i have put new plugs and wires in and still misfire in cylinder 3. Has anyone had to change a coil pack in their truck , if so what were your symptoms that lead to it? Also egr is insufficent flow or something .. has anyone had to work on that. Details on symptoms and troubleshooting. thanks

 

Post your DTC's from the scanner, you'll get more specific help.

 

I replaced my coil packs not because of a problem but for performance reasons. I just wanted to say that if you do end up having to change them just make sure to mark which wire met up with which notch on the coil pack or you'll experience other problems.

 

The egr trouble probably means the passages under the throttle body need cleaning. This is a typical problem with these engines. Clean under the throttle body and maybe replace the flow sensor and this should fix your egr code.

 

I recently changed a coil pack on an 01 expedition 5.4 Triton Eddie Bauer Edition so it should be similar.

Codes read cylinder misfire on x cylinder.

Vehicle runs rough and when you step on the gas it kinda hesitates/bucks a bit.

Before reading the codes I changed the oil, fuel filter, cleaned the K&N air filter, put in some injector cleaner, ran premium fuel through it, seafoamed it, and even changed all the plugs and plug boots.

I did all this as a tune up for the vehicle because it needed to be done and it still ran like crap. Finally I found a parts store that still carried a obdii code reader (all the others no longer read codes for free, even autozone), and found the misfire. Bought 1 coilpack, swapped it out, of course it was number 7 which was on the drivers side rear and the hardest to get to, and it felt like a new vehicle.

 

7 of my coil packs are original (1 was destroyed when #3 plug was launched from the motor) on my 97 5.4L with 250K. Engine runs smooth, and I have no indication that they need replacing.

 

come to find that the compression in cylinder 3 is low (100 psi) looks like I'll be running on 7 cylinders until I replace motor or tear the heads off and see whats wrong.

 

Get this as soon as I thought I was looking at a big job on this truck all I did was change the oil and put some oil treatment in. Went and filled up with high grade gas and then put a bottle of seafoam. Drove it for about 20 miles and it hadnt missed since then. Can you believe that. It must have been a little carbon built on the valve.

 

Idunno, it's possible I guess, -I just doubt it lol. Check the compression once more. Not sure how you checked it before, but check it the same way.

 

LOL i guess i spoke too soon. 30 miles later it started misfiring again. Sometimes it seems to be running great and then it will misfire spiratically. Any suggestions.. think it needs head work or what. It still drives strong but at idle (stop light ) you can feel it misfiring. Not a dead miss.

 

whats the compression on the other cyl's? i did this on mine and they were all withing 130-145psi range. what kind of plugs are you useing?

ive changed the coil packs on my truck there pretty easy to do 4 bolts and a big plug. when you do it. look and see were the wires are take 1 wire off the coil pack and put it on the new one. by doing it one at a time you wont mix them up