94 6.5 suburban randomly wouldn't start. It would crank over fine and would eventually start, sometimes 5 minutes, sometimes 5 hours. Replaced the pmd, tried unplugging the optical sensor, and neither made a difference. When it does start, it is very loud (can hear it in the video) and when it makes the loud noise the speedo goes up to 10 mph then back down, even though it's sitting still. After 5-10 minutes of idling it clears up and drives fine, but once you turn it off there is no guarantee it will start back. Thanks in advance.
Loud 6.5 diesel: http://youtu.be/tKFM4Xip-3Y
Loud 6.5 diesel: http://youtu.be/tKFM4Xip-3Y