I had a rather unique thing happen this morning on start up. I have had the white smoke blah blah blah since the truck was new and my injectors are fine with no fuel in my oil and no noise from a bad injector, ect. I had -4 F at the house this morning but I had plugged my truck in last night like I have been doing for the past 2 months. When I started it this morning it fired right off like usual but it revved to about 1200 and then down to about 600 and then back to about 1000 before leveling off at 750. While doing this, it was spewing out the regular white smoke but the uique thing was my EGT's. I was watching them for the first time on cold startup and they went over 400 immediately and then leveled off at 358. I got out of the truck to go back inside to grab my coffee. Upon return the high idle had kicked on at 1000 like every morning for the past couple months but the EGT's were at 240. I think the 3rd injection event might have something to do with white smoke and warmup. I think that the 3rd injection event occurs for warmup but since these trucks have no O2 sensor or other air/fuel ratio meter device, it may overfuel when cold and the startup result is white smoke until the engine and/or air is heated enough to lite the extra fuel which then caused my higher EGT's which aids in warmup. We all know that with more fuel and less air or boost, we experience higher EGT's like I did this morning. This is just food for thought and something that caught my eye this morning that got me to think about it. If everone already knew this or if it is the obvious then sorry for the remedial thread. Any comments?

 

I have noticed the same thing. doesn't smoke when warm. Maybe it is just getting to much fuel at start up. Never thought of that but that would explain things

 

Most likely is to help heat up the catalytic converter faster.

MikeyB

 

I watched my truck after start up this morning, a crisp 13 degree sunrise


White smoke, yada yada, then it quit smoking, like flipping a switch...Didnt fade out, thin ot or blow away, just quit smoking...High idle was set by me @ 1100rpm

I'm thinking the cat has more to do with white smoke, or lack thereof than anything else....Once the cat hits a certain temp, bye bye smoke....No matter what the ambient temp is

 

Without getting kicked off the site, I can think of one way to easily check...