USB cable to Tuner Pro interface

**sgtpoliteness** · 04-30-2013

First time poster, long-time lurker.

First off, this forum has been a huge help in getting me to with 95% of completing my TBI conversion to my '77 Cherokee 360/TH400/QT.

Saturday evening, after getting just about everything installed, I wanted to re-test all my sensors (I tested them with Tuner Pro in a mock set-up in my garage before install). I'm having some issues getting connected via Hamilton Fuel Injection's USB cable to my 7427 '94 Chevy PCM. I never had an issue while bench testing it but it took me a good 20+ minutes of messing with it to get it to connect Saturday. After it did connect it worked GREAT the rest of the evening. Yesterday I spent at least 15 minutes with it, but no luck.

If I test voltage @ the data connector (F9 on my 7427) it reads 4.9V. Once I hook up the other lead to system ground (A1 on mine) voltage drops to less than 3.5.

At the bottom of the Tuner Pro window where it normally reads 'DA: Not Connected' or 'DA: Connected' it just reads 'DA: Connecting' and is brown (as opposed to yellow or blue). Has anyone run into this before? All my sensors are getting 5v reference and the power side of the injectors are getting battery voltage.

Thanks for a great forum!!

**EagleMark** · 04-30-2013

If you plug it into a different USB port it gets a different Comm port number... rerad this, it has worked for everyone so far.

http://www.gearhead-efi.com/Fuel-Inj...to-TunerPro-RT

**sgtpoliteness** · 04-30-2013

I see! I'll try that tonight when I get home. I tried to plug it into a different USB port last night and it wouldn't recognize the cable. This should help.