Check Engine light and stumbling

[slow96z]

My wifes truck (2003 Eddie Bauer, 4.6, Bone Stock) has a check engine light and stumbles at idle. I took it to Auto Zone to get the code read but their reader would not connect. They kept telling me I had a bad fuse but they all checked out. I pulled the passenger front spark plug the other night to see if the plugs looked bad , thinking maybe that was causing the stumble but it looked fine (60K miles). I put it back in and that's when I got the light. Maybe the boot is not pushed down on the plug well enough. Has anybody ever heard of the OBDII port not connecting? Also, are there any known issues with these that might cause the issues I'm having?

Thanks!

 

[green03]

usually the obdII port shares power with the cig lighter. If there isn't power at the port they can't read the codes since the code reader gets its power from the connector.

Matt R

 

[slow96z]

Where is that fuse? The lighter might be out since I know my wife plugs her phone into the side port. I checked all of the fuses in the passenger kick and they all tested good. Maybe it's a cut wire somewhere.....

 

[lakmflx]

I would guess a cut wire or make sure the wire going to the cig outlet isnt loose or broken and its making good contact.

 

[green03]

is there another fuse panel under the hood on yours?

 

[kailor]

Check the idle air control valve.

 

[emf22]

There are several reasons why the engine could be stumbling at idle. One of the most common issues is the IAC. I had this unit go out on me too before. Another possibility is a leak in one of the vaccum lines. If you can, take off the plastic cover and check all the hoses connected to the intake and throttlebody for any leaks in the hoses or elbows. The elbows towards the back of the throttlebody have also been known to wear out and crack.

 

[dubedition2003]

Thats funny! I'm having a similiar problem with mine. I now have 60k on it and the cylinder 4 is misfiring.

Does any one know where I can find the spark plugs? I would like to try and do it myself before taking it to the dealer. Pretty sure that the dealer is not going to be too friendly with the price to replace them.

Cost me over $500 with my old truck to replace.

 

[lakmflx]

I dont mean to sound rude but if you cant find the spark plugs you should stop right there and take it to a shop. If you still want to try it all you have to do is pull the plug wire off and the spark plug is right there.....

 

[dubedition2003]

I haven't gotten around to look under the hood yet, I know that my old 97' plugs were under a lot of engine components and had to remove a bunch of stuff to get under there, thats why I am asking where the plugs are.

If thats the case with it in plain views sight then I wouldn't have to take it to the dealer.

 

[lakmflx]

A few plugs would give you HELL cause they are a pain to get to.

Im still looking for a socket i dropped somewhere in the truck lol...

 

[slow96z]

It was fuse 41. I'm taking it today to get the code read, but the light is now gone.

 

[blown87notch]

Originally posted by lakmflx
A few plugs would give you HELL cause they are a pain to get to.

Im still looking for a socket i dropped somewhere in the truck lol...

LOL yeah mine ate an extension of mine...it's gone forever.

 

[lakmflx]

Yeah, to this day i haven't found it but i know its stuck somewhere. Oh well lol.

 

[cfeltenberger]

I had the same issue on my '03 5.4L. It turned out to the be the no. 2 cylinder ignition coil. I was told that each cylinder on that motor has it's own coil, and it failed. Replaced (about $250 at dealer) and I was good to go.

 

[HI Expedition]

there is a tool collector compartment under the intake manifold. It also is good for storing nuts bolts and broken coil parts. I think that it is magnetic.

I also enjoy storing coil pieces in the spark plug holes. Nobody will ever find them there.

 

[AW_3_3]

We had this exact same problem last spring/summer with our 4.6. If you can get the OBD thing to connect, your looking for cylinder misfire. It seems the Coil-over-plug ignition coils go bad, and cause this. You also experiencing poor performance, much less power, and we had severe stumbling around 1500RPM. We had to replace 3/8 ignition coils, its a fairly easy fix to do at home, the parts cost $50 each. At the dealer, it is around $250-$300.