James' Civic Rebuild Thread + High Power ER Motor Theory

[James]

Oh yeah, on another note I have been doing quite a lot of reverse engineering of the factory city ECU, I tihnk I might have a decent play with tuning it before I change to OBD1

[3GCVC]

from what motor do you think is the best ECU and dizzy to run the OBDO and 1 Respectively? i have found an adaptor for my motor.

If you want to run OBD0 then you need the ECU and dizzy from a b16a da6 I think. If you want to run OBD1 then it doesn't really matter, they all have the same plugs and pretty much the same dizzies.

What do you mean an adaptor for your motor? Does it go from the EW-5 ECU plugs to OBD-1 ones or something? If thats the case then its probably an OBD0 VTEC to OBD1 boomslang harness. In which case you would have to shuffle pins around in the factory plugs on your loom and add a few extra.

i mean i found an adaptor to put the newer series dizzys onto my motor like D16A6 or D16Y8, im sure others would have to fit as well, would still have to figure out the wiring as well thats the hard part.

[James]

I just found out a mate has a cheap OBD0 B16A ecu in his garage (PR3) and hes bringing it to work tomorrow. I tihnk I will use that instead as it will make wiring easier.

[ProT]

Is this any help to the people out there?

http://www.hondatech.com.au/forum/showthread.php?t=105

[James]

Thanks for that link ProT, if you have a look at the first pic in that thread, see how familiar the ECU on the bottom looks?

I got my OBD0 PR3 today. I desoldered the chip first thing, so I can put a socket in it.

Next I started comparing the wiring between city turbo and da6 integra, and so far they are pretty much identical, we are talking plug and play! So this is looking pretty sweet. I will just have to build a little CVCC driver board that can tuck in the ECU somewhere, conveniently the pin that normally powers the CVCC injector int he city ECU is just not connected in the PR3 so I can tap onto it :D Happiness!

Just have to work out how to get the dizzy on next, then I can start playing!

[James]

OK So im pretty much done comparing the city turbo ECU Pinout to the PR3 pinout, here is a summary. It was a real pain that between the City Trubo and the PR3, although they kept a lot of the same pinout, and exactly the same plugs they completely changed their numbering scheme, hence the random numbers matching up down the left hand columns.



As you can see its pretty damn good, there are only a few additions required and most if not all of them are for programmable ignition, which is definately worth it!

As a side effect of doing this I now have a mostly translated ECU wiring diagram. The image is freakin huge so Ive changed it to a link.

http://i7.photobucket.com/albums/y295/bigelboe/Custom%20ECU/16big.jpg

Few things left to do, find an ECU wiring diagram for a T2 so I can work out what the strange Injector signals go to, and also work out what a few of the PR3 sensors are, like the EACV. All in all I am rpetty happy

[James]

I've translated more of the ECU wiring diagram and added most wire colours. Ive also started translating a T2 wiring diagram. I had a look at my wiring diagram and its a bit of a mess, my plan at the moment is to get a b16 wiring loom, cut and lengthen everything to fit nicely and then do an adaptor loom back to a city turbo ECU.

If anyone is interested in helping me, and has a spare T2 ECU to trace and has a knowledge of electronics let me know Long shot I know

Also had a look at installing the dizzy today. Its looking pretty good. I will have to cut two of the 3 legs off the dizzy in order for it to fit, and add a leg on the thermostat housing but thats about it, fairly basic really when I was considering I might have to modify all the coolant side of the thermostat housing.

[James]

Finally got my ROM programmer today, downlaoded the T1 and T2 ROM's to my computer and started work on understanding how the T1 ROM works of which I have made substantial progress quite quickly. I now know which parts of the program deal with outputting the error codes, have found all 5 maps and have worked out that a timer gets set to produce a 100Hz square wave. I may start a new thread to document my findings all in one place, might provide an interesting read for someone too I guess.

Im starting on the T1 ROM because its about 1/3 the size of the T2 ROM

[James]

Been working fairly consitently on understanding the T2 ROM, and tonight I just had a breakthrough...

I found FULL bi-directional datalogging support built right into the T2 ECU. I knew it had the hardware for it, but I just found the software. It appears from first glance it outputs a trigger signal, which you respond to with your data request, which it loads and then sends you different data depending on which set you asked for. This is extremely cool stuff and could make for some very cool gadgets and stuff for T2's!

[Hyperblade]

Been working fairly consitently on understanding the T2 ROM, and tonight I just had a breakthrough...

I found FULL bi-directional datalogging support built right into the T2 ECU. I knew it had the hardware for it, but I just found the software. It appears from first glance it outputs a trigger signal, which you respond to with your data request, which it loads and then sends you different data depending on which set you asked for. This is extremely cool stuff and could make for some very cool gadgets and stuff for T2's!

Wooooo awesome stuff! Well done!

[James]

Have done some more work on the datalogging, the ECU sends out 44H as a start command and checks to see if anything replys, if it does it checks this reply to see what mode it will work in for that datalogging session.

Seems there are 6 modes. 4 of them involve the ECU sending the data from various RAM locations out the logging port, with each mode sending a different combination. And the other two are for writing stuff from the datalogging port to the ECU, not sure what this is for, perhaps the tune can be modified on the fly or something?!?!

On a stock T2 the code is completely skipped as there is no reply when it sends the initiation command to the logging port. The list of memory addresses it sends is quite helpful to me as the ones common to all 4 lists must be important ones like MAP value or REVs.

[James]

I just purchased an LSD out of a D series honda gearbox Will take some pics and explain my plans when I get it

[BOOSTBOY]

bigelboe - great work with all this, even though i havent owned a City Turbo for a very long time, i still follow with interest - well done mate!

Glenn

[James]

Cheers Glenn, good to see my novel is keeping someone interested!

Ive been doing yet more work on the T2 ROM, I think I have found the bit where it actually reads the fuel maps from the ROM and does the interpolation, however the 16 bit maths is a real pig to follow in assembly, Ill paste a bit here just to show everyone what Im dealing with.

MOV D,A ; D = Hmod + (L x 4)
MOV L,A ; L = Hmod + (L x 4)
MVI H,80H ; H = 80H
MOV A,M ; A = data at 80(Hmod + (L x 4))
STAX B ; Send data out
INX H ; 16 bit number
MOV A,M
STAX B ; Send second byte out
MOV L,E
MOV A,M ; 80(Lmod + (E x 4))
STAX B
INX H ; 16 bit number

L0016: MOV M,A ; Erase the 5114 Bank 0 RAM except for 9000-900D (rest from above)
INX H
DCR B
JNZ L0016
MVI A,02H
STA 9015H ; Store 2h in 9015 RAM
MVI A,0C4H
OUT 84H ; Setting the 8155 Internal Counter Low Byte
MVI A,49H
OUT 85H ; Load timer with 2500d, set as square wave generator.Running off CLK/12 0.01s period
MVI A,0CDH ; Set PA as output, PB as input, PC as output, start timer, disable interrupts
OUT 80H ; Setting the 8155 Internal Control Register
LDA 8052H ; Load the output mask from before, likely zero, might be stuff.
OUT 81H
MVI B,1EH ; B = 1Eh
LDA 806CH ; 14h intially

All the stuff after the semi-colons ( ; ) is comments I have added once I tihnk I know what that instruction does.

Yeah like 6-7000 lines of that is what controls your car

[Hyperblade]

I'm reading every word, and keeping a close eye on how your progressing, keep up the good work!