5.4, runs like bad c.o.p. or bad plug, no codes or pending
 

I have a 98 F150 4x4, 5.4 automatic. It is running rough like it had a bad c.o.p. or plug. I have scanned it, but there are no codes, no pending codes, what else could it be. I really dont want to go through the hassle of pulling the plugs and coils. I have replaced 7 of the 8 five months ago. #7 is the only one left, i jsut couldnt get the to the screw because of the fuel rail.

You need to drive it with a data logger that will count misfires.

okay, where do I get one of those

My Diablosport Preditor had one.
Might be cheaper to pay the dealer 1/2hr labor to diagnose the issue.

When my 5.4 had a bad COP, it didn't throw any codes for a good 2 weeks. Finally, I started pushing the engine and trying to keep the RPM's in the range I noticed the misfire. Finally the computer threw a code and pointed me to the bad COP.

hey guys, i'm glad i found this post. my 5.4 tritan jus started running alittle ruff. like a fouled plug or vac leak. couldn't find a vac leak but it coulde use new ones. is there a kit for sale out there that sell a complete vac line kit?

i'm going to attempt to change the plugs. sorry I don't know what a COP is?? any help? thanks

coil on plug, you will see what they are when you change the plugs. you are gonna needa 7mm socket and a 5/8 plug socket and a piece of fuel line tubing to get the plugs out. #4 and #7 are the hardest to get out.

Pushing the engine hard might get a code. Try a full throttle start to 75 mph. When I had the same problem, that's what I had to do to get the position number of the COP.

As for a vacuum leak, the most common is the PCV hose elbow at the rear of the intake manifold.

i pulled pvc out of valuve cover while engine running and had alot of vac to it... i will look it over and see if there is any problems on the elbow

They Should Know This
 

I had same problem that you describe and took my 97 expedition to Three diff dealerships in portland. No one could figure it out because it was not a detectable problem( the computer would not tell them what to do so they did nothing)... I took the truck home and knowing a little about cars (a lot actually) I went to the area I thought was the problem. I took the throttle body and bypass valve off and noticed quite a bit of corrosion in the bypass valve. This valve allows air around the throttle body upon initial start up and then closes after warm up. You will notice it's path one hose is connected in front of the throttle body and one on the intake side. It is round cylindrical in shape and has an electrical plug connector on it. Mine was stuck in the open position and for about 50 bucks at the dealership for the new part i was good to go. any questions just ask....(P.S. I have all but lost hope in the ASE real mechanics are certified in the back yard and proven on the track!!!!!)

COP means Coil Over Pack .... It is the little black individual coils that attach to the top of each spark plug instead of having just one coil and a distributer like on the old style ignition systems. This allows the computer in your car to more effectively and accurately deliver spark to each cylinder. Each little pack is its own coil. You can even buy after market coils to boost performance but they are pricey.....85 to 200 bucks each.

Our performance coils are a lot less than that.

Our new Ford COP’s, the Sultans of Spark(S.O.S.), have
been designed with both durability and performance in mind.
Please see them at:
Ford SOS Coils
Quality was the main feature we stressed when we went to the
drawing board on these coils.
By the way, for those of you who only need to replace a defective coil,
our SOS Coils are available separately.

has anyone used the summit cop for the 5.4l or 4.6 that sell for like $240ish

DON'T buy the Accel ones. I've learned a lot about chasing down which one went out, so far 3 out of 8.