changed from prev thread ( Injector Cleaners??) since the subject has changed....
see posts from #23-#30 on new issue

i was just getting ready to post updates..
sgII not in yet...
i am know getting constant miss even after warmed up, so i took it to mechanic last night to have him check ficm, he went to drive it and said wow this things missing bad, w truck warm, it was as 48.5 dropped to 47.5 cranking.he ran codes came up w P0237, P0272, P0403,P0480, P0528....

did injector diag, #4 was changing as low as -48 while the others remained at 0

he had me leave it so he could check it this am when cold. went over this am he hooked it up, ficm - lowest it was was47.5 cranking and stayed at abt 48.. so looks like ficm may b okay..

injector diag showed #4 #6 #7 all dropping to negative numbers jumping all over the place, he suggested we use the bg clean system, one qt treats fuel, 2nd treatment goes directly in the oil, stuff was like alcohol, let set idle for 1.5 hrs, drained and purged system, new oil filter and royal purple 15w40 and 1 qt of bg DOC, diesel oil conditioner......went and drove truck was still missing a little..

he had reset the codes earlier but the codes came back showing #4 injector, told me to drive it for awhile to work in the fuel treatment, upon driving it will clear up and run great then start the miss agn under acceleration, then clear up agn....
thats where i am to this point...this was from friday...

last night after leaving work have the same problem, missing very bad cutting out until it warmed up, then still has a miss....

same thing this am

 

Even though you're not getting a code from #1, cylinder #'s 1,4,6, & 7 are all on the same connector to the FICM. I'd check that connector to make sure it's well connected and that the ground is connected. Just because you have good FICM voltage doesn't mean the FICM isn't toast even though you're getting C/B codes and not codes to indicate a bad FICM.

 

the treatment did not solve any issue, i will be refueling this evening....
also noticing that upon start up it is giving me blue smoke while it is sitting and idling.....

any help would be greatly appreciated, we are stumpped (unless it is the injectors)

what is the correct fuel pressure??

 

Nothing less than 45psi; the higher the better. Tim suggested...and I agree...check your FICM plug to make sure it's in all the way and the FICM ground is hooked up.

 

fp was at 58...

i will have to get to him cause i dont even know what to look for, if the plug was not all the way in would it clear up after wareming up?? i called him abt ground, he said he knows its good had to put new ground ring on that wire...

yesterday morn it didnt really want to start, waited for light to go off, crank it then it would try to fire off and die, did that 3 times before she cranked up....

my tech is saying he feels it needs 3 injectors, as i have told him thats fine i just want to make sure that is problem before proceeding, he says that all the vitals are good so leads him to beleive thats our problem, i just want everything else ruled out...

heres the next thing, if it is injectors, injectors are 225 each x 3 +tax + install abt 1200 bucks......he has 125hp inj in his truck, they have 1000 miles on them, he is upgrading to 285cc/305hp inj, he will make me a deal on all 8 inj that wont be much more than just replacing the 3 stock inj....would this be a wise decision??? remembering that i have new heads, gaskets, injector cups etc.....

 

the other thing i am realizing.. before the work was all done the overhead gauge was saying 15-16 on avg, on paper it always came out to 15.8.......after i got truck back and it was runing great the overhead gauge avg was 17-18, then she started acting up so i dont know what avg i was really getting, as of right now it is registering 12.2.......ugh......

 

sounds like more then one injecotr or a harness issue. my vote goes to injectors.

 

i am going to go by the shop this evening to have him hook up to computer to check the feul pressure agn, will it be different warm than cold ???? what the range it should be, he told me it was 58 last week, just want to double check...

and he has an extra ficm there, r they all compatible?? if so i will see if we can switch it out to rule it out

 

Fuel pressure is tested with a manual gauge, not the computer. That's not possible since there isn't a fuel pressure sensor. FICM's will interchange with no problem. 58 is fine on the fuel pressure at idle, but what is it at wide open throttle??? That's where you tell the tale. If it falls below 45 you need to do something.....

 

npcc-- isnt there a sensor on the rail to tell the injector what to do??

 

no that is a function of the pcm and the ficm

 

Scanner/computer will NOT show fuel pressure.