What causes our cars to start slowly from the factory? I noticed my car does it and everyone else I know who has a mustang (different years too), they all start slowly. Why? What causes this? Coil packs? This seems to be a factory thing...

 

both of my mustangs had/have occasional hard starts when its warm. i really have no clue why, but its never been a big enough issue for me to pursue. both started perfectly when the motor was cold though.

 

Mine pops right off hot or cold, though I admit to tweaking the Cranking AFR table in the tune to get the hot start heat soak problem fixed.

I don't know about the '96-'98s as I've never owned one, however if a '99-'04 has starting issues there's something wrong--I've tuned a number of them.

That said I've owned scores of cars with plain ol' Kettering ignitions, and wasted spark DIS coilpack systems--the first thing I'd look at would be plug wires; very good plugs wires will last (maybe) 30k to 35k miles before they start to fail, cheap ones might not make 15k...

 

I had that problem a few years ago. one of my coil packs went haywire on me. So Ireplaced all 8 w/ Summit ones and made my own hyper gruond kit while everything was apart.
I didn't feel any HP gain, but as a result the stang fires up almost immedatly after i turn the key. Personally i would'nt spent $250 on aftermarket Coil packs just achieve this, but to each his own.