High idle

[tae73]

This morning I went out to start my truck, and it was our first frost of the year 35 degrees according to the overhead. When I started the truck, idling around 750 rpm. Then the truck jumped up to 1000 rpm, and ran like that for 5 minutes as i scraped off the windows. I got back in and tapped the pedal and it idle back down. Is this normal and what settings are on the computer to make this happen? Also the truck was not plugged in.

 

[Kimber]

S'pose to do that. The manual has it in there, but I cannot remember exact temps... ..... something like until coolant temp reaches 150*, or the brake is depressed, or p brake is released, or go pedal is mashed.

 

[Dean Upson]

That's what it is supposed to do. Kinda gets your attention the first time it does it. I nearly dropped my coffee mug last winter when mine did it for the first time:--) .



Dean

 

[barbwire]

The way I understand it, diesels are not designed to idle at low rpms for extended lengths anyway, so if you have to let it idle, let it idle at the high rpm as long as it will. I think you will find that your eng will have a longer life. Just my $. o2

 

[bighammer]

I don't know about at startup, but if you leave it idling for a few minutes, it cut off 3 cylinders (turns off the injectors) and raises the speed to keep it running smoothly.

 

[mgonske]

Originally posted by bighammer

I don't know about at startup, but if you leave it idling for a few minutes, it cut off 3 cylinders (turns off the injectors) and raises the speed to keep it running smoothly.

I've seen lot's of threads about the 3-cylinder idle reflash for 2nd gens, but are you saying the 3rd Gen comes from the factory that way? ... that when it goes to high idle, all 3rd Gens drop to only 3 cylinders? I didn't know that...

 

[lschultz]

This does not apply to the 03 and 04 trucks. If you want this feature you have to have it downloaded to your trucks computer. They only come with the high idle from the factory if the temp. drops low enough and several other things are met then it will kick up to high idle till you step on the brake,push in the clutch,put it in gear.

 

[XcumminsX]

my truck did it this morning and i almost ran to turn off the ignition because i thought something went wrong but then i hit the gas and it went back down then i let it sit for a couple more minutes and it did it again. nice feature. scared the hell out of me tho:--)