Just fired up my Sloppy Silverado, barely idles + pig rich

[nsogiba]

Just fired up the truck for the first time after the winter build, the basics are 4.8/SS2/80E 80# injectors, billet 7875, factory 02 return fuel system. Truck won't idle worth a shit, sounds like it's missing on a couple cylinder (probably because it's so rich, AFR pegged at 10 flat idling, needs 20% throttle just to stay running). Tune and log posted. I copied over almost all the parameters from Matt's,

First start.hpl

Stepslide Turbo 80E 3bar.hpt

Thanks in advance for any help!

Build thread posted here for more info:
https://ls1tech.com/forums/forced-in...rbo-build.html

[kevin87turbot]

Something is going on with your MAP sensor. It's stuck at 105 kPa. Are you running the proper 3 bar MAP sensor?

[5FDP]

Sometimes copying information will bite you. I like what Matt does but far too often do things not work correctly because of a difference in parts used and people don't think of that.

The log shows your MAP sensor is pegged at 105kpa, that should be a dead give away that something is wrong. You never said what MAP sensor you bought and clearly the settings in the tune are wrong for the MAP sensor you have.

The injector flow rate needs to match the fuel pressure you are running. If the injectors are rated at 43.5psi but the vehicle is running 58psi, the information is wrong.

What injectors are they? (sorry wasn't going to go through the whole build thread to see what you bought)

Power enrichment and boost enrichment will still need to be setup too.

[nsogiba]

Something is going on with your MAP sensor. It's stuck at 105 kPa. Are you running the proper 3 bar MAP sensor?

No, it still has the stock MAP sensor in it (1bar?) Have not yet installed the 3bar.

I did see 99-100 KPA on the scanner before firing it up. I think it would run fine with the stock MAP unless the scaling is way way off. I plan on running this thing with the charge piping off and driving it around NA to work out the bugs before I get into boost.

[nsogiba]

Sometimes copying information will bite you. I like what Matt does but far too often do things not work correctly because of a difference in parts used and people don't think of that.

The log shows your MAP sensor is pegged at 105kpa, that should be a dead give away that something is wrong. You never said what MAP sensor you bought and clearly the settings in the tune are wrong for the MAP sensor you have.

The injector flow rate needs to match the fuel pressure you are running. If the injectors are rated at 43.5psi but the vehicle is running 58psi, the information is wrong.

What injectors are they? (sorry wasn't going to go through the whole build thread to see what you bought)

Power enrichment and boost enrichment will still need to be setup too.

Siemens Deka 80lb injectors

I read that the Injector flow rate needs to be 94.6 lb/hr for those injectors based on many threads of people asking the same question. Also, I'm not totally sure on the offset vs volts vs vac table.

[5FDP]

Return to stock MAP settings then.

It's running 3 bar MAP setting, throwing everything off.

[kevin87turbot]

It won't run with the incorrect MAP sensor calibration. Just enter the stock info...94.43 and 10.33 for the MAP linear and offset data. That will get you going with the stock MAP sensor...
Or, even better yet, install the 3 BAR MAP sensor.

[nsogiba]

Map sensor linear should be 94.43 kpa and map sensor offset should be 10.33 kpa as taken from stock 4.8 tune. I'll upload that tomorrow and try it out. I gotta get the 3bar map on order. Thank you!

[nsogiba]

Ok, that worked a lot better. The truck found idle on its own and was able to idle fairly well, but as soon as you touched the gas it would die. Also, as it is currently in SD mode I have the intake snorkel off, and the IAC is wide open (310) causing a massive rushing of air through the throttle body. Base airflow incorrect? Log and tune attached

2nd start - IAC going nuts.hpl

Stepslide Turbo 80E 1bar map setting.hpt

[kevin87turbot]

You'll need a little more minimum airflow through the TB to keep the IAC in its proper working range.
I'd recommend opening the TB min air screw at least another full turn. What did the AF ratio look like after it warmed up?

[nsogiba]

You'll need a little more minimum airflow through the TB to keep the IAC in its proper working range.
I'd recommend opening the TB min air screw at least another full turn. What did the AF ratio look like after it warmed up?

Ah yes, I haven't messed with an LS DBC throttle body since 2013. If I recall it's a torx bit to open up the set screw for the TB. Is there anything to be altered in the tune for the new cam? To be honest I wasn't watching the AFR, I was just making sure it wasn't pissing oil/trans fluid/coolant all over the floor.

[nsogiba]

Update if anyone is following along:

Thanks Doug. I did end up opening up the throttle body set screw which helped, but then I ended up getting a big startup flare. Also, despite doing the TPS reset procedure it was still showing 6-7% TPS after the reset. Once it was idling somewhat steady around 850rpm I let it come up to temp and the wideband was reading dead lean, so I assume it needs some fuel in the VE table in those areas. (.2g/cyl and 400-1200rpm)

Of course it started pissing PS fluid from a rusty line when it got warm so I have tore the front accessory drive down and have a pump on the way. This weekend I should really be able to start messing with the idle tuning. I am using this guide as a helper:
https://forum.hptuners.com/showthrea...e-(w-pictures)


In addition, my selected gear in the Scanner shows 2nd when it's in Park...this doesn't seem right.

I was expecting the sloppy tune cabinet info to be a lot closer but it's fun finally learning how this software works.