Peter,

Concerning the 603, and only the 603:

Mine needs a good 25 seconds of glow to ensure a perfectly smooth start with no misfiring for the first 30 seconds.

Your opinion on the following, please:

Would a brand new set of glow plugs get this time down to 5 seconds or so (effectively glow light time)?

Discussion is at ambient temperatures of 45 F. to 70 F. It is clearly understood that all bets are off below freezing.

I've already bought the plugs and am considering removing the intake so that I can clean it up a bit. But, I'd rather not risk the removal of the plugs if it won't buy anything.

Marshall had commented that the 603 should do better than what I currently experience if the glow system is functioning "as designed".