We drive a 2007 GMC Acadia that has a remote start. The remote start works perfectly 100% of the time, even if the engine has been cold for a long while. Once I enter the vehicle, all I have to do is put the key in the ignition and turn it slightly so I can put it in gear, there’s no noticeable change other than the radio turning on.
However, when I try to cold start the engine by normal means, that is, no remote start, just inserting the key in the ignition and turning it, the engine has trouble turning over. If the vehicle has recently been driven, there’s no issue with the engine turning over, so this only happens during a regular cold engine start.
I would think if the vehicle had trouble turning over starting it normally, it would also do the same via remote, but that’s not the case. And of course, I’ve taken it to my mechanic but they can’t replicate the issue, probably because they aren’t allowing the engine to cool long enough.
Spark plugs are relatively new, FWIW.