MR_Loyale Posted January 4, 2017 Share Posted January 4, 2017 I have also found that pins 9 & 10 [2 of the 3 mode select pins] on the CPU have 100nF capacitors to GND. Reset Has a 10nF. Those 2 will be low longer than reset. Not sure if it would be long enough for it to read them as low at power up, but maybe? That is quite possible. Because the state of those pins is latched in during reset and loaded into the program counter it could be we are not in mode7? Is that what you are thinking? Quote Link to comment Share on other sites More sharing options...
MR_Loyale Posted January 4, 2017 Share Posted January 4, 2017 (edited) Once these maps are available, would they be compatible with the n/a "spider intake" xt ecu? I kinda doubt it, as that engine has an optical distributor. Not the reluctor setup the loyale used Well if the EPROM data that DaveT downloaded with is reader are indeed maps, they are all ready available a few posts up. Feel free to download and go take a look. Exploring will be easier if you get the hex editor to navigate the file. Edited January 4, 2017 by MR_Loyale Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 4, 2017 Author Share Posted January 4, 2017 In a general way for now, the ecu knows the rpm, airflow, throttle position, and pulse from the distributor, and fires the coil. Some combo of math and look up table would adjust the delay = advance / retard. 1 Quote Link to comment Share on other sites More sharing options...
[HTi]Johnson Posted January 4, 2017 Share Posted January 4, 2017 Oh man. Very interesting. Following this. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 5, 2017 Author Share Posted January 5, 2017 It looks like the CPU is in mode 1, if my thinking about the capacitors is correct. But this doesn't match the table 3 in the CPU data sheet, because the address and data are multiplexed from what I have traced so far. According to the wiring traced so far, it's mode 0,2,4, or 6. I can capture the state of those pins once we have determined all the GND & power wiring and I can power the thing up. Getting the logic analyzer close to the car is not very practical. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 5, 2017 Author Share Posted January 5, 2017 Traced out some of the power supply. +5V to run the CPU comes from the C of T1, the big transistor on it's own heat sink. IC10, the HA1835 is the regulator that drives T1, a 2SB566A PNP Bipolar transistor. Found the switched 12V input to the regulator. Still have to find the constant power feed. Quote Link to comment Share on other sites More sharing options...
MR_Loyale Posted January 5, 2017 Share Posted January 5, 2017 It looks like the CPU is in mode 1, if my thinking about the capacitors is correct. But this doesn't match the table 3 in the CPU data sheet, because the address and data are multiplexed from what I have traced so far. According to the wiring traced so far, it's mode 0,2,4, or 6. I can capture the state of those pins once we have determined all the GND & power wiring and I can power the thing up. Getting the logic analyzer close to the car is not very practical. Do you have access to any schematic software? If we could be a preliminary schematic going, it would help to better visualize this. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 5, 2017 Author Share Posted January 5, 2017 I have cadstar, the pro software I use at work. I have to build all of the unique chips (any parts I used previously, I already have) for it before I can start drawing a schematic, so I've just been writing it out on paper, or just making notes. Quote Link to comment Share on other sites More sharing options...
robm Posted January 5, 2017 Share Posted January 5, 2017 Regarding the ignition timing: Since the CPU can't anticipate an event, it can only react, the ignition trigger must occur well before TDC. Then the CPU computes a time delay to fire the spark some time later, that will wind up being at 20 BTDC, or whatever is on the table or calculated. I have always assumed the static, at idle ignition timing was the basepoint that the CPU used to calculate the timing at other RPM's and loads, but I suspect that is not the case, now. Especially since my current Loyale was set to 30 deg, BTDC at idle, and never really exhibited any of the expected signs of too much advance when running at speed. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 8, 2017 Author Share Posted January 8, 2017 I did some more tracing to locate the always on part of the power supply. Starting to get the idea that there are 2 different versions / wiring pinouts for ECUs, between older GLs and Loyales possibly. Quote Link to comment Share on other sites More sharing options...
MR_Loyale Posted January 11, 2017 Share Posted January 11, 2017 Do you have a Loyale ECU? Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 11, 2017 Author Share Posted January 11, 2017 Yes. I have those also. I have to lay out a couple of harnesses to help trace out the power wiring. As much detail as there is in my 2 FSM s, they don't bother to clearly indicate which connector each of the wires is in. Quote Link to comment Share on other sites More sharing options...
MR_Loyale Posted January 15, 2017 Share Posted January 15, 2017 Did you ever get the cpu desoldered? Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 15, 2017 Author Share Posted January 15, 2017 I was thinking of getting the power wiring figured out, so I can capture the state of those mode select pins first. I will spend some time on this today. If it looks like the mode uses internal code, pulling the cpu is next. Quote Link to comment Share on other sites More sharing options...
skishop69 Posted January 15, 2017 Share Posted January 15, 2017 I haven't had a chance to review the BIN yet. A week before last Tuesday, the roof blew off my deck so I've been dealing with damage control and the insurance. It used to be attached to the the deck and the roof on the second story of the house in the back. Tuesday morning, it was in the front yard laying against the house. May not sound too bad, but this was a 20'x30' all steel roof weighing in at 2000 lbs. Had to bring in a crane to get it off the house and dismantle it. Happy New Year to me. Quote Link to comment Share on other sites More sharing options...
Crazyeights Posted January 15, 2017 Share Posted January 15, 2017 Glad you are ok I hope ? Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 16, 2017 Author Share Posted January 16, 2017 Here is a list of ECU part numbers and cars they came from / are in. Looking for patterns, and more data from any other out there, if you can read yours and add them, that would be good. GL / Loyale SPFI ECU numbers / versions. Assuming 49 state unless marked otherwise. 1987 2WD 3AT wagon [4WD added] 2261 AA200 MECF – 011 7122 3E Big letter to the left = N Painted ECU 1988 4WD 3AT wagon 2261 AA390 MECF – 021 7805 3C Big letter to the left = 18 Painted ECU 19?? 4WD ?? wagon 2261 AA100 MECF – 001 5Y14 Big letter to the left = E Painted ECU & flatter case 19?? 4WD ?? wagon 2261 AA102 MECF – 002B 6429 Big letter to the left = R Painted ECU & flatter case 1990 4WD 3AT wagon – not 100% sure, just by process of elimination 2261 AA394 MECF – 023 9Y27 G5 Big letter to the left = A9 Gray ECU 1992 4WD 3AT wagon 2261 AA395 MECF – 025 1X03 H7 Big letter to the left = J4 Gray ECU 1993 4WD 3AT wagon - California market 2261 AA395 MECF – 025 2622 H7 Big letter to the left = J4 Gray ECU I have one from a 1987 4WD 5spd d/r wagon, one of the unknown ones.I have one from a scrap yard, probably a wagon, don't remember. I may have another floating around that I can't locate right now. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 16, 2017 Author Share Posted January 16, 2017 (edited) I took a look in one of the know ECUs the 88 - Quite different from the one I started with. I'll add more info about that tomorrow.Hopefully, we can identify what cars the flatter ones came from, as they don't seem to match the others. Edited January 16, 2017 by DaveT Quote Link to comment Share on other sites More sharing options...
MR_Loyale Posted January 16, 2017 Share Posted January 16, 2017 I haven't had a chance to review the BIN yet. A week before last Tuesday, the roof blew off my deck so I've been dealing with damage control and the insurance. It used to be attached to the the deck and the roof on the second story of the house in the back. Tuesday morning, it was in the front yard laying against the house. May not sound too bad, but this was a 20'x30' all steel roof weighing in at 2000 lbs. Had to bring in a crane to get it off the house and dismantle it. Happy New Year to me. Yikes! You concentrate on your roof. We will still be here. Quote Link to comment Share on other sites More sharing options...
DaveT Posted January 16, 2017 Author Share Posted January 16, 2017 Oh, the ECU numbers are all visible on a label located in the center of its cover. Just have to remove the plastic panel, and look. I've never reinstalled that panel.... Quote Link to comment Share on other sites More sharing options...
DaveT Posted February 1, 2017 Author Share Posted February 1, 2017 I have a couple of special effects builds eating my time right now, but will get back to this research. I was hoping for a few more ECU nameplate info with model & year to help decide which ECU to re-start tracing, since I inadvertently picked an odd one to start with. Since there are at least a few differences in the ECUs, when I get back into it, should I restart on this thread, or start a new one? Quote Link to comment Share on other sites More sharing options...
MR_Loyale Posted February 1, 2017 Share Posted February 1, 2017 Sorry, I too have been distracted with witk. I have two ecu's I can get numbers from. Let's keep thus thread so it is all together. I did find some info online about building ssm interface hardware. I ordered the connector but haven't had time to do much more. Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted November 21, 2017 Share Posted November 21, 2017 Has anyone reached out to Rob, or RobTune fame over on Legacy Central? Seems like he did all this decoding for the EJ20G ECUs and might be able to provide some guidance and a heap of experience on this matter. It would be really cool to be able to rechip, or even reflash an EA82T ECU. Quote Link to comment Share on other sites More sharing options...
DaveT Posted November 21, 2017 Author Share Posted November 21, 2017 I'm pretty sure flash memory did not exist back then. More likely any ROM is either one time programmable or UV erasable. Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted November 21, 2017 Share Posted November 21, 2017 I was suggesting Rob's expertise not because I thought the two control systems were very similar, only because, as I understand it, he basically single-handedly decoded and modified the EJ20G ECU code. That experience could prove helpful on your quest. Quote Link to comment Share on other sites More sharing options...
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