Hoping an expert here can help me with a problem I can't figure out. I picked up a '99 E350 a guy was selling for parts because it had no transmission or torque converter. It had been sitting for a couple years.
The next day I found a used 4R100 on CL and grabbed it, and the day after that, a new torque converter from a local shop. My buddy and I installed everything along with a new starter and battery.
Then I crossed my fingers and turned the key. I was blown away when it started up first try. But my excitement was short-lived because it started doing this...
The weird thing is that the surging/almost stalling only happens in Park and Neutral; it goes away in any drive gear (see next video below). Something else I noticed in Park and Neutral is that the trip and main odometers click over miles like I'm driving even though I'm not.
Now when I shift to any drive gear (R, D, 3, 2 or 1), the surging/almost stalling goes away, the speedo goes to zero, the odometers stop clicking over, and it idles perfectly...
Does anybody have a clue what's going on?