Spark Plugs keep fouling & P0172 code

[Mudsport96]

Do you know the manufacturer and part number of the injectors you installed?

 

[Fless]

I didn't gap the plugs - they were pre-gapped. However, I just looked up the plugs I bought and one complaint was that it wasn't gapped properly. I'll pick up a gap tool and check that.
All of the plugs are fouling about the same and evenly.

Be very careful when checking or setting the gap on platinum and iridium plugs; the firing tips can easily be damaged.

I'd also wonder if the "ACDelco" spark plugs are counterfeit. A pic or two of how they're wearing, and how many miles they have gone through, would perhaps be telling.

 

[Big Mama]

Can’t remember if I asked if there’s any oil consumption?

 

[Jerome Nelson]

Can’t remember if I asked if there’s any oil consumption?

No oil consumption at all. (yeah!)
Also, the oil looks completely normal for the milage - a nice golden brown.

 

[Mudsport96]

Are you sure the aftermarket injectors are the correct flow rating?

 

[Jerome Nelson]

Are you sure the aftermarket injectors are the correct flow rating?

That is a great question. And, honestly I have no idea.
Here is the link to the Amazon Injectors: https://www.amazon.com/gp/product/B...in_title?ie=UTF8&psc=1&tag=tahoeyukonforum-20

However, I wouldn't recommend them. I had to purchase two sets, as the first set had a couple of leaking injectors. I pulled a couple from the second batch and returned the mixed set with the two bad injectors.

I would note, that the original injectors I pulled had four holes - but the new injectors only had two. I would think that would cause more of a "lean" issue, and not a "rich", if there was a problem with that.

 

[Jerome Nelson]

Do you know the manufacturer and part number of the injectors you installed?

(replied above)

 

[strutaeng]

That is a great question. And, honestly I have no idea.
Here is the link to the Amazon Injectors: https://www.amazon.com/gp/product/B...in_title?ie=UTF8&psc=1&tag=tahoeyukonforum-20

However, I wouldn't recommend them. I had to purchase two sets, as the first set had a couple of leaking injectors. I pulled a couple from the second batch and returned the mixed set with the two bad injectors.

I would note, that the original injectors I pulled had four holes - but the new injectors only had two. I would think that would cause more of a "lean" issue, and not a "rich", if there was a problem with that.

I would not trust Amazon injectors personally. Even name brand sold by them is getting sketchy. They don't show the flowrate. Do you see where they state that?

Are you saying that the problem (rich condition) was there prior to replacing the injectors?

 

[Jerome Nelson]

I would not trust Amazon injectors personally. Even name brand sold by them is getting sketchy. They don't show the flowrate. Do you see where they state that?

Are you saying that the problem (rich condition) was there prior to replacing the injectors?

I totally get not trusting non-OEM injectors! I just couldn't bring myself to pay $800-$1K to replace them.

No, the rich condition happened sometime after the new injectors.

 

[Jerome Nelson]

I swapped an L59 engine (from a 2004 Yukon XL) into my 99 Silverado V6. My ECU was sourced from a 2000 Silverado. My base tune was the standard LM7. The truck ran around -11% LTFT on both banks, at any given RPM range. I knew what the problem was: flex fuel injectors are like 33 lb/hr vs lm7 are like 24 lb/hr iirc. Truck ran fine, except for the fuel trims. Occasionally it would throw an O2S voltage code, which was legit. I had to change injector flow rate with HP Tuners and now it's good.

I finally had a chance to run diagnostics on my Tahoe with my Blue Driver. I took a short, 20 minute trip with a mix of stop-and-go and 50m/hr highway.
The short and long trim was mostly in the -10% to +10% range - with the exception of a couple of +/-100% blips. I'd guess these would happen about every 4-5 minutes. (Please see images.)

I'm not going to pretend I know what I'm talking about. But, I think I heard that the +/-10% was normal/good. I'm not sure what the +/-100% blips are telling me. Any thoughts?