So I have messed with 6.9 & 7.3 IDI engines for 13+ years as a fleet mechanic but now have a 2005 F550 with a 6.0 and it has problems a plenty. It runs horrible now that it does run, smokes white and has no power at all like it wont even pull up the driveway unless its floored with a running start. It has the following codes stored:
PO113 air intake temp
PO269 cyl 3 contribution
PO278 cyl 6 contribution
PO284 cyl 8 contribution
PO405 egr valve
PO 674 #4 glow plug
PO1635 ????

Now I have replaced the air intake temp sensor(PO113) the egr valve(PO405) and all the glow plugs on the left bank(PO674) and those codes are gone. Additionally I changed the oil & filter and the fuel filters and cleaned the K&N air filter though the oil and all the filters were clean I figured it coluldnt hurt. Nothing thus far has made it run any better though so I wanted to get some feedback before I dropped cash on 3 new injectors being that its not a mechanical system like the IDI there are I believe more parts to check than just the injectors so any advice would be much appreciated. Thanks!... also just incase it makes a difference it didnt run at all when I got it so I really dont know how its supposed to run.

 

First thing I would check is the fuel pressure, it needs be be above 45 PSI at all times. One item unique to the F550 is they have laminated steel tanks that are known to delaminate and plug up the pickup screen. Low fuel pressure kills injectors. You will end up replacing those injectors but you need to make sure the fuel system is healthy before you do. Doing the blue spring upgrade to the fuel pressure regulator is a must do also.

 

FICM voltage ok?

 

How would I check ithe ficm voltage, can you point me to a link or another thread where that is discussed. As I said I am familiar with the old IDI engines so I am slightly lost on the electronic aspect of the 6.0. Thanks so much for the help so far!

 

There is a FICM test procedure in the tech folder at the top of this forum.

 

I am amazed that the engine actually starts, if those three cylinder contribution codes do really mean you have three non-firing injectors. And yes I most definitely agree that it would be worthwhile pulling the fuel tank sender out of the tank for an inspection of the inner lining of the tank, along with the fuel pickup on the sender and pickup unit. I have actually seen the rubber pickup degrade and disintegrate, while clogging up the pickup tube to cause a restriction/contamination concern too, almost mirroring the exact symptoms you describe. If this is true, address and repair this issue BEFORE installing the new injectors. And when you are ready to install the new injectors, yes most definitely install the "blue spring" update fuel pressure regulator.

Checking the FICM voltage wouldn't hurt by any means, but judging by the OP's description, along with the codes set, I have a feeling the FICM is not the cause of the issue. If there were any issues with the FICM, you would almost always see P0611 and/or injector circuit codes set as well.

 

Replaced the 3 bad injectors, fuel filters and had the tank cleaned and re coated also I flushed out the lines as best as i could and boy will it run now! the code that nobody knew what it meant disappeared as well as all the other codes. Too bad I cant stand to drive it b/c the turbo pipes are leaking so bad it takes about a mile before i am gagging from the exhaust fumes. THANKS so much for the advice

 

This could be from a cracked Y pipe, or maybe the connections.

Congrats on getting it running, a little fine tuning and it's good as new


.

 

With the exhaust leaks fixed it will probably pull even harder (depending on if it's leaking before or after the turbo).