First issue:

Your experience with the 603 is perfectly normal. The length of time that the glow plug light illuminates is dependent on the ambient temperature. However, this time is unrelated to the time the glow plugs remain engergized and it's totally unrelated to the time that the plugs need to remain energized.

Everyone with a 603 needs to let the plugs go for a minimum of 15 seconds if they expect a smooth start. These two that I have are typical of this behavior. The '86, with it's older head and glow plugs is extremely sensitive in this regard.


Second issue:

The flaring when cold is due to a circuit that specifically increases the vacuum when the engine is cold to prevent banging on shifts. Apparently, when these trans were new, the unit would offer up a very hard shift when cold. So, M/B put a circuit to soften the shift. But, as the trans ages, the characteristic changes from a proper shift when cold to flaring when cold.

To avoid this flaring, and firm up the cold shifts, simply disconnect the vacuum solenoid that is sitting right next to the amplifier. The vehicle will then perform in similar manner no matter what the temperature. The cold shifts may feel a bit firmer, but, certainly not objectionable.