Hello everyone,
On our work truck, an '08 Resistol, sometimes when it starts it revs right up to 1000 RPM, then sits there from anywhere from 5 to 30 seconds before the revs drop to normal idle level... It only does it occasionally too... Anybody have any ideas why it may be doing this? It's got the 6.7, auto, bone stock... Any insight would be appreciated!
Cheers.

 

EGR system functioning. Normal operation for warming it up. At times you may also notice the EB engaged also. This is also used to warm the engine quicker. Mine used to do that sometimes. A Smarty cured it.

 

First off, serious props on having a Resistol for a work truck. The engine will automatically go into high idle after one minute of idling if the temp is low enough.

 

That green eyed monster in me just ignored it...

Yea cause Im jealous.

 

Thanks for the replies so far guys! Yeah, the boss loves us, so he buys us these fancy trucks! What you guys are describing is what normally happens in the winter but this is different. It's relatively warm here right now, temp. in the mid 20s to low 30s and it usually only does it when the truck is warm. As soon as it fires up it goes straight up to 1000 rpm, no idle or anything at first but straight to 1000, then after a few seconds to 30 seconds or so it drops to normal idle, and no EB coming on...

 

I still tend to think this is normal. Even with the truck warm, it will suck in the cold air (which 20 to 30 is still cold enough to activiate) and it will high idle until it runs its course.

 

I've fired up after towing hay maybe after 10 minutes of sitting and notice it idle up but my coolant also is maybe 225 also at the time. Thinkin maybe high temps cause idle up for cool down??

 

If the engine has any difficulty firing on start it will go to high idle. I would check fuel filter, fuel quality and maybe an overall check on your fuel supply. If you have the means to pull codes, that may help. I don't think its serious.

Nice truck BTW.