin_...00D%200E%2031/
would be a good CPI starting point?

Did you do the MEMCAL jumper (squirt every 4th DRP) with the 4.3L CPI code?

I did the injector V_sense .10 ohm resistor jumper to ground for the 8 saturated injectors.

Thanks,
Junk

EDIT: I have a BNBJ MEMCAL that I think is out of a V6 CPI van.

 

I started with BNBJ which IS a 4.3 CPI. I don't know if it was a van or a blazer though. I simply set the injector size, cylinder displacement and count, timing table, TBI truck VE table, and transmission to my setup. Also make for sure you turn off the "fire all injectors each DRP" check byte. Otherwise it will run very rich or not at all.

I used the stock 350 TBI van memcal after adding the PFI jumper.

This was the first fire after swapping on the TPI. Its was running really lean due to a couple of moderate vacuum leaks (giant vacuum fitting on the TB).

http://s243.photobucket.com/albums/f...t=100_1240.flv

This is after some fine tweaking and splicing all the wires.

http://s243.photobucket.com/albums/f...t=100_1261.flv

 

The BNBJ that I have can out of an Astro van that was 4.3L CPI. I read out the BNBJ and set the #cyls, injector constant, manual trans, non-CC trans. I did not touch the "inj each DRP during crank" bit. In the code it appears to only change the inj. fuel during crank. It was set in the BNBJ bin, but not in the BDWM bin. Starting the engine on the BNBJ bin showed that it was rich and ran rough at idle and near idle.

The engine runs much better using the BDWM bin with the same mods. It has a slight lope that appears to be from how the fueling is performed. I then compared the option mode words L400B - L400F. The CPI setup is only slightly different than the TBI setup. I think the major difference is the few "fueling" bits. I am going to read through the code some more and test out some of the bit settings.

Also, I did a compare between the BDWM bin and the BNBJ and found that they use the same code. The calibration portion is different of course. I have some other bins I am going to compare later. Overall, I have these bins:
BKMN - 5.7L TBI (This is the MEMCAL I am using with the jumper wire)
BHDC - 7.4L TBI
BJLH - 5.7L TBI
BJLF - ???
BNBJ - 4.3L CPI
BJXA - ???

Engine setup:
stock GM Goodwrench 350 low miles
1986 TPI base, runners, plenum
1995 LT1 throttle body, TB gasket, 24#/hr injectors (cleaned & flowed)
4-speed trans (SM465)
mechanical fan

One other thing I found was that the wiring for LT1 IAC to the 427 ECM was correct using the 1994 - 95 truck wiring diagram in terms of colors. The enigne idles at 550 RPM and the IAC corrects properly (+/- 25 RPM). It just has this odd slight lope that I think is from using the TBI fuel mode.

I need to look at the code some more because I thought that adding the MEMCAL jumper wire would cause the injectors to fire every 4th DRP (double fire). I still don't have a great understanding of the fuel code and how the TBI fuel mode works with the MEMCAL jumper because it still seems rich with the correct injector constant, #cyls, and I reduced the idle VE by 10%.

 

The TBI fuel mode works just as it did in the old TBI ECMs. The injector drivers are controlled at the hardware level. All the PCM does is write a pulsewidth to the hardware address used in TBI mode, and itd outputted at the injectors. The firing rate and order is controlled at the hardware level from whats in the code.

The MPFI portion are the TOC 4/5 interrupt lines tied to the injector drivers. The software sets when the interrupts will occur and whether the TOC line will be high (injector energized) or low (injector de-energized). The memcal controls a counter/flag in the code that tells the code when it needs to fire the injector and which injector/injector bank should fire. The memcal isnt necessary to fire the injectors in MPFI as they are entirely software controlled and can be set arbitrarily. The memcal probably just provides an easy way to control the firings based on the model of truck that the PCM will be used in.

 

That is what I thought. So when I installed a jumper wire in the MEMCAL it was to change to "inject every 4th DRP" or double fire batch mode. So the ECM writes the BPW to the injector driver hardware and the hardware turns on/off the injector every 4th DRP, correct? This is all done using sync fueling, correct? Sorry for the TBI ignorance...this is my first time messing with it.

That is true it is the software that controls the injector drivers, but the software reads 0x3FFA and checks bit_6 to see if it is time to fire the injectors. I think the bit_6 toggle rate is set by the MEMCAL which I set to "inj. every 4th DRP" with a jumper wire.

That is why I don't understand why TBI mode or CPI mode (0x400B bit_0) should make a difference in my case. I have the jumper wire in the MEMCAL so I would think that the BPW should be the same for each case. Confused..........

 

For whatever reason, GM chose to have the TBI and CPI/MPFI injector driver circuitry be seperate hardware. The only thing they seem to share is the fact that theyre both tied to the switching transistors for the injectors. Other than that, they are seperate and distinct. The TBI injector driver is autonomous and just needs a pulsewidth. It fires in the typical alt. TBI firings. The CPI/MPFI uses the TOC 4/5, which as you said, is triggered by the flipping of that bit with the rate set by the memcal. I think they can both operate at the same time, so if your not writing to the TBI driver, it doesnt really matter in the end, but the TBI mode bars updates to the CPI/MPFI injector drivers when active and vice-versa.

 

.

 

It looks to me like it checks 0x3FFA_bit6 and then checks if 4 DPRs occurred using 0x0829. Then it does a BPW check to determine if the TOC4/5 setup should occur to fire the injector. That is, it checks to see if it should fire using single fire sync, double fire sync, or async.

The 1x cam sensor thing kind of messes me up still with the ASDF thing at 0x400C_bit3. It looks like I always want this bit set to zero or the 1x cam sensor error will occur. I am curious what this bit actual does to the fuel inj. firing.

Even though I can't figure out the fuel strategy just yet...........this TOC4/5 setup is going to work great once I get it figured out and can run the big peak & hold injectors in bank fire at idle and double fire at high RPM.

EDIT: This helped a lot: https://www.thirdgen.org/forums/tbi/...ing-issue.html
TBI appears to use double fire bank. That is, it fires an engine bank of injectors twice per crank revolution. A bank of injectors for TBI is 1 injector. That is 4x the amount of injects for a PFI running in double fire batch mode. A bank of injectors for V8 PFI is 4 injectors.

EXAMPLE:
Engine requires 16ms of fuel for one engine revolution (all 8 cyls fire). The TBI alt. fire will fire INJECTOR_1 four times for 2ms. It will fire INJECTOR_2 four times for 2ms. That is 16ms worth of fuel. By changing the MEMCAL to "inject every fourth DRP" the code will still create 2ms pulsewidths expecting to do TBI alt. fire, but the hardware would only output the inject 2 times during an engine cycle. That is 2/8 of the amount of injects, but since twice the amount of injectors are fired it becomes 2*(2/8) = 1/2. Also, the injectors are bigger (4*24)/60 = 1.6. The amount of fuel is equivalent to (1/2) * 1.6 = .8 of what the TBI setup would have injected.

Should I start a new thread title "ECM 427 / $0D / TPI / MPFI" and link to this thread? I don't want to clog up this thread with sort of non-TBI stuff.

 

I tried all kinds of settings for the AFR MODE words for the fueling after reading the code some more. I have the engine running decent using TBI MODE, but can't get it to start using PFI mode. It seems like I have the 0x400B - 0x400F settings wrong and/or the injector constant wrong for PFI mode. I messed with the "fire all injectors per DRP during crank".

I set the injector constant to 12.10 g/s for both TBI and PFI experiments. It has 4 24#/hr saturated per bank (96 #/hr per bank) that works out to 12.10 grams/sec. That seems in line with the stock 7.7 grams/sec for the 5.7 TBI engine (two 61#/hr injectors).

Anyone have a bin that works with PFI 5.7liter I could take a look at to compare the PFI settings that I did? It would be greatly appreciated.

EDIT: I really think I have the AFR MODE words correct for PFI, but I think that the injector constant is calculated differently when using TBI or PFI mode. I think dimented24x7's XDF has it just for the TBI mode. Something I look into when reading the hac.

 

I dont know if you have this, but heres the latest that I had on the $0D. I dont recall all the details, but I seem to remember there being two PFI modes. One for CPI/MPFI, and one for bank fire with a cam sensor (4 cyl. aps). I think there may also have been option bits to select each, but its been a while since I looked at the code.

 

I downloaded the file using Firefox 2.0.0.16. both the GNU unzip tool and the WinXP built-in unzip tool tell me that the file is corrupt. Any ideas? I would love to take a look at the file. I have read the DRP/start/inject routine over and over again and started adding some comments.

You bring up something that I was going to ask. It appears like there are multiple bits to set.
0x400B_bit0 = TBI / PFI mode
0x400C_bit3 = Async double fire

The 1x cam sensor comes into play when the 0x400B_bit0 bit is set. If 0x400C_bit3 is set then the 1x cam sensor error is checked. Since I don't have a cam sensor then that becomes a problem and the code goes back to a strange TBI mode.

You mention two modes. One for CPI/MPFI and one for bank fire with a 1x cam sensor. I need to figure out where they are because I only see one PFI mode that can be sync or async. It looks to me that the sync mode depends on the cam sensor, but I think that is the mode I want. The other CPI/MPFI appears to be async..............or maybe I am just confusing sync in the sense that it is not saying sync to the DRP and means sync to the 1x cam sensor.

Thank you for the info. I will see what I can come up with when reading the code tonight.

EDIT: I think I understand the PFI modes. Doing the MEMCAL jumper wire and setting 0x400B_bit0 = 0 will do a PFI batch fire mode. This is what I am running right now. This mode fires all 8 injectors every 4th DRP and can switch between single fire sync, double fire sync, async single fire, and async double fire. There is also a PFI mode that can do bank fire which is when 0x400B_bit0 = 1, but this also uses the 1x cam sensor. This is the mode I want so I will need to do some more investigating because of the 1x cam sensor error (maybe just turn it off with the Err 41 mask.
The injector constant is the same for all modes (PFI or TBI). It is represented at a "per bank injector" constant. The cloud is starting to clear.
BNKM - 5.7L TBI, 4L80E, 1995 (This is the MEMCAL I am using with the jumper wire)
BHDC - 7.4L TBI
BJLH - 5.7L TBI
BJLF - 5.7L TBI
BNBJ - 4.3L CPI
BJXA - 4.3L CPI

 

Progress.........
Finally blew the dust off the ECM testbench and tried out the BNBJ bin to see why it wouldn't start the engine. With the certain set of bits I had checked for the AFR MODE words it would stop firing the injectors and set the DRP error bit. After playing with the MODE settings, injector setup, and more code commenting........it finally clicked. It runs using the TOC4 / TOC5 injector firing scheme. Thanks to all that helped figuring out the mode setup.

One strange this about the CPI code is that the spark ref goes negative with the stock settings. I used the TBI spark settings and tweaked them for the application (lower compression, cam, etc)

 

I did a bin CAL compare between the BDWM and BNBJ. The BDWM CAL is closer to my setup. If I used the BNBJ then all it would have going for it is the fuel injector stuff which most isn't good for a saturated PFI injector. The EGR and spark tables in the BDWM are better. The MAT tables needed tweaks.

If you set the CPI mode bit and turn off "fire all injectors each DRP" then the code simply returns from the DRP routine and does not fire the injectors. This was also verified on the bench. Maybe you are cranking fast enough to transition into crank-to-run mode and that is why the injectors fire and the engine starts.
You must have some major tweaks in that BNBJ base for spark timing because it is way off from what a normal V8 PFI batch fire would use.

After reading and adding some new comments to the $0D code here is what I found:

TBI mode does async/sync and always uses hardware for injector firing. The MEMCAL sets the rate at which to fire the injectors and which bank(s) is fired.

CPI mode without ASDF set does sync double/single fire and always uses software (TOC4/5) to ALWAYS BATCH fire the injectors. This mode uses the hardware to do async injector firing when needed (TPS AE, etc).

CPI mode WITH ASDF set does sync double/single fire and always uses software (TOC4/5) to ALWAYS BANK fire the injectors. This mode uses the hardware to do async injector firing when needed (TPS AE, etc). This mode uses the 1x cam sensor. If the sensor is in error it stops using software firing and uses hardware firing like TBI mode.

Now it is time to tweak the code to use the CPI mode with ASDF and remove the 1x cam sensor error check. This will allow alternate bank fire at low BPWs and switch to double fire batch at higher BPWs. It will make it possible to drop in the 72 #/hr peak & hold PFI in the LT1 intake and have it idle well and make some HP.

 

Fast355,
Have you verified that you are actually using the CPI mode (software fires injectors) using the bits from address L003F?

From you CPI setup description I think you have stuff set to CPI mode, but TBI mode is being used because of errors in your settings for CPI mode. Since you have the MEMCAL jumper wire installed then it will do sync batch fire just like the 730 ECM. That is, you wouldn't know the difference between CPI and TBI mode with your MEMCAL jumper wire.

The only way to verify that a true CPI software fired injector scheme is being used is to modify the code to report L003F or another CPI specific address for CPI fueling. Address L0051 is reported to the ALDL in stock form but is used for both TBI and CPI fuel modes.

 

Another interesting thing I found with the $0D code is that it will do a negative spark advance value and send it to the ALDL. TunerPro can't handle signed values so it treats a 2's complement number as signed and displays the wrong value.

 

oopppsss.....wasted space

 

Well I gotta say that dimented24x7's hac has been a MAJOR help in figuring out the fuel modes and the fuel constants and tables. The TBI_to_TPI.doc posted earlier has some bad values in it. The offset correction and battery tables are only half. The min. BPWs are on the large side. After a few weeks of reading and commenting the code, it actually runs decent now using the CPI software injection mode. Now on to fixing up the timing stuff.....strange how TunerPro can't handle 2's complement numbers (signed numbers).

Oh yeah, the XDF file has the wrong equation for calculating the fuel injector constant. It is missing the DRP scaling........which works out fine for the TBI fuel injectors because the DRP scaling is 1 in that case.

 

Started adding code for boost. Here is a little patch for reading in ECM Pin B6 that is currently unused by all of the 427 ECM masks. The ".if" statement if for a conditional assemble so you can ignore that part.

;; Read the 3_bar MAP sensor at pin B6 -> AN0 (sync MAP reads)
.if MAP_3BAR_ENABLED
LDAA #0x00 ;0000 0000, A/D channel 0 (channel AN0)
STAA L3030 ;A/D control reg
ASLD ;33 cycle delay for A/D channel conv.
MUL ;
MUL ;
MUL ;
LDAA L3031 ;Get A/D MAP
STAA L02FD ;Save it, A/D 3_bar MAP val.
.endif

 

Cool to hear your making progress with getting the PCM to work with MPFI.

For the boost code, do you plan on having it be supplimental for the fueling/spark, or are you planning on maybe reworking the code to handle boost overall?

 

Not sure what you mean, but I did the following:
1) read in and condition the 3_bar MAP sensor input
2) check RPM, 1_bar MAP, and 3_bar MAP quals for entering boost
3) create MAP AE var. for boost
4) do 3D lookup for BPW multiplier
5) do 3D lookup for spark subractor
6) apply VE value to BPW and remove spark
7) adjust stock CAL slightly for boost

That is all that is required. The stock CAL will take care of pretty much everything you need under boost conditions. That is, when it enters PE MODE it shuts down stuff.

 

Ok. I see. Any thoughts on using a full 0-300 kPa VE table?

I think for the stock code the only major thing you'll need to do is disable teh pseudo-baro routine so the baro doesnt get stuck at 105 kPa after WOT.

 

You can do a 0-300 KPA table, but the resolution between KPA can be a min. of (300-0)/16 = 18.75 KPA (2.7 PSI under boost) per entry. That is rather poor resolution. I break up the MAP and linearize it using more tables and therefore better table resolution. With the BAUJP code I use a 2-bar GM MAP sensor and use a NA VE table (20 - 104 KPA) and a boost VE table (104 - 208 KPA). The NA VE is up to 6400 RPM with stock MAP spacing. The boost VE table is larger at 17x17.

With the $0D code I wanted to revisit some of the 3_bar sensor stuff I messed with during the BAUJP build. I have a few 3_bar sensors and a bunch of 1_bar sensors sitting around. The great thing about the 3_bar sensors I have is that they are from diesel apps. Therefore, they don't read vacuum all the way down to 0 KPA. They only go to 51 KPA at A/D value 0. From A/D = 53 to 255 they read boost (up to 3_bar). A GM MAP 3_bar will read vacuum and has less boost resolution than the diesel 3_bar. So I get the best of both worlds............1_bar that is accurate with good resolution to 10 KPA and a 3_bar that is accurate with good resolution to 3_bar. The downfall is the complication of an extra sensor.

Yes, low TPS and boost can confuse the stock MAP code. I haven't seen the WOT problem. I think I remember it being disabled at WOT. I will look again tonight.

 

I would so much rather have an extra sensor than less resolution. I've always wondered why the code59 and megasquirt guys dont run multiple sensors.

 

Regarding this post, I've noticed that in BCC BHRJ 4.3L CPI bin, the injector constant in Tunercat is 39.8 #/hr. That's only enough fuel for roughly 135 horsepower and I find it hard to believe a 4.3 Vortec V6 only makes 135 HP. From reading this post and others before it I gather that the injector constant "scaling" is missing here. Mind explaining the scaling in more detail? I would think the true HP for such an engine would be closer to 200 HP. That would mean the injector constant should be 58.8 #/hr which is approx. 1.5 times the listed injector constant. Is this the DRP scaling you mention for the injector constant for a V6 and would that mean a V8 scaling factor would be 2. I've noticed that BCC BKCP 4 cyl. MPFI has injector constant of 34.5 #/hr. This equates to roughly 117 HP which is reasonable for a 4 cylinder. So the DRP scaling factor here would be 1. So for a V8 with 4 22#/hr injectors the injector constant should be 4x22=88 / 2 = 44? I meant V8 MPFI not TBI.

 

The vortec V6's actually made around 210 HP stock. Keep in mind that they also used the CPI injectors, which on these PCMs had a different firing rate than the TBI injectors, which fired one injector per intake cycle. I'd have to do some research to remember the details, but the injector constant there probably isn't indicative of what the true flowrate is due to the way the fuel calcs are set up. IIRC, the poppets flowed something like 19 PPH each, with a single low Z TBI type injector valve at the center controlling the flow of fuel to the poppets.