My Expedition is idleing extremely rough. I just changed the spark plugs, fuel filter and air filter and no codes are coming up. It has 97000 miles and had maintained proper maintenance. Any ideas???

Have you changed your fuel filter? When is the last time you changed your sparkplugs? Have you had any codes on the computer? Heres what I would do. First change your sparkplugs. This is a 4-6 hour job. You have to unbolt the cop(coil on plug assembly). After you change the plugs your truck will run rough. Drive it around the block then back to your house. It will take 3-5 restarts before your truck quits running rough. Reason for this is because your computer is trying to "relearn" the firing order. I have done this several times so i know what i am talking about. You can even look it up. Your 2000 expedition is a dang good truck with a great engine. After your computer relearns the firing order then the rough idle will be gone. Then I would take it out on the freeway and run it hard for 5-10 miles. If you experience a miss or two then that means you need a new cop(s). Get a code reader and it will tell you which cop is bad. Cops are expensive. I bought 6 new ones on ebay for $40. If you buy from autozone or ford dealer then you are looking at about 80-100 bucks a piece. Tell me if this helps. Ford makes a good truck and the expedition is a great truck. Mine is a 2000 expedition also. I have 248,000 miles on it and running strong with no burning oil. Good luck.

Sounds like a cold start problem from the description. You should check the coolant sensor circuit and the idle air control motor. Make sure the coolant level is full or the coolant sensor will give a false reading. Check the idle air motor and throttle plate for varnish and sludge and clean with a carburetor cleaner listed as oxygen sensor safe. Other checks should include condition of filters, plugs, wires and vacuum lines and line routing. If you have a scan tool, the data stream would be the fastest and easiest way to check the sensor circuits.

Are you sure the spark plug wires are on the correct spark plug? Recheck the firing order and spark plug wires. Additionally check timing on distrubutor

1. Error Code 24. Intake Air Temperature Sensor.
Solution:
Check the following:
- IAT Connector and wiring.
- Intake Air Temperature Sensor.
- Engine Coolant Temperature Sensor.
- ECM.
2. Rough Idling when the engine is hot.
The following are the reasons due to which the engine can perform bad when it is hot.
- Fuel pump control circuit.
- Fuel pump pressure.
- Fuel injectors.
- Non Return Valve clogged, located on the lower side of car chassis above the fuel tank.
- Engine compression, valve clearance, spark plugs.

Spark Plugs --change every 3 years?
Front O2 Sensors-replaced at 100,000 miles?
MAF Sensor-cleaned?
Egr System works as it should?
No cylinder misfires?
No Vacuum Leaks anywhere?
No stored codes?

Shall I keep going?

You have to work on all vehicles at least twice a year
& look for problems

Alternator has no ac leakiage
Fuel filter new
Fuel pressure good
Air filter?
Throttle Plate doesn't stick?

Sounds like the fuel injectors are dirty. run a bottles of STP or other fuel injector cleaner in the next two tanks of gas. Also if not done before change the fuel filter inline from the tank. Or maybe change the air filter, especially if you have been driving in an area that is very dusty.If the filter is clogged or full it will restrict the flow. These are some cheap fixes. If they done work then you can have the injectors cleaned at a shop but that is a bit more expensive. I hope this helps.

I Have a 1999 ford f150 4.6 that back fires and is just running really ruff when idling alot of nack fire a sord of like a pulse going on what is my problem?

Bad fuel, bad air filter,PVC valve, EGR valve

Take it to a auto parts store and have the computer scanned for the trouble codes. Autozone will do it for free, then you will have a better idea whats going on. It could be a number of things causing rough idle. I would get it scanned before replacing anything else. I hope this helps.

The thing to do now is a fuel pressure test pump could be weak just a few pounds under the recamended pressure will do that weather its mechanical or electrical . Is there a filter in the carb. wear fuel fine hooks? If none of this is an issue at least you can eliminate fuel deliverly as the problem.