Happens at all levels of fuel (empty to full) -- when parked on a hill if I start my car up, when cold, my car sputters and misses, and has a very rough idle.
Does not happen when the engine is warm or when I am parked on a fairly level surface.

Anyone seen this issue yet?

 

This is a guess, but I'll bet it's when the front of the car is pointed up hill??..
Again major guess, but maybe weak fuel pump? (Not pumping enough to overcome gravity until fully warmed???)
subscribing

 

just a guess but maybe because of the oil is running to one side of the pan... i would try to turn the key to on, wait a few second and then turn the car on all the way

 

Having the key at "ON" wouldn't help with oil flow because unlike the fuel pump, the oil pump is accessory belt-driven. As in oil doesn't move until the engine is turning.

 

maybe the car doesn't like to be parked on a hill.....

 

I would think oil is about unlikely as the fuel pump idea....But to test this just pull your fuel pump relay, crank the engine 5 or 6 revolutions, replace fuel pump relay and start it.---I find this unlikely for alot of reasons.
1.) Because it runs rough longer than the second or so that it takes for oil pressure to build. (I assume)
2.) Just doesn't make since
Neither does the fuel pump idea, but it's worth checking....Find your schraeder valve on your fuel rail and hook a pressure gauge to it... See what it reads after you start it.

 

Could be a short or ground issue. Some connection being made when the car is on a slope? Some part of the electrical system that only comes into play during warm up could be making contact with something it shouldn't when the car is tilted.

Also check the vacuum lines. Same theory as electrical. Something loose bumps a loose vacuum line that's part of the warm up cycle.

 

Thanks for the suggestions -- I'm checking vacuum and fuel pump first!

 

to check the fuel pump just open the door and turn the key on, listen for a sound coming from the pump. then try it when not on a hill and compare. if it seems to click/pump faster on flat ground then its probly the pump. and its not oil. the engine wont start without oil pressure.