Power Issues W/ 1999 FORD EXPEDITION : Fuel Filter?

[NHtoFL]

Eh, still an issue. Better now, but still there. It almost feels like a miss fire. The car doesnt buck or anything, but you can slightly hear it and feel it in the steering wheel.

Once I changed the fuel filter, the check engine light went off for about 150 miles and not it is back on.

Any idea if hooking it up to a computer will still help?

[GTOlover]

you said you have not done a full tune up on it in a long time a bad plug could cause a engine misfire. I would get the cap and rotor replaced, a new set of plug wires, a new set of plugs installed and replace the EGR valve then go from there and see it it still has an issue.

while you at it might as well do a oil and filter change.

but since you car is ODB II if it does misfire yes your check engine light will come on.

it could also be faulty O2 sensor, weak fuel pump, or a bad set of fuel injectors that could cause a misfire so best bet get it hooked up to a ODB II reader by a independant shop and get them to do a once over and get them to do a proper tune-up. better safe than sorry

[NHtoFL]

Took it to Autozone and they found a fault on the EGR. Replaced it and it runs great. thanks!

[NHtoFL]

Dont get it..

I have power issues.....
I replace the plugs, it goes away for 100 miles or so
I replace the fuel filter, it goes away for 100 miles or so
I replace the EGR, it goes away for 100 miles or so

Every time I do work, or add fuel injector cleaner, the problem goes away. Now it is back, no where near as bad, but its there.

It feels like a skip, possible miss fire. Before I replaced the EGR, the computer said it had a bag EGR & piston missfires. Once I replaced the EGR and ran it for 50 miles, the computer said it was clean, no issues. Havnt brought it back to get it rechecked again, but I am assuming it is going to tell me its a miss fire.

Any thoughts? Plug wires?
Is there a concern if there is a miss fire and I need to take this on a 1800 mile trip?

Jason

[Rica92]

I have a 99 ford expedition xlt and I think I need to change it. Where is it located

[Egobop]

I have a number of suggestions here. Your problem can be caused by many different things. It can be an injector, fuel pump, coil, etc. Changing parts to try and fix this can become not only time consuming, but obviously, expensive as well. The code readers everyone seems to be referring to are emission code readers. There are real scanners that can read codes off of the ECM, TCM, BCM, etc. that do not kick the "Check Engine" light since they are not emission related codes. Also, on Ford vehicles you can have a misfire that does not light the "Check Engine" light since Ford designed it to only kick the light for severe misfires. You need to find a shop that has a real automotive diagnostic scanner and not just a code reader. These will have the ability to check "Mode 6" for Ford which will alert them to a misfire that is not bad enough yet to kick the "Check Engine" light or an emissions code. If you do take it to a shop mention mode 6 to them and if they look at you like they have no idea of what you are talking about go to another shop.

I do a ton of side work on vehicles and can tell you that nowadays there are certain issues on vehicles that simply can't be correctly diagnosed without a good scanner. You do not want to take it to a place that just keeps swapping parts until they find what it is. That is the difference between a parts changer and a true automotive technician.

I will suggest that you definitely get a true diagnosis on your vehicle done soon since more recent vehicles also have many parts (especially emission and electrical) which can go bad from another part being bad for a long period of time. For example, a bad part in the emissions system that can leave the computer in "open loop" can turn a problem with a simple sensor into a bad catalytic converter and/or bad oxygen sensors as well as other part failures.

[Badbird2000]

I agree with Egobop.. The codes that Autozone reads can only give you a handful of parameters to check. I have a 2002 F150 with a 4.6... over a weekend trip to Ashville, i developed a misifre that was not severe enough to trigger a check engine light, but was pretty bad upon accleration.

I wound up replacing all my COPS (Coil on plug) and all plugs with Motorcraft. These modular engines don't like anything but Motorcraft plugs for some reason. Also, another thing in general to check with the 4.6 is the egr ports in the throttle body have a habit of getting clogged. I have had to take mine apart and clean it twice. Probably due again.. i have 148,000 miles on my truck. If you get the actual codes bring them back here or you can check out f150online.com... plenty of good peeps over there..

[A.L.Wheeler]

I have a 1999 Ford Expedition 5.4 L. Eddie Bauer. I d like to know if the coil is supposed to be loose. Its the first one on the passenger side. I dont know one thing about this engine but what i have read scares the ell outta me. This truck has always run perfectly til now and its sputtering, jerking under load. Hasnt gone dead yet. I checked all the Coils and they all were tight but you can move that one from side to side is that not good? Is that hold down bolt a ground?

[Nlambert]

The COP should not move. Pull it off and check to make sure the boot is seated over the plug correctly. You should feel a slight pop when it seats. Tighten the bolt all the way down.

The COPs will sporadically go in and out until they fail completely. Typically when I start to notice this, I go ahead and replace it and eliminate the problem. They're fairly inexpensive and really easy to replace.

[SD4020]

They are not supposed to move around. However, that is no indication whether the coils are functional.