I own a 2005 Dodge Magnum SXT, with 3.5L six cylinder engine, RWD. I bought it new, and it now has 108K miles. My issue is it takes a long time to start up, say 6-10 seconds of crank time, sometimes a bit longer. While cranking, the “Check Engine” light is on, but turns off immediately once the car is started. Once started, the car operates fine. This has been happening for at least 3 years. The trick is that it only happens some of the time. It happens when it is warm outside (say above 80), but starts up just fine in the cold. When I’m at home, I keep my car in the garage, which does get rather toasty during the warm season. This problem happens everywhere though when I start it up (not just in my garage) when it is over 80 or so degrees. The only time it starts up fine is if it is below 80, or if it has been running recently (maybe within the last 30 minutes). Any ideas what the problem could be?
Try this the next time it is likely to crank a long time: turn the key to on (to where all of the dash lights come on) but not all the way until it cranks. Listen for a 2-3 second hum probably from behind you. Turn the key back off - back on - hum - off - on - hum…
Do that about 5-10 times and then crank it. If it starts right up then you probably have a bad check valve in the fuel pump allowing all of the fuel to drain back to the tank. The long crank is likely about getting the fuel back up to the rail at the right pressure.
If that is it then the only cure is a new fuel pump - or you live with it the way it is until the pump completely goes.