CARSmith56

Thank you! We'll check out that harness first thing Monday!

Unit ran fine; dropped a valve; new head; ran poorly; replaced turbo; roadtested great; then quit on the way back to the shop. No codes; we've swapped ECU's with running trucks; replaced plugged EGR cooler; pulled apart all harnesses looking for wiring problems - no luck. Two new fuel pumps; cranks over good, then instantaneously starts and quits. Corporate Mack magicians are stumped, anybody out there with any ideas where to look next?! Heeeeeeelp!!