In starting my truck this morning I noticed that my Glow Plug light did not come on this morning, tried to start it and it would crank but no fire. Switched the ign on and off several times, finally got the light, and it fired right up as normal.

I've read on the board that there is a temp sensor that the ecu uses to control glow plug cycle duration and operation (if it is hot, they do not come on). What/where is this sensor?

I have also experienced in warmer weather (70F+) a higher idle speed. normal is about 650-700, when the truck is hot and a warm day I see 900-950. Could this also be an ecu controlled response to a bad temp sensor?

Short cycling of the Gp's is common and can be a weak connection or the GP relay. I find that if I turn it off and leave it for a few minuites it get's passed it.

The high idle is always there engine hot or just occasionally?

When my glows quit the terminal on the relay had melted off, externally nothing appeared wrong as the rubber boot was hiding the burned terminal.

The high idle is only there when the weather is warm, and the truck hot. Through the winter, low idle with the truck hot or cold. We had a warm streak in march, had high idle, then it cooled back off for a month, back to low idle.

If the GP relay were bad, would the dash light (GP) still be lighting?

My WTS light was lighting, and then was "clicking" but the volt meter never moved.
Pic's available from my meltdown at this thread.
http://dieselplace.com/forum/showthread.php?t=21703&page=2&pp=10

The actual pic is here:
http://dieselplace.com/forum/attachment.php?attachmentid=1686

Loose connection on relay cooked the terminal. It heated up the plastic and the plastic interfered with the connection on the contact. Thus, no glows.

I checked the connection, and have had no problems with the GP's since, maybe it was loose.


Thanks for the help