Just had a question... We just got back from camping in the mountains. For the trip back, there was about 20 miles of downhill road from the campsite to the freeway. So after we loaded everything up, I started the truck, waited about a min. then took off. However, it took about 10 miles before the truck even warmed up a little because there was no load on the engine going downhill. I had it in 3rd and 4th gear most of the time down. I know it's not good to have the truck idling for long periods especially when cold because not all the fuel gets burned and it begins to wash the walls of the cylinders. So I was wondering if driving the truck cold for long distances like what I did was also bad for the engine.

 

going down hill like that won't hurt it abit as far as fuel not burning , because the injection pump is actually injecting NO fuel in a situation like that , just coasting down a hill.

 

The injection pump is ALWAYS injecting some fuel, if it's coasting then it just injecting the same amount of fuel at idle. The pump is mechanical, there is no valve to turn the fuel off when coasting.

I can't see how the engine can be hurt in this situation...there's no load on the engine, which means there's also very little stress too.

Chris

 

that's what i thought too , but when the engine coasts , it requires no fuel , the goveroner actually makes it stop injecting fuel until you press on the pedal , or the engine gets down to it's idle rpm.

 

Oh yeah... I always thought there's some fuel going into the cylinders. Where did you hear this?

 

It was on this forum somewhere, that's all i can remember. If i had to hazard a guess as to who i heard it from , i would say probably Bill (Infidel)