04 late build injector problem

[kbomb2788]

Hey guys. Got 04 6.slow (late build) after hard accel the number 5 injector would have a dead miss (almost sounds like fuel knock) yeapedy skipedy I thought it was injector (after checking ficm mpower, icp, ipr, ebp, harp, map, fuel pressure (right at 45 with valve open, don't like it but customer is cheap and it's a side job witch I don't have such good luck with). Take the old one out, found nothing wrong with it visually, top I ring is fine. I did notice the heater valve was resting on top of the# 5 harness and rubbed insulation of one of the wires, I cut and spliced it with double heat shrink. Tomorrow I'm going to check inj harness with dvom. Have you guys ran in to that, I can't get a break right now and everything simple becomes a big pain in ass. Thanks

[Aaron]

Put an injector in #5.

[kbomb2788]

That's the thing first thing I did is replace #5. After that it does the exact same thing as before. It does have an old style ficm harness. I guess I'm going to tell the guy he needs 200 harness

[Aaron]

Ah. I missed that. How's your relative compression look, as well as your click test?

[kbomb2788]

Relative good, click test good. Went to work grabbed another inj harness and still got the same problem.

[Bruce Amacker]

Swap #5 with #3.

 

[Aaron]

And if that doesn't work swap in known good test FICM.

[Keith Browning]

Actually, you might want to pull both adjacent injectors and look at everything. I recently had a 6.0L with an injector issue... somebody replaced it three times before it came to me. I did the same and it returned fairly quickly. I pulled the rest of the injectors out of that bank and discovered the copper gasket on one of the adjacent injectors was leaking combustion into the fuel rail. For whatever strange reason it had no affect on that injector which happened to be #1. It did make #3 misfire though. None of the typical diagnostic tests showed anything that would have led to this. It just acted like the injector was bad. I serviced the cup and replaced all four injectors on that bank. released the truck never to be seen again. Perhaps your #3 is blowing bubbles downstream to your #5. Just a thought.

[kbomb2788]

I'm going to run the truck with valve covers of today. I cranked the engine with fuel filter off and didn't see any bubbles. I work at a dealer that does not have a single 6.0 on a lot(i realized that when I wanted to swap a ficm, small dealer) I know you suppose to change the ink I rings when you take them out, for diag purposes can I swap them with out replacing them? Also thanks for replies

[Keith Browning]

You need to change the rings or at least the compression/ copper gasket. You don't want to create an issue while you are diagnosing one. Right?

[kbomb2788]

Hey, I couldn't get a ficm today but I ran with valve cover off and noticed oil is pouring right on top of the injectors. Now I haven't done any rail nipple o-ring but is that what it looks like. If it is what you guys charge for repair