New miss
Thread Starter
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Laughing Gas
Joined: Feb 2003
Posts: 1,242
Likes: 2
From: Bartlett, TN
New miss
We bought gas at a local Sam's Club a few weeks ago and right after started to get a hard miss just above idle speed. When we step on the gas, it takes off great. It only misses when trying to maintain 40 - 45 MPH. I don't know about 55 - 65. We ran all of that gas out of the tank and put about $40 in (not quite 1/2 tank in a 01 Excursion) and it still does this. I was hoping a new tank would cure this since a tank started it. Was that just a coinsidence or what? It is a 5.4 with about 75k miles. Even when it is running the worst I am getting no engine lights! Autozone says they need a light to pull a code. Does the Ford mechanics need a light as well?
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
Mostly yes, or you have to get lucky and have it miss while the reader is connected. If refesh fuel didn't solve it, then it was a coinicedence most likely. Try some gas drier. It could have pushed the problem into occuring. I am thinking spark plugs if it's not the gas. If it's good under load and good idling, the plugs can't be that bad, the cops should be fine, and the IAC is functioning. The IAC could be sticky and acting up.
Post Fiend
Joined: May 2006
Posts: 10,007
Likes: 4
From: Central Florida
IAC is idle air control.
The plugs are up top, pull the cops and with enough extensions and some swivles you should be good.
What LX is describing could help point you in the right direction. A soft code could hide, but still reside in the computer.
The plugs are up top, pull the cops and with enough extensions and some swivles you should be good.
What LX is describing could help point you in the right direction. A soft code could hide, but still reside in the computer.
Thread Starter
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Laughing Gas
Joined: Feb 2003
Posts: 1,242
Likes: 2
From: Bartlett, TN
I got to change the plugs this weekend. I also bought 3 new coil boots. I did check the ohms on the coils when I had them out - they all read around 5 ohms. 2 of the boots (on the 2 rear most cylenders on the drivers side) were damp and the spring wire somewhat rusty. After changing them, our miss is gone. We changed all the plugs except the rearmost on the passenger side. If you've never looked under the hood of an Excursion, you won't understand. So far after 2 days of driving, we're running fine.
