This is on a 87 gxl t2 swap with a elite 1500, haltech terminated harness, and ign-1a coils. I followed the instructions for the grounding.
when i start the car it runs a little rough then smooths out, the longer it runs it starts popping and gets a lot of afterfire. i have double checked the timing and moved the routing of cas wires and the coil wiring. originally I was getting a home trigger error at that time i was using RX8 plugs. after changing the plugs back to the FC plugs the home trigger error went away but that didnt solve the running issue. i have been on the phone with haltech's tech support for many hours trying to sort this out. the tech wants me modify the cas by taking 2 opposing teeth out of the 24 count trigger wheel. i have sent it off to a machine shop for this mod. i am modifying a spare cas. this is a confusing problem.
also i have tried different filter levels and arming volts. data logging doesnt show anything.i also had haltech bench test it. no problems found.

 

Also I did check the timing while it was popping and getting after fire. The timing was moving. Sometimes it was 90 degrees sometimes it was 180 degrees. That was on the leading front rotor. Even when I locked the timing there was still some movement ~15 degrees.

 

What could cause this interference? Thanks in advance

 

Ok. Found out that there was 3 wires that weren’t crimped right in the terminated harness going to the leading front rotor. That was my interference. Also the primary injectors weren’t working right ( even though I just had them cleaned and tested). Car runs as it should

 

Congrats! Let me know if you need any help with tuning. RGHTBrainDesign@Gmail.com