F350 6.0 Diesel misfire

Were any tests done? My first step on a diesel misfire is a relative compression test.

have yo checked the EGR to see if it is clean?

No codes Injector buss test routed out #4 injector. Replaced all with OE Reman plus harness due to mileage. This symptom is random and usually only at idle. IDS test is next for relative compression, Generic scan with Snap On, relative comp test was normal. EGR is not clean but is not in play at idle.

Please post a capture of the IDS Power Balance when the issue occurs.

Hi John I would put a pressure transducer or piezo sensor in the exhaust, intake, then starter current. Next synch off a Injector using current. You will have to disable fuel somehow or you could disconnect all the injectors and just plug one injector in but use one of the injectors you took out already and plug it in and secure it. Then crank the engine over and see if you notice anything…

hi Mike he said runs worse after injector replacement . so a good base point is to see if all injectors are working right ?? . do not u some new Never Ever Works is good . Get back to the original test point #4 . it is a ford do a koer test with scan tool and see what current ramp is when running to see what injectors health is . and then do your test . just my observation. thanks Randy

I understand where your coming from Randy and yes it is likely that he got some junk injectors however when I get into a predicament like this I like to verify the problem. In this case making sure that it still is no 4 and not another cylinder or for that matter another issue entirely. In these situations I like to rule out mechanical with a scope and make sure the scan tool isn't lying to me…

Mike john has not replied back . butt i see were you are going with this . mechanical check has already been suggested to him . i guess we what for his post

I would check compression if you haven't done that yet, relative or gauge before going any further

If you have an IDS Start with a relative compression test

Hi John, are there any codes? Like the others mentioned I would start first with relative compression. If it looks good, make sure the connectors are correctly installed on the FICM. I would also run a buzz test to get a little direction. I see you replaced the injector harness, is it perhaps routed wrong or damaged where they plug onto the injectors.

Did you replace or reuse the old injector sealing washers? I've seen people reuse old ones and it would run worse when they finished the job. Also, like everybody else already said, check compression.

Bad injector possibly. We went through 3 sets one time. Swap it with another cylinder if possible. Assuming relative compression and valve movement is the same. Make sure EGR is not stuck.

Have you checked fuel pressure and fuel aeration? It only misfires #4 at idle?

fuel aeration? How about fuel cavitation too?

In addition to everything already mentioned - relative compression, etc. With the IDS power balance screen running - wiggle the harness from FICM to engine. We have seen some harness rub through issues.

Wonder if you could also look at the opening coil current or voltage with the relative compression just to be sure it looks to be firing at the correct time.

Did you current ramp injectors