balance rates, injectors going?

[Foreman00081]

just checked my balance rates both in park at idle and in drive, here they are,

at idle in park// //at idle in Drive

1. 3.2 / 5.2
2. 2.9 / 4.8
3. 3.4 / 4.8
4. 3.5 / 5.5
5. 2.4 / 4.8
6. 3.3 / 5.1
7. 3.5 / 5.3
8. 3.5 / 5.2

last time i checked them they were all lower than they are now, that was a few months ago when i first got the ATS tuner but lately ive been noticing less power which im sure also has some to do with my fuel filter being a bit overdue for changing. not getting any white smoke, only smoke i get is dark black but it does seem to blow smoke with less throttle then it did before. also when the boost does kick in sometimes the truck just feels flat not pulling hard like it did before. also no sign of diesel in the oil but ive only checked the dipstick so far. so what do you guys think? am i on my way to needing injectors or is it still too early to tell? as far as i know they are still original at almost 118K.

 

[WanaDmxSub]

There high but still with-in spec.
Low power is a symptom of bad injectors.
Keep an eye on them.

 

[Foreman00081]

is it over 4 thats out of spec? and what is the spec in drive?

 

[whitetrash21]

+/- 4 in park, +/-6 in D ..... like lawrence said, they're still within spec but they are gettin close. keep an eye on them....

 

[Foreman00081]

thanks guys, ill start checking them more often. i did reset the trans last night and that made a huge difference. truck feels way more powerful now, i have been driving it slower than normal due to the fuel prices lately so it must have learned that and thats part of why it was feeling sluggish. shifts feel nice and crisp again just like when i first got it back from eric's and the low end power seems to be back so im much happier today. also if its not downpouring again today im going to change the fuel filter cause i know its way overdue and probably robbing a little power also.

so heres another question, when the rates do start getting out of spec at what point do i take it to the dealer? should i wait for multiple injectors to be running high? id like to make sure that they replace all of them if at all possible so i only have to mess around with it once cause honestly the dealer is about the last place i feel comfortable having my truck worked on.

 

[MACKIN]

Most dealers wont do anything just based on balance rate. You didn't add the +/- when you reported the rates. What you need to do is look at fuel return rate.

If the reading is on the + side the FICM is adding fuel to control a stable idle. If it's on the - side the FICM is pulling fuel away to control a stable idle. It's readings on the - side you have to be concerned with on balance rates because more than likely one or more are seeping (leaking).

This will ultimately led to a high fuel return rate which is what GM looks at for replacement of injectors.

 

[stacks04]

depends on where you bring it

 

[Foreman00081]

Most dealers wont do anything just based on balance rate. You didn't add the +/- when you reported the rates. What you need to do is look at fuel return rate.

If the reading is on the + side the FICM is adding fuel to control a stable idle. If it's on the - side the FICM is pulling fuel away to control a stable idle. It's readings on the - side you have to be concerned with on balance rates because more than likely one or more are seeping (leaking).

This will ultimately led to a high fuel return rate which is what GM looks at for replacement of injectors.

thanks mack, ill have to check them again but i dont remember seeing +'s or -'s so either my tuner doesnt report them or im thinking they are +'s. also i still havent found any evidence of fuel in the oil and im not getting any smoke on startup or at idle so maybe im in better shape then i thought.

and while were at it, when i check the rates should i reinstall the stock tune or is it ok to check with a big tune loaded? didnt know if it made a difference so i left the tune loaded when i checked last night.

 

[MACKIN]

thanks mack, ill have to check them again but i dont remember seeing +'s or -'s so either my tuner doesnt report them or im thinking they are +'s. also i still havent found any evidence of fuel in the oil and im not getting any smoke on startup or at idle so maybe im in better shape then i thought.

and while were at it, when i check the rates should i reinstall the stock tune or is it ok to check with a big tune loaded? didnt know if it made a difference so i left the tune loaded when i checked last night.

The tune shouldn't matter unless someone has changed the idle parameters.

But none to less you should return to stock and check as that is the way you'd be bringing it in for service if need be.

In addition if you're running a heavy dose or doses of additive this can also pooch or hide actual results as the additive adds lubricity.

Best to run a few tanks through with out additive. Get a true reading and if you have concerns have it documented at your servicing dealer. Although you have plenty of time left in years on your extended warranty I have no idea where you are at as far as mileage goes.

Good luck.


Edit: Oops your at 118k. But check it out!

 

[MACKIN]

depends on where you bring it

True dat! :thumbsup:


But he's many miles from you guys but it's be worth the trip IMO!

 

[Foreman00081]

sounds like stacks has got the hook up? are you a tech? hell i had TJ Lance haul my truck all the way to Eric's for the tranny so why not take a little trip to CT for the injectors! at least id have somebody i could trust working on it. i havent had any service done at any of the dealers in my area, i try to do anything i can myself and from talking to a couple service managers around here they dont seem to have all that much knowledge of the dmax. i had to laugh at the one chevy manager who told me he had never really seen a pump rub case and that id have to take it to a GMC dealer cause "maybe its a GMC problem". just laughed, shook my head and walked out after that.

 

[stacks04]

i cant warrant them on a gmc unless you happen to be driving near us and the truck just happens to break down on the highway, and it just happens to need a tow to a dealer because were the closest. hint hint hint.

 

[MACKIN]

sounds like stacks has got the hook up? are you a tech? hell i had TJ Lance haul my truck all the way to Eric's for the tranny so why not take a little trip to CT for the injectors! at least id have somebody i could trust working on it. i havent had any service done at any of the dealers in my area, i try to do anything i can myself and from talking to a couple service managers around here they dont seem to have all that much knowledge of the dmax. i had to laugh at the one chevy manager who told me he had never really seen a pump rub case and that id have to take it to a GMC dealer cause "maybe its a GMC problem". just laughed, shook my head and walked out after that.

If IF you were unfortunate to break down near the dealer that Stacks04 is employed by I can and WILL vouch for that particular dealer as having a EXCELLANT Duramax tech and service department!

If you need any other info feel free to PM me or Stacks.

I have no affiliation with the dealership with the exception of being on the receiving end of EXCELLANT warranty and general work performed there as a customer.

Yes I even pay to have my truck worked on there OUT of warranty also and will as needed!

 

[Foreman00081]

wow, thats quite the vote of confidence! and note taken Stacks, thanks guys, i will def keep this all in mind when it comes time.

 

[SfcJones]

are you sure - numbers are bad....my new injectors were giving out - numbers at idle, I have 80k miles on them and EFI live reports negative numbers..