So after 5 years finally got around to getting some software to see what my '87 is doing.
Have setup Diacom on DOS only computer , but when linking to ECM only stays on "linking" , does not connect.
Engine "SYS' light works
When Diacom in diagnostic mode, fans run so connection is there, but no info.
Where to start?

 

You are supposed to be using a "special" adaptor for the 85-89 TPI's, From what I can tell it is nothing more than the 10k ohm resistor put across pins A&B on the ALDL. This resistor is what gets the ECM ro communicate. If you don't have the adaptor, get a 10k ohm resistor and put it across pins A&B from the back side so you can plug in your Diacom cable from the front and see if that gets it talking.

 

If you're using the Diacom cable system the 10K Ohm will be there when connecting in ALDL mode. The electronics for switching 10K Ohm, 3.9K Ohm or open is in the Diacom cable 91003. If using the Diacom cables, what other cable are you using from 91003 to ALDL? The 91007 (STANDARD) and 91006 (GM SPECIAL-TPI) are wired differently. For '86-'89 TPI cars the 91006 is required as it is getting the data from ALDL pin E (where the 165 ECM High Speed Data is wired). The 91007 takes the data from ALDL pin M. This cable will work for '86-'89 TPI cars, but only in Diacom's DIAGNOSTIC mode and you will only receive the 160 baud data, 1000 RPM, EST advanced, closed loop timers bypassed, yadda, yadda. With the 91006 cable you connect using Diacom's ALDL mode and you will get the 8192 baud data from ALDL pin E. To add even more confusion, Diacom stopped including the 91006 cable in its packages and started using only the 91007 with a little ~2 inch long DIN5 F to DIN5 M that crossed the ALDL data pins so you could get 8192 baud data from '86-'89 TPI cars using the 91007 cable with this adapter.

The other concern is the speed of your DOS only computer and the version of Diacom you are using. The latest version is listed as 2.85 on the Diacom title page (may actually be 2.87, file dated 5/11/2001). This version seems better able to link with faster PCs than did previous versions. If your DOS only PC is pre Pentium, this should not be a concern though. If your BIOS allows minipulation of the parallel port, try changing this starting with Normal and see where that takes you.

Good luck.

 

Hey Ray,
Its nice to know someone over here knows about Diacom. When I eventually get my 87 back together and plug in my diacom+ for the first time, if I can't get it to work, I may call on you for help!!
Same goes for my Pocket Romulator and Pocket Programmer.
I've bought the gear, I just need to do lots of homework to find out how to use it. Come to think of it, I need to do lots of work to get the engine and car back together. So many jobs to do, so little time. I must start prioritising things better
Dave

 

Dave,
No problem, just give me a shout.

 

Great info , thanks.
Am using cable supplied with diacom , has provision for 12V input.
Will check numbers and version and get back.

 

rodj,
As Ray wrote, for an 87 you need the 91003 ALDL lead to your laptop and the 91006 adapter lead to the ALDL connection. The 12v power supply you are referring to (if your diacom equipment is the same as mine) is I think just for the 81 carburetted cars that didn't have power at the ALDL. That is what my instructions say anyhow. You can use the 91007 instead of the 91006, but it will not give you all the proper information and what it does give is at a much slower rate than with the 91006. It uses information from a different pin on the ALDL connection. That is I think what Ray was explaining about with the DIN adapter, unless you use this DIN adapter with the 91007, you will not get a 'full' scan.
Like I have stated previously, I do not profess to being an expert with this, in fact I haven't used mine yet, I just wanted to share what I know (or maybe that should say 'what I think I know') with another novice. It may promote more discussion and we will both learn a bit more.
Dave

 

If you are using a Compaq computer you may need to buy a different scanning software. Compaq configures their ports weird. I couldn't get mine to work and I contacted Diacom 3 seperate times. They sent me updates and everything but no dice!
I went with EASE. It works every time with my Compaq.

John

 

The Forum comes good again.
Thank you gentlemen , now have up and running using "correct" cables.
Funny enough , I am using a POS Compaq Armada 1520 ,LPT2 port with no probs.
Car runs great , 13.2 last time out but scan tells me otherwise ;low O2 (constant , not changing) high BLMs with some top end knock counts so now I need to fix those.

 

Great going. I also use a COMPAQ. Presario 17XL365 to be exact and it works fine too.