Help with TUNE

[twenglish1]

You will keep your current file with correct injector data, copy stock airflow, spark, idle parameters into your file

Here try this, Left the injector data, took most of the rest back to stock, pulled 20% from idle area of VE and smoothed because of the cam, left your rev limiter settings alone, stock spark tables, MAF still disabled, and STFTs and LTFTs are enabled. Also through this process its a good idea to periodically check the engine oil incase any of the previous tunes were ridiculously rich and flooding the engine with gas.

99_Sierra_8.1L_Injectors.hpt

[Chris miller]

I?ll look. Tried looking before and couldn?t find anything with the 5.3 with 8.1l injectors.
Stock was 24# and the ones I currently have in are 42#

Here?s a stock file from the hp tuner repository.
1042218950.hpt

Don?t know if these are correct but this is all I could find for the 8.1l 42# injectors
8_1 Marine Injector data LS1.xls

[twenglish1]

See above, i was working on the file and must have posted it at the same time you replied. I used the same stock file that you posted, kept the injector data 04silverado6.0 put in it, and took most everything else back to stock, few minor changes that should help it start with that cam

[Chris miller]

I’ll try when I get back home. Had to run up to the hospital. MIL and dad are up here. The spark tables etc that were done on the dyno, did you change those?

[twenglish1]

Yes, all back to stock for now except the injector data if you wanted to try it, the tables are still in your original files and can be added back at any time, you can even go back to the files you originally posted at the start of the thread. My thought is that we need to see the vehicle running in closed loop fueling to see whats wrong, the initial files you posted there was no way to tell being open loop and no wideband. Honestly though, thinking more about it, im sure you paid good money for that dyno tune, if i were you id load the original tune back in that you posted and i'd make them fix it.

[Chris miller]

Yes, all back to stock for now except the injector data if you wanted to try it, the tables are still in your original files and can be added back at any time, you can even go back to the files you originally posted at the start of the thread. My thought is that we need to see the vehicle running in closed loop fueling to see whats wrong, the initial files you posted there was no way to tell being open loop and no wideband. Honestly though, thinking more about it, im sure you paid good money for that dyno tune, if i were you id load the original tune back in that you posted and i'd make them fix it.

I agree with making him fix it but it will sit until he’s ready or can make time. He’s flashed it 3 times with no success in fixing the cold start. I just wanna to be able to drive my truck and not be stranded.

I’ll load the file and log , then post it.

This is the 2nd engine. Original popped a head gasket…had over 280k and decided to build a 6L. Everything was fine until it needed more injector and we swapped to 8.1L injectors. He had hell with the injector data and had #6 stick open flooding the cylinder and throwing a rod. (Didn’t even have 500miles on it). Ended up building the 5.3l that took a dump and this is where I’m sitting

And yes I paid good money for the dyno tune. As stated by 04silverado6.0, spark tables are dyno proven….it was dyno tuned with wideband installed but cold start wasn’t.

[twenglish1]

Those injectors you have in this one are OEM from a reputable source correct? And you have verified fuel pressure right?

[Chris miller]

Those injectors you have in this one are OEM from a reputable source correct? And you have verified fuel pressure right?

New Standard fj675 from Oreillys. Yes verified fuel pressure.
The fuel pump that was in was 51psi WOT on the dyno and 43 idle at the pump outlet. Swapped with new pump that matched the injectors flow. Fuel pressure regulator on the fuel rail is the stock for the 5.3.

[Chris miller]

8.1_inj_stock_start.hpl

quick log before it died on startup

[Chris miller]

p0103 pending/current without MIL

[twenglish1]

Are you able to keep it running with some light throttle?

[Chris miller]

Are you able to keep it running with some light throttle?

no, not really. spits and sputters and falls on its face. I loaded the Original edit file and logged.

original_edit_1_log2.hpl
original_edit_1_restart_log3.hpl

[Chris miller]

what i cant wrap my head around is how it runs fine with the fueling tables AFTER 110 degrees. Its only before 110. Theres gotta be something or somewhere to change that temp, no? just wish it was that easy.

[Chris miller]

AFR Commanded on startup is 6.27 and after about 6 seconds it starts to lean out to 12.1 to 13.09 until it reaches 110 degrees ECT and then richens up to AFR commanded 7.89 and idles fine.

[twenglish1]

That shouldn't even run on gas with a commanded AFR that low, 6.4 is stoich for methanol... since it is running, commanded AFR is being used to compensate for other issues with the tune. Something is wrong, add injector pulse width channels and log again, they are called Injector Pulse width Avg. Bank 1 and bank 2

[Chris miller]

just going off of what the log is showing. Im lost. its also on the OEM narrowband o2s

[twenglish1]

I am not entirely convinced this is a tune related issue at this point, i think it started as mechanical issue that was tuned to try and fix it. I would be confirming you have the injectors you think you have at this point, fuel pressure, double check for vacuum leaks, make sure injector o-rings on the intake side aren't leaking, compression check, etc... Back to the basics. I would be curious to see what the injector pulse width is doing on a log though.

[Chris miller]

I’ll log injector pulse width tomorrow. Everything on this engine is new. Fresh build with 2 tanks of fuel through it. I’ll double check everything again. Only thing I didn’t check was compression because well… everything is new.

[twenglish1]

Look at a couple spark plugs too, they always tell a story, along with making sure the oil hasnt been flooded with gas

[Chris miller]

Look at a couple spark plugs too, they always tell a story, along with making sure the oil hasnt been flooded with gas

Gonna be looking at all of them while checking compression. Break in oil was changed at 250 miles and went to 5w40 syn. Break in oil is straight oil. No fuel in it. I’ll drain and check this round also.