LB7: Bad Injector??

[durallymax]

Well as some know i have a very rough smokey idle that pops and such.

After further investigation, i found that shutting off injector #2 cured the issue.

I checked the balance rates once more and it was out of spec +5.23 in park.

#3 was also out of spec too at -4.47.

I did not take the time to get it up to operating temps but im pretty well set on that #2 injector being the culprit.

I took it to the dealer the other day to have them check the return rates and they said my fuel pressure regulator was bad, and it was throwing overboost codes. The mechanic was gone so I just took my truck and left.

I had it on the stock tune so it was obviously throwing all sorts of codes.

Im not sure what he did to diagnose the pressure regulator, if he just looked at the codes, well then i would assume it was throwing them because it is modded.


I just want to make sure that it is an injector before i tear it all apart, Im 99% confident it is, but want to be 110% before i dig that deep into it.

And then there is always the chance that i replace it and it doesnt cure the issue and something bad has happened to that cylinder.

thanks guys.

 

[fast03]

don't know about the popping, but the balance rates are telling you its bad injectors.

 

[durallymax]

or somethin bad internally.

I guess ill order two of them and tear into it this weekend.

do i need to replace the cups as well and will i need the special tool??

 

[TrentNell]

or somethin bad internally.

I guess ill order two of them and tear into it this weekend.

do i need to replace the cups as well and will i need the special tool??

it might be worth it to do a compresion check before you tear it down , just to rule out low compression on that cylinder .

 

[durallymax]

I think I might just do that to make sure.

If i get time, tonite i want to get it up to temp and test the balance rates in drive. The last test was cold in park which ive been told isnt as accurate.

Ill do a compression check soon too hopefully and then start tearing it down.

Maybe make a writeup for it too

 

[SDP]

or somethin bad internally.

I guess ill order two of them and tear into it this weekend.

do i need to replace the cups as well and will i need the special tool??

Shouln't need to replace the cups, just use a twisting motion when you pull them out of there and they should stay in. The first injector I took out brought the cup with it, I just replaced the two o-rings, put it back in and called it good. I used a L shaped allen to hook under the injector and pull up while I twisted, worked just fine.

 

[rgullett83]

it might be worth it to do a compresion check before you tear it down , just to rule out low compression on that cylinder .

X2, balance rates can be off due to low compression. As long as injector cups do not come out with injectors you should be just fine. I usually just use a pair of vise grips to twist the injector as I am pulling it out, instead of the injector removal tool.

 

[02freighttrain]

If you decide to change an Injector. (Hopefully it is on the passenger side) then this is a suggestion. Replacinig the injector cup properly is critical. If you pull a cup with the injector, it must go back in clean with "Red" Loctite on the mating surface areas. Put the cup in, then rapidly install the injector and get the clamp on it as soon as possible. Of coarse, change the O-rings. A new copper washer on the bottom of the injector is more insurance. Not a fun Job, but with your Bal rates, it points to a bad injector. Might want to try a big dose of ATF in the fuel before you jump into the change. Sometimes a shot of lube will correct Balance issues. Can't hurt. FWIW

 

[durallymax]

Okay guys, thanks, I knew about the loctite and copper washer, just wasnt sure how difficult they were to remove. Ive had it all tore apart but didnt pop the injectors out.

I may try the ATF to see if that will at least fix the one on the drivers side, I really dont feel like tearing into that side