hey guys, got some quick ?'s about a 5.4 on a 99 expedition.... first the guy wants to know if he can replace the distributor, but i told him its coil pack,so we went to look at it and i couldnt see anything cause it was night time, but i couldnt even see spark plug wires or anything coming off the heads...and i had a little mini flashlight.....im sure the car is coil packed correct? the main reason he wants to know is because he is lacking power sometimes and tonight it took a long time to crank over, it just spins for like 5-6 seconds and then it fire up, and he says it fires up immeditely every blue moon or so...... could it be a dieing coil pack. what other possibilities could it be... he changed the spark plugs recently, and fuel filter...
expedition they have coil packs they are up by the intake by the vavle covers and inj they run down inside and u cant see them just a single little bolt holds them down . i have replaced some on mine. mine was doing the same thing u would have to turn the motor over and over then it would start then 1 day it just stop running i had it took to a shop that a guy i race with has and he looked at it and it was the fuel pump that went out.also we have a autozone here and they can check the the codes and it will tell u what one it is for free i dont know if u have 1 there hope this helps on the coil packs
if you had a bad c.o.p you would no it.i had one go on me on my old expy and the thing wun chug andbuck at 3000 or so rpm's.i found which one was bad by using a obd2 scanner and chnged it.just a word of caution on those engines there are notorious for spitting out spark plugs so i dont know if your looking at this truck to purchase but thats something to keep in mind if the plugs are not torqued correct.phil
One thing you can do if you know what cylinder its misfiring on, is to change the swap out the coil with the one next to it and clear the code. Then when the DTC comes back on see if the misfire has moved to the other cylinder. This will let you know wether or not its a coil. Those coils are notorious for going out though.
Sounds like a fuel issue to me. Have you hooked a gauge up to the fuel rail and checked the fuel pressure while cranking, yet?
