Ok I have everything hooked up and ready to fire and something is wrong.
List of mods:
5.3 block 346 ci
224/230 cam
vic jr intake
d1sc
4l80e
nelson ecm
blah blah blah

A few days ago, I put the battery in the truck to charge the fuel system to make sure there were no leaks and the fuel pump turned on fine, probably 6 times in a row.

Yesterday I went to start it and all I heard was the starter click once. Turned it back on to try again and nothing worked, no fuel pump, gauges acting weird, windows don't work ect. I took the battery to auto zone and it checked out ok. Tried again, nothing. Put new battery in, nothing. Unplugged battery let it sit for a while tried it again and everything turned on, gauges worked, fuel pump came on, and the motor turned over like one time and then it went crazy again. When I pull the key out of the ignition the dash lights and head lights will stay on indefinitely. I put the stock computer back in just to see if it would crank and it does the same thing. ?????????????

Today I pulled the starter off and it checked out ok. Then decided to plug the battery in with the key in the on position and everthing started to work, but it would just click the starter and then everything would die again. I disconnected the battery and started over. Once the battery is plugged back in the clicker on my key works, put the key in the on position and it takes about 30 sec. for the instrument panel to light up and then sometimes after about another 45 sec something else will happen and the gas/volt gauge will come up and then it will act like it wants to crank, then nothing, all gauges back to zero but lights still on, radio, windows, alarm clicker ect. doesn't work.

Sorry for the long post, I really need some help.
Thanks.

 

Sounds like you have a ground you missed or something some where, or you have a loose wire. I would check ALL your wires.

 

check all grounds you should have one big one on the driver side and 2 little wires on the pass side behind the intake and make sure your tran selector switch is all plug in

 

As far as I can see, the only thing that is not plugged in is the evap sensor. I had Nelson delete it anyway. There are no other wires/grounds not connected.

Anyone else, please
This is really starting to suck.

 

Problem solved. Apparently I missed a ground wire in the back on the passenger side. Tightened it up and boom this thing sounds insane.

 

those ground wires are a pain in the butt.. glad you got it running.

 

Thanks, you have no idea how stressed I was about it. I've spent so much money and time on this thing and then it started acting like that, really had me worked up.

 

haha, yea i swapped my 6.0 in and it wouldn't start.. re grounded re grounded re grounded and it ended up being injectors.. junk sucked..