How can I test the COPS on my F150?
 

If you remember my thread about my F150, the engine was misfiring, but cleared after I took it the indy shop. Well, the misfire is back. I have new COPS to install, but before I do, can I test the old ones? I was going to wiggle the wires going to each COP and see if it cleared up. Anything else I can do?

Does the misfire only occur under load? Low RPM lugging the engine misfire?

Have you looked at the boots that cover COPS? Are they dry and cracked, or oil soaked? It doesn't take much to get them to short to the head.

I cleaned them when replacing the plugs. They had oil, etc on them.

Perhaps I can pull them and clean everything up again and install the new ones.

I'll pull the codes tomorrow. Right now all I've been told is that it's misfiring.

I guess Sun 'scopes are out of fashion?
Jim

If it stored a misfire code, then you are golden, just pull the codes, and that will tell you which one is misfiring. If your scanner can watch live data, you can also pull up misfire data, and watch the counters . Some early ford trucks did not support this however, not sure what year it came on board, maybe 2003/4 ish?. You may have to brake torque the truck a little to simulate a load.
If you have a bad misfire such as the cylinder is dead, and you have a rough idle, you can find it the old school way, and just unplug each coil one at a time to see which one has the least affect on idle quality .
I find the early Fords without misfire data, to be the hardest to pinpoint an intermittent misfire under load . I have gone as far, as unbolting, and lifting l the coils, and using a light misting of water on all the boots, then out for a test drive to try to simulate the miss .

Do you have a temperature gun?

If a cylinder is not firing or isn't firing well, the exhaust manifold coming from that cylinder will usually be colder. If it's just a slight miss there may not be enough delta T to notice.

OLD SKOOL!

Good ideas guys. All I have is an OBD plug in reader. If its as bad as it was last time, it was misfiring at idle on up. Had to be more than one coil it was so bad.

Code came up with P0307, which is a misfire on the number seven cylinder I believe. I installed a used COP the when I changed plugs, and it seemed run good.

Wiggling the wires to the COP didn't make any changes. Getting to it to pull while running without removing things is difficult.

Anything else to look at? Or just swap in a new one?

Back of engine
|-4--8-|
|-3--7-|
|-2--6-|
|-1--5-|
Front of engine

Replace it. On my Expedition the OBDII was always right.

Well, I go to work on it and it's running good. No codes now.

I replaced COPS 1-4 with new MotorCraft because light is fading and I can do them quickly.

Tomorrow I'll do 5-8. Maybe throw new fuel injectors on 5-8 since I'm in there and it takes longer

EDIT Maybe not. They are $70 each. OUCH!

I would not do the fuel injectors. Someone may disagree, I don't believe they fail very often. The COPs do though.

I agree, I cannot ever remember having to replace a fuel injector on a modular ford motor. COP's, on the other hand, are a daily occurrence. #7 is the hardest one to get at too. It is under both pipes of the fuel rail . I think you have to rotate it 180 deg. then you can twist it, and pull it out. Good luck ! Merry X mas

I miss my Expedition. I don't miss the 4.6 engine..

I replaced the coils on 5-8 and now have a P0352 code with a Service Engine Soon light!

It was running great yesterday! Grrrr....

EDIT: Checked the number two coil and the the connection was loose. It won't snap in place, so I had to zip tie it.

Also, noticed that there is little bit of coolant at the number five coil, which must be coming off the upper radiator hose elbow. Hopefully it's that and not the crossover pipe, which is secured from below the plastic intake manifold. Five year old tires are drying out, but have plenty of tread. All tie rods need to be replaced, as the boot are rotted.

With 210k, she just needs some love now and then