hard starts on any new car can be considered a fluke. fuel injection is so dependable these days.

on YJ's everyhting is plenty strong STOCK its as soon as you start modifying that you need to worry about component failure.

my 231 blew the slip yoke on a burn out when i started getting axle hop/wrap. i was on dry fresh pavement running new 31X10.5 mud terains. if you were to do the same burn out with stock 28/29 by 7/8 tires you could have burnt out for days with no damage.

i think you'll find that all cars have that same issue. they work great for what they are designed for. When you start using it outside those limits, things break