Can anyone tell me how to test a C.O.P. to see if it's bad? I have a Ohm meter in hand.

 

This is usually an exercise in futility as most COP failures CANNOT be detected with an ohmmeter.

Best to swap it with another cylinder and see if the misfire follows it.

Steve

 

I'm with Steve. Put it on a different cylinder and see if the problem follows the COP

 

How can I see if it follows if I don't know which cylinder it was in the first place? I am not throwing an codes but I am sure a COP is on its way

 

Why do you say that? What symptoms are you experiencing?

 

Slight hesitation pretty much all the time at the same point upon giving it gas.

 

When is the last time you changed spark plugs?

Most of the time, the problem with COPs is actually the boot that connects to the plug breaks down yet people replace the entire thing. You can get the boot at Autozone or just about any parts store. I would pull all of your cops out, check the boots, make sure the connection is good and then check the spark plugs.

Also, is all of the rest of the regular maintenance items up to date (fuel filter, tranny fluid, air filter, etc)?

 

I just bought the truck this past winter so I don't know if they were changed by the dealer (probably not). I plan on pulling the cops tomorrow and checking the boots. I just figured since I have them off would there be a way to test the COP. What plugs does everyone recommend? Should I stick with motorcraft?

 

The Motorcrafts are the safest bet. Autolites or NGKs are a good alternates.

COP failures are usually manifested by misfires, not hesitation. I'd suspect you're on the wrong path for fixing the problem, although, like chicken soup for a cold, it likely won't hurt anything.

I'd start by cleaning the MAF sensor and resetting the PCM.

Steve

 

Some people replace all COPS when doing the tune-up (DIY) because the service interval is so far apart - up to 100k although some would do it sooner than that. Also, you will find that the price of a set of after-market COPS online is really affordable.

However, only two of the COPS/plugs are really hard to work on because of tight location, so I suggest buying two new COPS and install brand new ones on those locations, then you can keep the two used ones for spare.

Assuming this is a DIY, I will let you discover which COPS those two are

For the other 6, just replace the boots outright, after all, they may be sitting in the engine for tens of thousand of miles and you know how hot the engine can be.

Per Haynes manual page 5-5:
primary resistance = 0.3 to 1.0 ohms
secondary resistance = 6.5 to 11.5 K-ohms

I suggest you get the Haynes book.

Did plugs/COPS twice on 5.4, it's frustrating at first but it's doable, search for the topic and about techniques, tips and pitfalls (sand/dirt you have to blow-out before removing the plug, etc). You will learn what tools to prepare and how to do it right as far as torque of the plugs (very important because of XP's tendency to 'spit' out plugs.

Have fun.

 

Thanks. I like the idea of replacing the 4 and 8 COP and using them as spares and just changing the boots on the rest.

 

Which Haynes should I get it doesn't look like they have one for the 03 Expy only 97-02

 

Try running some RXP through a tank of gas. 1oz/10 gal. Your injectors may be getting clogged so you are not able to get all the fuel it needs.

 

we already put techtron through it

 

Go back to my previous post. You're wasting bandwidth...