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Nnbs injectors causing truck to run bad???

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Old 12-03-2017, 04:50 PM
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Default Nnbs injectors causing truck to run bad???

I put some Injectors in my truck from a 09 silverado and went ahead and switched the pigtails from the older injectors to ev6 style just getting ready for my new injectors to come in.well now the truck runs real slow it dosent have the power it used to and dropped. 5 in the quarter mile!Is there something different from the old injectors to the new ones?I looked up the part numbers and there both 24 lb injectors?I used a test light and I'm getting a pulse from all my pig tails so I know there good.Any idea why that would happen?
Old 12-03-2017, 06:56 PM
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What injectors are they?

GEN 4 stock injectors are going to be larger than 24lb/hr at 58psi.

Of the couple of 09 tunes I looked through they are 29lb/hr at 58psi and the GEN 3 P01 and P59 use a base of 58psi for the IFR table. GEN 4 IFR tables will show 25lb/hr at 3 bar and 29lb/hr at 4 bar.

Talking non flex fuel vehicles here too, flex fuel truck injectors are around 38lb/hr.
Old 12-03-2017, 07:23 PM
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Originally Posted by FFDP
What injectors are they?

GEN 4 stock injectors are going to be larger than 24lb/hr at 58psi.

Of the couple of 09 tunes I looked through they are 29lb/hr at 58psi and the GEN 3 P01 and P59 use a base of 58psi for the IFR table. GEN 4 IFR tables will show 25lb/hr at 3 bar and 29lb/hr at 4 bar.

Talking non flex fuel vehicles here too, flex fuel truck injectors are around 38lb/hr.
I just looked up the part number off the injectors and that's what I was seeing in the pics I'll post pics of the injector,Its the only thing I changed and I can feel it's slower the quarter mile shows it to.
And here is my gen 3 injectors
Old 12-03-2017, 07:50 PM
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So no tuning was done?

If so that is your whole problem, the injector flow rate will need to be changed for the larger injectors and the VE and MAF need re-tuning for the larger injectors.
Old 12-03-2017, 08:06 PM
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Originally Posted by FFDP
So no tuning was done?

If so that is your whole problem, the injector flow rate will need to be changed for the larger injectors and the VE and MAF need re-tuning for the larger injectors.
damn I got some mis information on those part numbers and or I misread.Ok well good now I can stop staring at my truck trying to figure out where I went wrong.thanks a lot for the response and help man.Im on a SD tune but yea without the retune it will just not right I'm guessing?
Old 12-03-2017, 09:06 PM
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If you put in larger injectors and didn't tune then you are dumping tons of fuel and the calculated air mass will be wrong all of the time.
Old 12-03-2017, 09:35 PM
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Originally Posted by 2002_Z28_Six_Speed
If you put in larger injectors and didn't tune then you are dumping tons of fuel and the calculated air mass will be wrong all of the time.
yea I read on ls1tech somewhere the nnbs injectors were 24 lb and so we're my originals i got some bad Info somewhere along the way but yea it all makes sense now
Old 12-04-2017, 06:42 AM
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Originally Posted by Shtbox
yea I read on ls1tech somewhere the nnbs injectors were 24 lb and so we're my originals i got some bad Info somewhere along the way but yea it all makes sense now
Yea, that's BS. Damn near all of the NNBS trucks are FF, or capable of FF which means they have the larger injectors.
Old 12-04-2017, 03:18 PM
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Originally Posted by madmann26
Yea, that's BS. Damn near all of the NNBS trucks are FF, or capable of FF which means they have the larger injectors.
Yea I prob should of payed more attention it really does make a big difference without the right tune for the injectors
Old 12-04-2017, 06:20 PM
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Just soldered my stock Injectors back on my truck and it's back to melting tires!lesson learned thanks for all the help guys guess I jumped the gun in between retunes.guess I gotta do it all the day before or day of the retune.luckily I work at lkq and injector pigtails are pretty much endless there



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