5.3 Speed Density Tune?

[LSX420]

Hi I'm about 3 weeks into learning HP tuner software. The truck is a single cab 5.3, long tubes, 3" Y pipe, series 10 flowmaster dump and a small cam. First thing I noticed after I purchased this truck was it had no MAF sensor and what looks like someone installed a MAP sensor. From my research this was tunned to Speed density and can be a struggle to tune properly. The truck runs rich at ideal and actually runs pretty good on the street but seems like it almost wants to stall while coming to a stop but never has but once while shifting to reverse. I really just want to know if someone took the time to really tune this truck or was it a rush? One more thing is that the guy said it use to have a 4.8L in this truck but swapped for a 5.3 but the file is still 4.8L. Other than that its runs pretty damn good

[Alvin]

It doesn't look like a good tune at all. It also looks like they were tuning around a weak fuel pump or maxed injector.

[LSX420]

This is a better scan with more channels

[twenglish1]

I'm relatively new to this but just taking a quick look that tune looks like a disaster. Also appears there could be mechanical issues, or it could have to do with the displacement configured wrong, i would start there, correct configured engine displacement, confirm what injectors are installed and correct injector vs kPa table if needed. Would be worth it starting with a stock file for that truck/engine combination. Seems to be minor modifications, i would think it should run off a stock tune, unless there are mechanical issues they were trying to fix with tuning.

[twenglish1]

Looks like you are having issues with your bank 1 o2, dropping in and out of closed loop, and very little voltage change on that sensor, also will need to confirm proper fuel pressure at fuel rail.

[tana99ss]

So im guesing the vehicle was once turbo'd or something? I would start here, open and compare to your current tune, you can see i changed the ve table back to stock and a few more little things.

i would also suggest confirming the part # on the injectors. sd1.0.hpt

[SiriusC1024]

This is a better scan with more channels

You need a new fuel pump and filter.

[edcmat-l1]

The bank 1 O2 is an open circuit most of the time. It only gets pulled down, it never goes up. The bank 2 O2 works, kind of. I'd put 2 new sensors in it and pay close attention to the connectors, especially bank 1, and look the wiring harness over real good.

At one point in the log it looks like they may be crossed, but need to have 2 proper functioning sensors to be able to tell that.

You also need to put a fuel pressure gauge on the rail and make sure you have proper FP.

Did not look at the tune file.

[LSX420]

Thanks for the help. im going to change the fuel filter and check psi afterwards. I did inspect the o2 sensors and didn't see anything wrong with the harness. I do have a o2 bank 1 heater fail but I have good continuity across the coil and a good fuse. Guess I'll just replace both with Denso sensors

[twenglish1]

You should have battery voltage on the two heater wires for O2 sensor with key on, recommend test light over a volt meter as it will put a load on the circuit, you might see 12v with a meter but it will drop off if wire connections are corroded or damaged. If you are saying good continuity across the heater of the sensor, i would be leaning more towards damaged connectors or wires.