ALDL Cable Questions

[nocooler]

So my neighbor has an 86 Corvette. He's not looking to go fast but is tired of it being a complete slug. He has a new chip for it, probably a hypertech or jet. The guy he's been going to for work wants 6 hours of labor to change the chip, said the whole dash has to come out. It looks like its up there a ways but it's all supposed to be accessible from the bottom. I told him we could do it one afternoon in the spring but I'd like to at least scan it first, hence the need for an aldl cable and they aren't cheap anymore.
From what understand the 86 it has a '165 ecm and will communicate at 160 baud on "E" pin or 8192 baud on "M" pin. I've seen a few schematics and the TPI stuff needs a 10k resistor across "A" and "B" to put the computer in diagnostic mode. The high speed data set seems like it'll be useful. I've been looking over wiring schematics and some are simple, while others are more complex.
http://winaldl.joby.se/aldlcable.htm
https://www.thirdgen.org/forums/diy-prom/275994-making-my-own-aldl.html
https://www.techedge.com.au/vehicle/aldl8192/8192hw.htm
http://aldlcable.com/instructions/ALDLbareINST.pdf
Does anyone have any ALDL brain cells left? The last link makes it seem like you can just grab data straight off the "M" pin. While a couple others show max232 chip or some other parts to make some magic happen. Can I just use the simple transistor or do I need to go with the max232 chip?
Thanks

[earlbrown]

I did a production run of ALDL cables about 13 years ago and I think I have a few left.


Going by memory, I used a transistor, at least one resistor (maybe two) and I included a cut loop sticking out of the DB9 connector.     The instructions I used at the time said that some cars needed one wiring, and others needed different circuit.   I have no idea if anybody had to cut the loop but I never heard that anyone did.   Seems like the loop needed a ground on that scenario, I'd have to look at the instructions I made in the box 'o cables.

There's also a 'how to' I wrote on turbobuicks.co m way back when.

   Talk about a blast from the past. I actually bought the parts at retail over the counter at Radio Shack.    Those days are long gone!

[nocooler]

Thanks Earl - I thought it was you who made some years back - I'll try to find the link on tbs.com
If you have one - let me know the cost.

[nocooler]

Adding these links for future reference
https://www.turbobuicks.com/forums/buick-v6-turbo-tech/54782-how-setup-winaldl-scan-your-car.html
http://couleefiero.tripod.com/ALDL.htm

[daveismissing]

If you dig up the description of the ECM stream many( at least some) of the fields should match the scanmaster stream  IIRC ( but then you probably don't have one anymore)

[daveismissing]

6 hrs of labour would make a bluetooth adapter and ALDLDroid look very inexpensive

[earlbrown]

I was thinking it was '06. That post was a couple of months after my car got stolen and I was scanning my old boss' ''upgraded'' GN.

  Pretty sure I have some of the pretty blue ones in my nudie book room under a box of bottle tops.

[earlbrown]

I finally got around to digging through the archives.   ...and found a motherload in the room I don't use!  lol


Found some Russian idler pulley bearings, an Autometer mechanical oil gauge, and old old old school AMS boost controller, one ALDL cable I built, a bunch of USB to DB9 adaptators, and a very old scan tool with a 3.5" floppy and a PRINTER PORT adapter that Zap sold to Jim Seaton.

That room has all my old catalogs from the 90's too.   Didn't go that far back for fear of not making it out alive.   (man there's a lot of pr0n in this house )

[nocooler]

Alright, small update - my neighbor ordered the usb/aldl cable and we hooked it up today.

There are a handful of codes the ones that need to be addressed are 36 - maf burnoff circuit and 45 - o2 rich
TPS volts is low .29v @ idle - needs to be bumped to .54v
BLM and INT are both on the low side so it's pulling fuel. o2 is lazy.
I'll need to diagnose the burnoff circuit in the MAF - it could be the relay or MAF
O2 looks like it's been there awhile so I'll probably put a denso in it. 

[nocooler]

Swapped out the oxygen sensor today and reset ecm. I went to adjust the TPS, and it is dead - it will swing from .5-1.65v and sometimes it will hit 2.xx volts. The car cycles from rich/lean in closed-loop now and has a little burble out the exhaust now that it's not drowning in fuel. He took it for a cruise and couldn't believe what a difference a $7.99 part makes. 

Next up - throttle position sensor swap.