hello from Syracuse, NY - OBD1 LT1 here

[sherlock9c1]

Hello everyone, I'm a refugee from the Impala SS forum. I've delved into just about every part of my '95 Caprice 9C1 except for tuning... until now. Looks like I should have started a lot sooner - I've been using Excel and Matlab at work for years, and much of this looks just like it!

[EagleMark]

Spreadsheets are a big help with sorting data.

[91ss]

Hey, see you've made it over here too, cool.

[EagleMark]

Yeah I found this place awhile back...

[91ss]

Meant Sherlock

[sherlock9c1]

I hate starting new threads when I'm SURE there's something already out there on it, but I didn't want to hijack someone else's thread.

My question:
I spent the fall datalogging and reprogramming my '94 GM LT1 Roadmaster and never had a connection problem using an old ALDL cable and Keyspan USB-Serial adapter. Recently I've been tuning my '95 GM LT1 Caprice and yesterday the data connection got very flaky, like dropping after every 8-15 packets or so. Multiple vehicle and computer restarts did not seem to make much improvement. The ALDL connection feels pretty physically loose if that makes any difference. Is there a troubleshooting thread somewhere about what to do with flaky connections?

[EagleMark]

Is it Datamaster or TunerPro file? Here's the one I built for TunerPro.

Have to connect after key on or engine running.

[sherlock9c1]

Datamaster. All connection attempts were made with engine running.

[EagleMark]

Make sure it is set for B body. F and Y body have differant modules on line and need differant commands.

[sherlock9c1]

Tried that. If you try using a Y-car mode on a B-car, it will lose sync every 17 messages. Found that out when I first started logging.