Kylemorgan22

05 Chevy Uplander 3.5 (2nd Engine, 100k miles)
April 2014 I bought my uplander with 112k on it. 2nd day of ownership the engine blew up. I was upset but oh well. Purchased used engine from junk yard with "77k" on it. Swapped them out, van "Ran" great!
2 months ago, October 2014, it was cold below 40 Id say. Crank up my van, starts fine, obviously it's going to idle a little higher then usual. I put it into gear, dies, cranks back up fine, put into gear, dies. Repeat the process and it does the same thing.
After letting it warm up until the thermostat pops it does fine. Cranks, drives, no issues.
Here recently it's been doing it as I'm driving but it acts like a miss. But everything engine wise shuts off and comes back on. Even the Speedo will drop. I'll be traveling 80mph/"miss"/Speedo drops to about 30 and catches back up to 80.
*Still no check engine lights*
I'm pretty mechanically inclined but not rich. I know I can start swapping sensors left and right but the money will start to add up quick.
So can you guys give me some ideas of what it definitely is not and what it most likely is.
Thank you,
Kyle

Papa Bear

Is the Check Engine light on?

Any stored codes in computer?

Kylemorgan22

none. No lights , no codes