The other night my wife got into my truck and turned the key and half started the truck and let off of the key before it fully started. It made a weird noise and started to smoke(not electrical) but oil or coolant but very lightly. After that I tried to start it and when I do it will start immediately rev to 2-2500rpm and drop right back down and die. If I keep it above 3k rpm seems to run smooth. Any ideas where I should start?

 

Check for codes. I would believe it would barely run if the timing chain jumped but is a possibility under that situation.

 

Might be a good idea to look for a vacuum hose that got blown off at the time it pushed back.