What If? $8D (1227727 ECM) for TBI

[ralmo94]

The 1990 Chevy Lumina 2.5 Liter is listed as 1227727 TBI with DIS. The injectors appear to be similar to the injectors used by the Holley TBI.

My research shows the 1990 Lumina 4 cylinder is chip AUAJ, but I don't know the mask.

Im quite certain the s_$8d code will run in the ECU I have purchased, and was about 99% sure of the TBi path with it, until reading this thread all the way through where it is reported that the 7727 might be missing the sense resistor to use peak and hold as was stated here, unless I'm misunderstanding

Looking at the schematic, it *could* be done but it looks like the 44 pin PLCC that has the injector driver logic is missing. So if you felt like soldering down U15 (and the other parts) you could make it work. But that U15 kinda throws a wrench in the works

Not sure if Dynamic EFI is in the budget but it is a good option. Single TBI unit on a 4-cylinder engine. http://dynamicefi.com/EBL_P4_Flash.php]

With that budget I would probably fashion a crank trigger and attempt 0411 4cyl. I don't mind swapping chips.


The link for injector driver info is good, but it doesn't clarify what ECU's have the hardware to support TBi mode.

[ralmo94]

The 1990 Chevy Lumina 2.5 Liter is listed as 1227727 TBI with DIS. The injectors appear to be similar to the injectors used by the Holley TBI.

My research shows the 1990 Lumina 4 cylinder is chip AUAJ, but I don't know the mask.

A quick look at rockauto confirms this, ECU is 727, and a TBi injector. Says plug and play for ECU with original prom. This is looking more promising, just hoping the 9396 also has the injector sence circuit needed? I might need to wait until I get home to open the case and confirm, but not sure what I would be looking at.

[ralmo94]

Looking more at the pcm hacking site
https://pcmhacking.net/ludis/1227749schematic.html
Seems to show u15,
That was the item in question to make the jumper functional, correct?
Screenshot_20221022-194948~2.png

[ralmo94]

Looking closer at the schematic I posted a screenshot of, it looks like it has 2 inj sense circuits,
U13 & u15, would this be a viable alternating 2 injector TBi ECU? If I'm understanding everything in this thread and schematics from 20+ years ago is correct I think so.

[dave w]

The attached documents might be interesting / helpful?

[ralmo94]

The attached documents might be interesting / helpful?

Valuable information for sure. Any reason the pinout diagram is not on the 727 information page?
Also on the 9396 information page it seems that just like the 727 9396 only has 1 injector driver. Capable of being peak and hold.
Seems like ike it wouldn't be cheap enough to add another driver on the board from that pdf. The 9396 seems to be a lot cheaper to get ahold of than the 727.

[dave w]

Valuable information for sure. Any reason the pinout diagram is not on the 727 information page?
Also on the 9396 information page it seems that just like the 727 9396 only has 1 injector driver. Capable of being peak and hold.
Seems like ike it wouldn't be cheap enough to add another driver on the board from that pdf. The 9396 seems to be a lot cheaper to get ahold of than the 727.

It appears definition $89 is for the 1227727 TBI system, which is not available on gearhead-efi.

Perhaps $89 will work with the 8 pin ignition module vs. DIS (crank trigger) with an updated initial spark advance programmed in the chip? I've seen 60 degrees initial spark advance for DIS systems.

It appears datastream A097 is for the 1227727 TBI system, but will it work with the 8 pin ignition module?

Memcal Cylinder Select might be a possible challenge, 8 pin ignition module vs. DIS?

[ralmo94]

I bought a memcal off eBay for a 87 Corsica or Beretta BCC ADDX.
Once I get home look forward to getting the bin off of it. I have no idea if that is $89 or something else.
Might be a couple months.

Most things I looked at before reading this thread show the 8pin HEI and dis module producing the same reference signal to ecu.

I plan on using s_aujp, with my i4 memcal.
S_aujp has documentation for using i4 TBi, but says no one has tried it yet.

[Reiembor]

I bought a memcal off eBay for a 87 Corsica or Beretta BCC ADDX.
Once I get home look forward to getting the bin off of it. I have no idea if that is $89 or something else.

Did you ever figure out the .xdf for the ADDX? I also have one and am trying to find a way to read it.

[ralmo94]

Did you ever figure out the .xdf for the ADDX? I also have one and am trying to find a way to read it.

I still have not got back to pull the bin yet.

But looking at the bcc lookup spreadsheet
http://www.gearhead-efi.com/gearhead...C%20lookup.xls

It shows the mask as 3E.
There does not seem to be a 3E xdf on here. There is however a 4E . Weather or not it would be close enough to develop one, is above my pay grade.

If you have a bin, could you post it?

[Reiembor]

I still have not got back to pull the bin yet.


If you have a bin, could you post it?

Here you go!

[dave w]

ADDX information screen captures below. It appears to me ADDX is definition $3F (Hex address 0008)

1227730 ADXX_01.JPG

1227730 ADXX_02.JPG

1227730 ADXX_03.JPG

[dave w]

ADDX information screen captures below. It appears to me ADDX is definition $3F (Hex address 0008)

1227730 ADXX_01.JPG

1227730 ADXX_02.JPG

1227730 ADXX_03.JPG

Hmm,
Came across a different ADXX.bin showing definition $3E

1227730 ADXX_04.JPG

$3E is available at TunerCats http://tunercat.com/tnr_desc/ecm_sup.html

TunerCats Software $69.95 (includes $42 definition) http://tunercat.com/tnr_desc/sw_dwnload.html
Add $19.95 for definition file $3E


TunerCats is NOT compatiable with TunerPro

TunerCats is Pay-Per-View only . . . and worth every $$.$$ your spend

[Reiembor]

Dave, Everything I had read online referenced the 3e xdf, which I could not find except on Tuner Cat. I also had noticed the same 3f reference when I read the hex file so it made me doubt the 3e information I had seen... But when I load the $3f xdf I found this is what displayed for VE and spark, certainly not right.

tunerProaddx_3f.jpg

Also I come up with a totally different prom ID that you show. What tool are you using to get the PROM info that you screen captured?

I am not opposed to using TunerCat as long as the 3E will really work. Since this bin reads 3F, I am not sure? At some point I will probably take this to S_AUJP, but figured this was the quicker way to get it rolling.

I wonder if the $3F adx I have is a good one? Do you now if there are multiple versions I could check out?

Sorry for all the random comments and questions, a lot of pondering going on here this morning!

[dave w]

Dave, Everything I had read online referenced the 3e xdf, which I could not find except on Tuner Cat. I also had noticed the same 3f reference when I read the hex file so it made me doubt the 3e information I had seen... But when I load the $3f xdf I found this is what displayed for VE and spark, certainly not right.

tunerProaddx_3f.jpg

Also I come up with a totally different prom ID that you show. What tool are you using to get the PROM info that you screen captured?

I am not opposed to using TunerCat as long as the 3E will really work. Since this bin reads 3F, I am not sure? At some point I will probably take this to S_AUJP, but figured this was the quicker way to get it rolling.

I wonder if the $3F adx I have is a good one? Do you now if there are multiple versions I could check out?

Sorry for all the random comments and questions, a lot of pondering going on here this morning!

I used the hex editor from my chip programmer ( https://www.batronix.com/shop/progra...rogrammer.html ) to open the 1227730_addx.bin file.

I'm not sure why there is a hex difference $3E vs. $3F, very odd!

I do not have experience with $3E or $3F, not very common.

My only experience with S-AUJP was a V6 MPFI application, which worked good. At a later date in time the V6 MPFI application was converted to Dynamic EFI which worked better than S-AUJP. In all fairness to both S-AUJP and Dynamic EFI; remote tuning has challenges! The Dynamic EFI system was the better "remote tuning" option.