Can anyone interpret which injectors are no good according to the pics? They have all been replaced. some from ebay (never again) and some from advance auto parts. Number 5 and 8 are motorcraft injectors. Number 5 looks a little weak to me. Should I send it back as defective? Number 7 looks higher than the rest. I have done a releative compression test and cyl 3 was 1% and cyl 4 was 2%. the rest are 0%. 2003 6.0 excursion by the way. first pic is cold and the second is warm.

 

What were the FICM voltages during those tests. You could have low output voltage to the injectors when cold and once the FICM builds a little heat it comes back up to 48v allowing the injectors to function properly.
You have to check everything before assuming an injector is dropping out. Also stay with Ford Motorcraft injectors only.

 

Just looking at the cold temperature power balance graph, injectors 3, 4 and 6 are slightly weak. Warm graph looks OK.

If the truck runs OK, I'd recommend just operating it rather than replacing injectors that have service life remaining. Hooking up your IDS and getting injector performance under load will give you more information.

As mentioned, checking the FICM output when cold (like right after key-on) is a mandatory check.

Lou Braun

 

Ficm voltage is always 48.5 volts. The truck is running rough at idle and has been bucking slightly going down the road in 6th gear on flat ground.

 

Do you have a tune on the truck?

 

No. Stock.

 

In looking at I would only look at 3 & 6. 4 may be down do to 3 being down.
I have a feeling your dealing with some stiction issues.

If you look at this you can see how both 7 & 8 pull things all over the place.


I tried the Archoil and it helped somewhat but did not fix the issue.
Once I replaced 7 & 8 the idle was smooth. I think in my case the issue was
damage do to low pressure over time My truck did not have the blue spring
when I got it at 145K miles. That was one of the first things I did to it.

I think in your case after you have checked all the other things that it looks like
you have (FICM voltage) that some Archoil 9100 oil additive might help.
Also what are you running for oil right now?



Sean


6.0L Tech Folder

 

I concur with Sean. First I'd try the Archoil which should help for a year or two. Somewhere you have an injector change coming up, though.

 

Ive been running the archoil for about 1500 miles now. It did help somewhat. I am running Delo 15w40. I just replaced inj 5 a couple days ago because it was obviously bad according to the balance test. I replaced cyl 8 about a month ago because i got a cylinder contribution code for it. Both of those were motorcraft. What about cyl 7 it always seems high? That's just as bad as having a low cyl right?
By the way, thanks for the VCM, Sean. It's working good.

 

I might think about running a bit longer (2500) in miles and see what comes up.
If you have not changed injectors then maybe switching to 5w 40. You may find
that helps. But like Jack said you should plan on some injectors down the line.

Just some dirty tricks to try pre-heat with the block heater and see how it looks.



Sean


6.0L Tech Folder


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