2006 F350 4x4 255k. EGR delete, New heads last summer, 1 was cracked, New Oil cooler, Blue spring, stand pipe, dummy plug upgrade, Upgraded STC fitting. and a new Injector harness about 6 months ago.
The truck has ran fantastic up until about a week ago. Its had a hard time starting and has an obvious miss once it fires up. While cranking I get 1100 psi at the IPC and 31% at the IPR. Plenty to fire. FICM voltage is 48 and doesnt drop below 46 while cranking. And I have sync. Here is the problem.. once it fires #2, #4, and #6 cylinder do not contribute to the power balance with my IDS. All injectors pass during the self test. Scratching my head I changed the injectors. That didnt help. I swapped out the FICM with a known good one. It didnt help. I have compression in all 3 dead cylinders. Am I correct to suspect the newish injector harness? or am I missing something I should be checking?
Thanks in Advance for any new Idea's.

 

Any low circuit codes for 2 4 and 6?

Sent from my leash using IB AutoGroup

 

What was wrong with the old harness?
Do you still have it on hand?
With moving injectors not doing any thing. I would
be looking at the FICM plugs and the injector plugs.
What about swapping the old harness back in to test?


Sean

 

#4 had low ciruit.

I do not still have the old harness. I do however have a good one to try. I swapped the harness out at customer request. I am actually considering swapping the used one in and trying it. That was my next step.

 

With a DMM and the diagram for the harness you could check
to see what the Ω are to each set of coils.


Sean

 

[quote=Yahiko;14441726]With a DMM and the diagram for the harness you could check
to see what the Ω are to each set of coils.







I just bought the Big Fluke test lead kit for my DMM.. at the very least it would be a good excuse to use them!! thanks for the replies!!

 

Try and not front prove the connectors.
The probe tip can open the sockets up
and then they no longer grip with the
force they should have. Having an adaptor
pin or back probing is the way to go.


Sean

 

Just changed out the injector harness. No change. I have ran a relative compression test with IDS. all cylinders are good. any other ideas?

I have to be missing something here

 

2,4,6 are all on the left bank. Seems kinda odd that all the misses come on that one side.

Maybe a fuel delivery problem to that head. How about a HPO rail problem.

.

 

Do a bubble test. One bad copper can affect near by cylinders on the same head.

Sent from my leash using IB AutoGroup

 

I think 78fordman is on the right step. You don't need any odd tools
to do a bubble test.

Just pull the top filter and crank the engine by the starter solenoid
wire after you fill the filter base with some fuel and see if you have any
bubbles. If you do then you need to isolate the offending side and work
you way down the glow plugs to see what one is making the bubbles.
Once you find one don't stop till you check the full side. Would not want
to miss a possibility of tow having problems at this point.

To do a HPOP test your going to need the Ford Rotunda OTC 6.0L Oil Pressure
Leak Test Adapters 303-1071 and the high pressure gauge. That is if you really
need to even test the HPOP.

One crazy thought. Could the check valve in the banjo bolt be sticking? If
for some reason it was not allowing the full flow of fuel then the pressure
would drop in that head and that could give a mis-fire.


I have the black service manual and there are 2 paged of things that need to be checked
with links on what tests to make. One of the things that stood out was aerated fuel or oil
and base oil pressure. Then excessive exhaust back pressure. Crankcase back pressure.
Have you verified that EBP,MAP,BARO are with in 1.5 PSI of local atmospheric?

I toop a photo of the pages that are relevant to this issue.





Lest see if this gives you some places to look.

Sean

 

Will do the bubble test in the am. it would be my luck to change 3 of 4 and have the 4th one be the culprit.
Thanks again for the Idea's and the education.

Yahiko if the bubble test doesnt tell me anything I will go down the list of your suggestions. I will post results tomorrow.
Thanks again.
Darin

 

If you see something in the photos I posted and need the instructions on how to do
something let me know and I'll get it posted for you.


I have a PDF of all the manuals except the Black book Service Manual

Sean

 

Ok here is the long version of what I found. First there were 3 dead injectors. I changed those out. Changing them had no effect as I mentioned earlier. However changing the injectors was the right call. I unplugged all but the 3 bad ones this morning and listened for a buzz. Nothing. I grabbed a new one and plugged it into #2 injector harness and the new one buzzed. I pulled all 3 of the failed injectors back out. On inspection there was crud in the oil inlet. What had happened is the owner had installed a Dorman oil cooler. the gasket has failed and is all over in the HPOP system. I cleaned the crud out and all the injectors are working now. the truck is sitting torn down awaiting a OEM oil cooler, IPR screen, Oil cooler screen and a ton of cleaning. On close inspection the original Injectors have gasket parts in them as well. This is another DONT use Dorman parts on a 6.0 thread now. On a lighter note the truck sure ran nice before I shut it off and tore it down!!

Thank you very much everyone who chimed in and offered ideas. They led me to the cure.

Darin

 

Happy that you found the reason.

BUT! Holy ****. One more reason.

Are you going to send the bill to Dorman?

Also by any chance did you take any photos of the oil ports? Would be some thing to show around.