My money is it being on the injectors. I took a significant hit on my gas mileage with the Bosch 1000cc injectors. Same thing blackGMC reported. I'm not sure if its due to the size of the injectors or the fact that they're reworked from the original flow rates of around 50 lbs/hr.

 

I bet they just arent efficent at such a low pusle width. My tahoe idles at about 3% my truck cruises down the road at about 3% on the injectors.
I took a lil hit when i went to BR7EF plugs and these 84 or 91# injectors.. cant rem what they are haha.

 

But if it's still running at stoich with no increase in airflow, that should mean the fuel economy will be the same at the same speed, it's basic physics/math (or whatever field you want to call this).

If the injectors are too big and inefficient at low pulse widths, that should show in the NBO2 readings as not stoich I'd imagine.

The only thing I can think of that's happening is fresh air is getting into the exhaust before the NBO2's, so it thinks its running lean and adds more fuel to make the NBO2 readings show stoich. But exhaust leaks in my experience let exhaust out not in. So I continue to be baffled

FIC is sending me a new set of injectors and data in order to rule out the injectors as a cause. Talk about service!!

 

Yea Jon at FIC is good at taking care of his customers.

 

Awesome, yeah, Jon is good people

 

That is pretty cool of them. I'll keep an eye out to see what you find out

 

I'm really beginning to wonder if this is just a technical "glitch" with the PID rather than a true finding, in my case. I wonder if the IPW can not register as low as the factory injectors I was using prior causing a false low MPG readout. My PID is showing about 3 mpg city and 7-8 highway. I know for a fact before the injectors my highway MPG was 12-13 with Dephi 44 lbers. I just dont see mileage dropping that much given that AFRs are relatively stable. I dont use o2 sensors so that's out. Anyways, I just filled up a full tank today and will see what the hand calculated numbers are. To get anything decent is gonna require me to keep my foot out of this thing since I finally have it going WOT now. The 10.5:1 LQ9 on 8.5 lbs is a handful on the street so far!

 

I thought so too, but the actual fuel economy that I calculated at the pump is significantly worse than before. It also smells like its running pretty rich.

 

Which wideband o2 are you using? I used to have an Innovate LC-1 and IMO it was a POS. The NGK AFX I'm using now is superior.

 

It's a Prosport wideband, which has good reviews but its not common among the LSx community. I sent it back for repairs and ordered an AEM wideband instead. I would have done the AFX but wanted a 2-1/16" gauge.

The truck also sometimes stumbles pretty badly between shifts. I'll be letting out the clutch and pressing on the gas and nothing will happen for a split second, then it will pick its self up. Doesn't do it all the time, but today it did it pretty badly, took 1-2 second before it responded to the gas pedal. Not sure if that is indicative of a rich condition or not. After letting off the gas it stays pretty rich for awhile before finding stoich. You can see it in the log I posted.

At low TPS my bank 2 fuel trim is much lower than bank 1. With the turbo kit the bank 2 sensor reads the combination of bank 1 and 2. I attached another log from the drive to work this morning.