l92/6l80 will not start/can't read codes

[jorgensensc]

Originally Posted by 67Steven

Well, after a crap load of emails between Jon and I the last two days and little to no help from him other than he "needs to see the tune"...

I got sick and tired of trying to figure out what was wrong. So, tonight when I got home I unplugged the entire PSI harness and plugged in the OEM harness.

*A little background here: I bought the engine, trans and transfer which included the original uncut harness. Since it was from a Hummer, the wire harness to the ECM was extremely short, basically right in the space where my hydro-boost and brake lines were occupying. Wayne (tuner) modified my harness to be a stand-alone unit before I realized it was so short. So I made the fatefully wrong decision to grab the PSI harness since it put the ECM in the cabin.*

Anyhow, I plugged it in, connected the battery and turned the key on. Throttle pedal worked! I was a kid in a candy store! Turned the key to start and it started and idled! But died. It will start and idle for 4-6 seconds- I do not have the MAF, MAP or O2 sensors in place, as this was a quick install (and I stole those plugs for the PSI harness) just to see if it worked, so I assume when I get a good, complete harness it should work.

I am planning on an email to PSI tonight and explain what I did and see what he says. I have wasted 3 weekends and many week nights trying to track down problems on my end and it was his harness all along. I also spent a lot of time re-routing his harness to fit my install. I am trying to decide if I should have him send a new harness or just a refund and source a new one.

Oh, no throttle or transmission codes on the OEM harness!

I'll check back after my contact with PSI.

Great to hear!! Glad it is working for you. It probably isn't running right because it is probably trying to change over to speed density, rather than MAF. and your MAP isn't hooked up.
I'll be honest, at this point if I were you I would send the PSI harness back and just have your stock one modified to put the computer where you want it. You KNOW it works! But then again, I'm pretty frustrated with electrical gremlins right now!
Shawn