Diesel spraying on a hot exhaust manifold is insane, you were basically driving a bomb down the interstate and didn't know it. Nine miles of that is a straight up prayer. I would've been white knuckling it the whole way watching for smoke. Zip ties and hose clamps holding back a fuel leak at 60 mph is some serious redneck engineering and I mean that as a compliment.

Had a buddy deal with damn near the same thing on a -135 out at McConnell, only his was the yaw damper acting up. He chased it for two days, swapped boxes, checked wiring, the whole nine yards. Turned out to be a cannon plug back in the tail that only lost contact when the airframe flexed a certain way, and you could not make that happen sitting on jacks no matter what he tried. What finally got him there was having a guy sit in the cockpit and run the controls through full travel while he stood back there and wiggled every harness within reach. Any plug that let the pins rattle got pulled and re-pinned right there. Borescope helps too if the connector is buried somewhere you can't get a hand on.