Check engine light is on with the key off and out!

[4byT100]

I just put a JDM 3.4 in my T100 to replace the tired 200K+ 3.4 it came with. It was blowing a head gasket. The new one started right up and after burning off the catalytic converter (antifreeze and oil) it settled down into a nice idle and ran fine. I felt great, I had my truck back. I drove it around the block a few times and then check for leaks or problems. It was ready for the road. My low gas light was on so I headed out for the gas station, got 2 block away and it stalled, wouldn't start. Cranks over real good so I thought I was out of gas. I put 3 gallons in and gave it a shot of carb cleaner but it won't fire. The check engine light came on so I put my code reader on it but it could not connect. When I take the key out the check engine light is still on. not as bright but still on. I'm hoping that is a signal as to what has happened to my spark or ignition. Does anyone have an idea what has happened to my t100. Everything seems normal just no spark! Is it just time to put it in a shop with good analyzing equipment? This was a big job for me and I wanted to own it but I don't want to fight a losing battle. Any ideas? Thanks 4byT100

 

[4byT100]

Loose ground!

In my haste to put it all back together I just hand tightened the 3 ground wires that connect to the front side of the intake plenum. After driving it around for about half an hour they loosened up and it quit running and the CEL came on and stayed on! After lots of searching and head scratching (about 8 days worth) I found them loose and tighten them up and it started right up and its running fine. It was right in front of me all the time!