Should GPs burn on hot starts?

[AndyL]

I am still trying to understand why my truck starts better cold (1-2 seconds) than warm (3-4 seconds). If I turn my truck off completely and immediately turn the key on again the GPs cycle for a short period of time. Is this normal? My 6.2 and my farther-in-laws D-max won't even turn on after 30 minutes of sitting, and start instantly.

[chickenhunterbob]

Andy,

On my '94 6.5 what you observe is normal. That is to say that the glow plugs heat each time the key is turned from "off" to "on" regardless of engine temp.

I believe the glow plug cycle time is regulated by coolant temp, so if the engine is warm, the glow cycle is quite short, and increases as the coolant temp drops, but even when the coolant is hot, they burn for a short while.

Bob