Cant figure out occasional slow starts
 

Hey guys,

I've got an 03 Laredo 6cyl 4.0L

In the mornings after sitting overnight it fires right up. In afternoons after sitting all day while I'm working it usually fires right up...occasionally not.

If I drive it, turn it off, and start again immediately it's fine.

If it sits for any length of time from say 10 minutes to 5 hours, it has a lot of trouble starting.

It has new spark plugs and a new coil pack.

I'm also occasionally misfiring on cyl #6...always within the first 30 seconds of a trip and the CEL goes off after about 15 more seconds of driving.

Do you think it's worth buying one fuel injector and replacing #6, potentially solving both problems? If not, are the two problems even related? If not, what else should I be looking at.

Would love your feedback as I'm really struggling with this.

Thanks.

It's possible injector #6 is leaking down into the cylinder and flooding it and bleeding off the fuel rail so it's hard to start. I'd say try a junkyard injector to see if it changes things. Then you can go from there. :cowboy:

Thanks. I'm going to try it this weekend. May have to take a trip to Vince's in Utica.

Where is 518, NY?

I'm down near Oneonta now, which is actually 607 territory...

I replaced injector #6, pulled and cleaned 1 through 5, and replaced all the o-rings.

I ran it for a while, then let it sit for 30 minutes, and it fired right up again. Fingers crossed it did the trick.
The real test will be when I'm out and about tomorrow.

Thanks a ton for the help.