Inconsistent Balance Rates

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Blackhawk878

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Jan 16, 2012
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Grovetown, GA
What would cause balance rates to change, going from 8.1 to .1 on one injector then others flopping in and out of tolerance as far as balance rates go? I have done the fuel system cleaning in the DIY section, ice picked all the injectors and changed fuel filters. My weird circumstance is that if I have been running it for a while, 10 miles or so, check the balance rates, some of the injector show bad on my CTS. If I turn the truck off, start it back up and recheck the balance immediately they are fine or the problem has moved to a different injector.

I have no loss of power or white smoke but I do hear what I think is an injector knock. Any suggestions? FICM?
 
bluecollar

bluecollar

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Feb 28, 2012
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ia
No my injectors only have 12k on them no issues what so ever sometimes ill check it and its at 5 drive couple miles and its at 2.. then I'll look at it random and its below 1. Idk either sticky injector or maybe valve problem... urs is weird how it changes injectors I heard someone say look at the wiring for the ficm but u would think there would be a code for that if there was a broken wire..
 
bluecollar

bluecollar

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Feb 28, 2012
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ia
I hope someone can give some ideas... I haven't tried cleaner yet cause ill ask GM what they want me to do. My injectors have a year warranty but its just the 4# injector on mine and sometimes its good.. can it be bad? ??
 
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Blackhawk878

Member
Jan 16, 2012
100
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Grovetown, GA
bluecollar said:
No my injectors only have 12k on them no issues what so ever sometimes ill check it and its at 5 drive couple miles and its at 2.. then I'll look at it random and its below 1. Idk either sticky injector or maybe valve problem... urs is weird how it changes injectors I heard someone say look at the wiring for the ficm but u would think there would be a code for that if there was a broken wire..
Click to expand...

I think the wiring is going to be my culprit because I hate trying to figure out shit like that.

I just reconfirmed my findings. Checked balance rates after driving home and number 1 was ~6.9. Turned truck off, let CTS shut down, started truck back up, checked balance rates again. number 1 was beautiful ~.3. Number 4 and 8 were just over 4. Going to load stock tune next and see if that does anything for it.
 
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Blackhawk878

Member
Jan 16, 2012
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Grovetown, GA
I'll check with EFI Live and see what I get. There was discussion of tunes affecting balance rates (or perceived balance rates) somewhere, not sure if it was this forum or another. Could there be any truth to that? Don't want to waste time flashing the stock tune if it doesn't matter.
 
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Blackhawk878

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Jan 16, 2012
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Grovetown, GA
So efi live is giving me similar results. From my logs it looks like #1 is bad with 3 and 7 not far behind. Could it be a normal symptom of an injector going out that on start up it is fine until throttle is applied? What are symptoms of an FICM going out?

I also reloaded the stock tune and it didn't change anything in the balance rates.
 
xcablb7

xcablb7

New member
Feb 8, 2009
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Fall River
i have 3 bad ones that at one point i could switch tunes on my dsp5 and balance rates would get better or worse, adding a bottle of lucas seemed to straighten them out for a few days
 
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Blackhawk878

Member
Jan 16, 2012
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Grovetown, GA
So would inconsistent balance rates be a good sign of bad injectors?

Also, is there anything to be concerned about going with reman injectors from II instead of new ones?
 
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bluecollar

bluecollar

Member
Feb 28, 2012
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ia
I got my remans from gm.. but atleast I know #4 is the problem.. if u could narrow down the worst ones and change them and see if that brings them together. This moring mine was at +5 and just now checked it again 1.8 wtf
 
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Blackhawk878

Member
Jan 16, 2012
100
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Grovetown, GA
Ya, the truck can be pain in the ass sometimes. If my garage were long enough I would have pulled all the injectors and sent them to exergy for rebuild, hone and bench flow. Most of my projects need to be completed in a days worksince I no longer have adequate storage area.

I should probably know this, but what is the worst case scenario that could happen running bad injectors?
 
05Monsterdmax

05Monsterdmax

New member
May 31, 2011
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I have a set I just got back. Efi is saying cyl 2 and 4 is 15 no matter Wat injector I put in that cyl..... Done picked them and cleaned the connections. Any ideas? All passed test and drip tests. Smokes white at idle now to
 
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