I have a '99 F-250 that has developed another miss. I had a COP go out a little over a month ago and replaced all the COPs with new ones from Global and new Autolite plugs. Truck ran perfect. I hadn't drove it much....maybe 250 miles. This past Sat I fueled up and drove about 130 miles and it ran like a dream. On the way home it developed a slight miss under load. Now it is missing pretty much constantly but not consistently if that makes sense. I pulled the COP wires one by one and the miss got even worse each time,same with the injectors. I finally got it to throw a code which was a 0355 and a 0354 on two separate occasions. I swapped out the 4 and 5 coils with known good ones with no luck, I pulled the plugs on all cylinders and they look like new plugs should. I'm down too bad fuel but I'm not sold on it. I filled up, drove 130 miles with no issues, drove halfway home with no issues and now it runs like crap. I would think bad fuel,would be bad fuel, as in it should have started running terrible shortly after I fueled up...right??? Short of a sledge hammer and a crap load of anger management, I'm lost. Any suggestions?

 

man thats too bad....i just got over the same problem. i've heard from many on here that you're supposed to stick with motorcraft plugs though so the autolites may be your problem. someone with more knowledge will chime in though.

 

the autolites really seem to be bad in the non PI heads and the F-250 didnt get PI heads until later I dont think. Probably the plugs.

 

BTW....I was wrong on one of the codes. One was a P0304 and the other was a P0355. I just dumped a can of seafoam in about 7 gallons of gas and drove it about 20 miles. Same results....it misses more as it warms up but it misses some even when cold.

 

That's what happens when using junk plugs, - at least yours ran for awhile, - mine didn't .

Yea, Seafoam won't help that. You need to install the right plugs. That's what I had to do.

 

P0304 Cylinder #4 Misfire Detected

Coil
Plug.
__________________________________________________ __________

P0355 Ignition Coil E Primary/Secondary Circuit

Ignition Coil A through J Primary/ Secondary Circuit Malfunction Each ignition primary circuit is continuously monitored. The test fails when the PCM does not receive a valid IDM pulse signal from the ignition module (integrated in PCM). Open or short in Ignition START/RUN circuit
Open coil driver circuit in harness
Coil driver circuit shorted to ground
Damaged coil
Damaged PCM
Coil driver circuit shorted to PWR

Usually a bad wire or a bad connection where the clip has broken so the pigtail does not latch properly.

E = #5
__________________________________________________ __________________________________

As said, installing the wrong plugs is never a good start.

No manufacturer can seem to escape selling a possible bad electrical component , -right out of the box. I've used Motorcarft and Global coils in the past and have had better luck from Global Automotive.

If you have a bad pigtail connector (coil,injector), Ford PT's can be had @ rmj

Good Luck.

 

Guess ill start by putting motorcraft plugs in. Brew, the Seafoam was just to eliminate the possibility of a clogged injector or bad gas. I dont know....I do know this is the most irritating ef'n truck i have ever owned. Ford should be shot for this design

 

Huh? Many of these 5.4L modulars go well over 200K miles with just routine maintenance. I would say they deserve a pat on the back for the design.

 

Yep, a pat on the back for blowing plugs out, being picky about the plugs they use, inconsistent COPs.....I have a 1978 chevy with a 350 in it with 240K miles on it. It has never blown a plug out of the head. I have a buick century with 215K on it that has never blown a plug out of the head......Go ahead and pat them on the back. I sure as hell aint going to

 

Properly torqued plugs don't blow out. Once they changed the torque from 15 to 28 ft lbs the blowouts stopped and they are not picky about plugs. You can use any plug that has the proper heat range and spec for the motor. I got 144K out of stock plugs and COPs and nothing blew out.

 

Well, I have to say that the plugs blowing out is either consumer error or the mechanic that installed them shouldn't be.

However, there was an instance in the 99 models where the plugs were not torqued properly from the factory. Those were recalled I believe.

Coils (COP systems) were a high tech design beginning in 97. I like the design myself, my first set went 165,000 miles. Then I washed the engine in all the wrong spots

There's a few precautionary measures that should be applied when swapping out a set of plugs that for the most part gets neglected. Prior models coil/distributor/wires you could get away with a somewhat half *** job, for awhile anyway.

Yea , there could of been a couple more threads in the heads, but I've run this design for nearly 300,000 miles now without a problem,- that for the most part, -I didn't cause myself.

Anyway, ~ Fram's first in line for the firing squad.

Good Luck

 

Out of curiosity then, why is everyone telling me that my plugs are the issue? I dont buy it but enough people have had the same issue and solved it by changing plugs that im going to try it

 

The ap/dp 103 and 104 Autolite plugs aren't specified to our manufacturers required heat range. Motorcrafts are made by the same company (Honeywell). Unfortunately for our two valve engines they differ enough to cause issues after install or go bad (foul) prematurely. This applies to the two valve modular family engines. These plugs over WILL overheat.

Do this. Compare a Motorcraft, NGK, Denso and Autolite spark plugs resistance = plug resistance and you'll notice exactly why these plugs do not meet spec.

If you have at-least the two on hand, - a Motorcraft and Autolite, compare those two and you'll notice a very wide margin in heat range. Look up heat range on the internet to see how important that is, -it's everything!

 

i understand there are issues with the plat and double plat autolites in the modulars but has anyone ever the tried the autolite iridium plugs in the modular engines yet?

 

Well I think I figured it out...I changed plugs back to MotorCrafts and it still missed. I drove it for about 30min until it was missing good and started pulling injector wires. I figured out cylinder 2 was dead. I pulled the coil with the truck running and no spark what so ever. I threw one of my old coils in and all is well now. Now I need to contact Global and exchange the coil for a good one. Thanks to all for their help