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

[diver14_98]

bringing this one back from the dead did anyone ever make any headway on this

[dave w]

bringing this one back from the dead did anyone ever make any headway on this

The original idea was to have an underhood TBI ECM. I just recently learned the factory has an underhood TBI ECM, 16184738. At this point in time, there is no support (flash, .xdf, or .adx) for the 16184738 ECM.

dave w

[sailorbob]

anyways, based on GM information(which may or may not be accurate), the idea is that a pulse will happen, time until the next pulse happens is recorded, now the ECM knows engine speed and position. so 2 pulses have happened, now the injectors can start firing. pulse # 0 waiting for pulse 1 start timer 2 end timer, prep for injection/spark, start new timer 3 end timer, inject(either 1/4 or 2/3 depending on 1X signal), start timer 4 end timer, start timer 5 end timer, inject(other cylinder pair), start timer 6 end timer, start timer 7 end timer, inject(cylinder pair injected at pulse 3), start timer

Is this GM information available anywhere? Thanks.

[RobertISaar]

I don't remember where exactly that info came from.

[sailorbob]

Shame, I was hoping it might have helped me get a grasp on the coding they used for the 1x signal and the injectors. The 1x pulse is used in a counter that has values of 0, 1 and 2 and I was trying to figure how that related to the firing of the 4 injectors (fired in pairs) on a 4 cylinder engine.

[1project2many]

I believe I posted the small amount of info we had earlier in this thread. The info was from the Ecmguy webpage, same guy that released the original partial disassemblies of popular gm code many years ago.

[sailorbob]

Now that Geocities has gone I'm not sure how much of the original Ecmguy information has survived. His example hacks have helped quite a bit but the injection code seems to be more like what I see described for Quad4 than those and I haven't found any Quad4 disassemblies.

The workshop manual describes the following injector operation:

Each port injector circuit pulses its two injectors simultaneously once every crankshaft revolution, with half of the fuel necessary for each cylinders combustion delivered by each injector pulse. For minimum fuel supply conditions however, such as idle, a single pulse every two engine revolutions is supplied. The ECM receives an engine speed and crankshaft position signal twice per engine revolution from the ignition module, and uses these to trigger the 'alternate pairs' injector timing sequence. Each injection pulse occurs only when both inlet valves for that pair of cylinders, are closed.

There are two injector circuits on this 01228708 ecu with the injectors paired as 1 & 4 and 2 & 3.

[1project2many]

I'm sure I posted the injector firing strategy. There's a circuit in the memcal that selects the injection mode based on voltage. If you can't find any info in this thread then look for a thread entitled "so you lost your memcal" or something like that. The injector pairing is due to the cylinder firing order. It could be thought of as injector 1 and injector 2 for simplification.

The ECMGuy page got migrated to (I believe) oocities but I believe you'll want good antivirus software before visiting. The info was there at last visit.

[sailorbob]

Thanks. You did post some of the injector firing strategy in this thread but said the details are incomplete. I've looked at your "You lost your Memcal ID???" thread and unfortunately it doesn't help me with figuring out the coding. I'm not sure how complete the oocities webpages are as I couldn't see any info on this subject.

[1project2many]

The code isn't there. What's there is the injector pairing and what should be expected as each reference pulse occurs in terms of injector driver application. Knowing there are several different expected output patterns can help identify switches and code paths as you work through the instructions. Time between reference pulses is a primary variable and is obtained as soon as the engine begins cranking. You'll find it used in several calculations including RPM. There are GM documents and some hacks as well here for several ECM's including $58 used in the 7749. Although $5D uses a newer instruction set, many of the functions found in $58 can be translated to $5D.

[sailorbob]

I think the $8B code may be closest so I'll see if that reveals any clues to me. I can see myself ending up having to put a 'scope on the ignition module to try to see how the injector firing relates to its input and output signals.

[ralmo94]

Bringing this back from the dead again,

I planned on doing a single TBi 4cyl swap with a

16199396

Can anyone confirm if the 9396 actually has the peak and hold components?
https://pcmhacking.net/ludis/p4xref.html#16149396 shows it is the same as 727 with extra ram.
I remember reading that the 727 could be used with TBi with the jumper, and I remember reading it reported that the 9396 will run $8d.

My plan was to run super $8d in TBi as the docs say, and use the 7730 4cyl pinout converted to 727 pin locations.

If my plan is successful I plan to writeup how I did it and what it took.

I have 4 ECU's I purchased off of eBay and a TBi from a 1990 4cyl cavalier.

If it does NOT have the required hardware for Peak & Hold, I might look at finding a 7730 or 727.

The pcm hacking site also shows a 727 being used in a factory 4cyl TBi, BCC, APTW in the W body cars, looking on part store websites and salvage yard searches, I can't find parts for a 4cyl W body, so I don't know how accurate that information is.

Any insight experience or criticism is welcome, and I believe it pertains to the original quest of this thread, an underhood TBi ECU, even though I'm looking for 4cyl single injector.

[dave w]

The 1985 - 86 4-cylinder TBI engines used the 1226864 ECM: http://www.gearhead-efi.com/Fuel-Inj...Information-1C

[ralmo94]

The 1985 - 86 4-cylinder TBI engines used the 1226864 ECM: http://www.gearhead-efi.com/Fuel-Inj...Information-1C

The fiero ECU, but it has card type harness connectors and is not water tight.

Can the 9396 run that mask?

$1c

[dave w]

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.

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

Injector driving information: http://dynamicefi.com/InjectorDriving.php