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

[dave w]

Dave,

Capture both injector outputs with TBI memcal installed. Forget DRP as we know synchronous pulses are tied to it. Do same with 7727/7730 memcal.

As requested. I will do more video later today, to include the TPI chip.

dave w

[1project2many]

Clearly alternating output pulses. After $8D and TPI chip try $8D in TBI memcal.

[RobertISaar]

Clearly alternating output pulses. After $8D and TPI chip try $8D in TBI memcal.

and if i had to guess, i'd say this will be the winner.

[dave w]

Clearly alternating output pulses. After $8D and TPI chip try $8D in TBI memcal.

The "TBI_Chip Injectors-DSCN3746.zip" video file is $8D in the TBI Memcal.

dave w

[1project2many]

and if i had to guess, i'd say this will be the winner.

The "TBI_Chip Injectors-DSCN3746.zip" video file is $8D in the TBI Memcal.

dave w

Yep. You have a winner. No cyl select errors? If not I'd start putting a cal together and planning a test run. Prolly scope the TPI memcal + $8D just to see what happens but the tbi memcal is the path I'd follow first.

[dave w]

Yep. You have a winner. No cyl select errors?

Not a winner with the TBI Memcal! I have an error code 41 (Cylinder Select). I'm sure the $8D definition file is the reason for the code 41. I'm sure there a path forward, definition file, to get the '7727 / ' 7730 to run TBI with a '16197427 TBI Memcal. I also had code 33 (MAP) on both TBI and TPI Memcals.

For the library, see files below:

dave w

[Six_Shooter]

Did you try setting the cyl select in the bin to "TBI" with the TBI MEMCAL?

[dave w]

I had $8D in the chip with the TBI memcal. I am wondering, is there a TBI cylinder select with 8D?

dave w

[dave w]

Did you try setting the cyl select in the bin to "TBI" with the TBI MEMCAL?

Maybe if I set the number of cylinders to V6 "192", I'll be OK?

dave w

[Six_Shooter]

From what I understand, the same cyl select values are used for all (P4) OBD1 ECMs, so you could look at other code to find the hex value for TBI to use it. That was my plan when I thought about using $59 for TBI, I just haven't got around to testing it, and up until recently didn't have an O-scope to verify results with.

[RobertISaar]

^ correct. i think $18 is correct for dual injector TBI? been a while since i've looked at something like that though.

[dave w]

^ correct. i think $18 is correct for dual injector TBI? been a while since i've looked at something like that though.

I'm not quite understanding $18, is that a definition file? I have to deliver this system later today, so I can only get one more test done before it's gone from my test bench! If anyone has a specific test, or maybe a .xdf, .bin, .adx they would like data for I'm very willing to give the test a try.

I'd like to thank everyone for the input I've received on this test!
dave w

[RobertISaar]

i have this in the DTC portion of my A1 XDF. and the comments i entered into the notes box.

$18=TBI
$10=4 CYL PFI
$08=6 CYL PFI
$00=8 CYL PFI

setting that to match your MEMCAL should remove the DTC41 from being set. i have the item listed as "Fuel Delivery Mode (KK41MODE)"

[1project2many]

Cylinder select is also known as "number of cylinders." Robert's suggestion to try changing that to TBI value of $18 is next step.

[RobertISaar]

not 100% certain of how 8D works, but in A1 and it's successors and predecessors, there is the "fueling mode select" and "cylinder count" as seperate items.

cylinder count is simply a multiplier for RPM/airflow/etc calculations, it's the fueling mode select that's used for the DTC41 info.