I have completed the TBI conversion and have my rig running almost where I want it. My symptoms are as follows. I have an unidentified stumble off idle that sometimes extends to the 1-2k RPM range. It generally is worse when colder. Keep in mind our ambient air temps right now are in the single digits to below zero. The other day it was in the mid 20's and I took it for a drive hoping to log some data. The truck ran pretty well, and I could not replicate the stumble when recording.

My question is, if I can record a stumble, can anyone here play back the log file and help me identify what might be causing the problem? I've replaced cap, rotor, plugs, wires, coolant temp sensor, and TPS. My fuel pressure is good and the injectors are spraying a nice even pattern. New ECM and AFI harness. No codes.

I'm so close to having this project complete but I don't want to just throw more parts at it.

Thank you!