Hi,

I have a 1998 Navigator with the 5.4 engine and 106,000 miles. It has a miss when the cruise is on and there is a slight rpm change to go up a little hill. It will miss also without the cruise when you only need to make slight speed increases. Stop and go in town and wide open it runs great. no codes and no idea, please help.

Thanks,
Charlie

 

Sounds to me like a bad coil. I would check all of the coils to see if they work properly.

 

I feel like it might be a coil, but I have no idea how to check them, without any codes.

Thanks,

 

i went to autozone they will scan it for you ,had similar problem was number 1 coil over

 

I think they can only scan the codes and I have already scanned it and there are no codes. If I am wrong, someone please tell me.

Thanks,

 

You're correct, if no codes showed up for you then they're not going to show up over at Autozone.

 

I tried to scan for codes on mine and it was no help. If you have one that is bad that is an easy fix. Buy a brand new coil pack and replace each original one, one at a time. Rev the engine and see if the miss goes away. If not continue onto the next seven one by one. If you have two bad ones...good luck as that takes more troubleshooting.

My advice, if you find the bad one...replace all the rest. You never know we they are going to fail and in the future a failure should only be one at a time. Keep one or two of the good ones for emergency back up in the glove box or somewhere (and the correct nut driver wrench to unscrew them). I have a used but good coil just in case so I can be back on the road in ten minutes should a future failure occur.

Remember to put dielectric grease inside the boot before permanently mounting the new one(s). Also, never ever,ever pressure wash over the coil packs. They will hold water forever and it doesn't boil off even with a hot engine. I bought an auction vehicle and had 3 coil failures within a month because they never dried out from the seller "shining up the engine" for the auction.

While doing all coil packs you might as well change plugs since you are "dug in" and call that type of maintenance forgotten about for quite some time.

Hope this helps.

 

I'm betting you don't have a miss. What you describe sounds to me like torque converter chatter. This only happens when your overdrive is locked up, right? If this is true, try disengaging your overdrive at the same speed and try your slight acceleration test. If it goes away, it's probably the torque converter.