Turbo 5.3 Issues

[RobGChevy07]

This is a Turbo Ly5 5.3 Gen 4 EBay gt45 at 4LB of boost, stock e85 injectors running pump gas 93 tr6 plugs 228/232 cam behind a 2007.5 Silverado.
The Issue I am having is once I go WOT the AFR is good around 11 but seems to choke and doesn't go anywhere almost like 2 step sounds like its hitting a limiter. drives around 13-14afr but misfires all over the place it drove fine before the turbo, haves new plugs wires and coils and injectors and fuel pressure seems good. Also the log wont read past 105kpa this is a 2 bar map sensor on the 2bar OS.
There has to be something major I'm missing in the tune any help would be appreciated this is my first SD tune.

Issues:

- Kpa not reading past 105.
- Backfires all over the place. "but sometimes doesn't and drives fine until WOT"
- WOT Chokes the more throttle you put, at 100% throttle it sounds like 2step limiter.

I've posted the log and tune file log does not have AFR but I watched them and it was never a issue it was either close to perfect or a little rich.

[5FDP]

You need to log the 2 bar MAP channel for it to read boost. But that log shows several times that is reads 112kpa but it will stop reporting at 120kpa on the 1 bar map channel so just change it.

Please read how the EQ ratio works. Like right now you have it 1.387 all the way to 1.513.

Let's do the math here. You are requesting that is do 10.58 to 9.7 AFR commanded. That is way too rich and obviously not ideal.

Where is your wideband data?

If you have to command a super rich AFR just to achieve the fueling you want, then the tune is done wrong. If you commanded 11.0 AFR the VE table must give you 11.0 AFR. If air fuel ratio is way lean or way rich of the commanded value, then you have a lot of work to do to fix that. This is where you must have a wideband o2 sensor.


The PE and BE need to be set up different. Raise the MAP kpa for PE to 90kpa, lower the pedal enable to like 30-40% throttle. Lower the PE EQ ratio to have like a 12.0-12.2 commanded AFR, so like 1.200. Then raise the boost enrichment KPA to 105kpa and set that table to command your 11.0 or more likely 11.5-11.7ish for such a low boost level.

You should disable burst knock too. The timing isn't very smooth at all, a stock like curve would be way better and just lower it way down for the area's that see boost.

And make sure that your plug gap is around .030 for light boost.

[RobGChevy07]

Thanks for the reply ill mess with some things tonight and report back and also i gapped them .025, 4LB is just until i get it driving then turn it up.

[RobGChevy07]

Alright I did everything you said disabled burst knock, stock timing curve lowered the areas with boost, changed the PE areas to proper AFR still having the same issue I'm dead set on it being a failed coil or something of the sort, its sputtering and popping all over the place even though AFR is steady when I get a chance ill post a log with AFR.
Also the only other issue I had was there wasn't a PID for 2/3 bar I even tried updating no luck but got it to read 121kpa, I read somewhere that the 2/3 bar PID might only be for 3rd gen PCMS

[RobGChevy07]

just looking at old logs and the new logs my torque and load reading seems to be way out wack doing some reading seems like if load reading are crazy the transmission does funny things which might be the reason i go WOT it stops at 3k. Just something I read thought id throw it in here.

[kevin87turbot]

just looking at old logs and the new logs my torque and load reading seems to be way out wack doing some reading seems like if load reading are crazy the transmission does funny things which might be the reason i go WOT it stops at 3k. Just something I read thought id throw it in here.

Based on the looks of the VE table, i'd say that it's going VERY rich under boost. I'd recommend installing a wideband to determine the actual AF ratio.

Here's one that I tuned a few weeks ago. You can look at the VE table in it to get an idea of the how much more fuel yours is adding, as compared to mine.

For example, at 3000 rpm and 120 kPa on your datalog, you're at 50% injector DC. That's a lot of fuel at such low boost/rpm.
On mine, at 3100 rpm and 120 kPa, it was around 18% injector DC. Since we have similar combos and the same injectors, you can see that you have way more fuel at the same boost level. You'll need to install a wideband in order to get the VE table dialed in at WOT.

2008silverado60Lwith4L80ETurbokwmod.hpt

[RobGChevy07]

Update: Fixed most of the backfiring while driving had a bad power wire still cant pass 3k rpm no matter how much gas I give it. also here's a log with AFR but it freezes 1/3 of the way but its enough to see. Also I tired using the VE table you provided it ran super lean idles at around 17-20 AFR and if you gave it gas it died, but thanks for posting that up.

Issue: cant pass 3-3.5 rpm

I got the torque reading to stop reading 850+ but the absolute load is still really high. tonight ill check plugs and coils.

[kevin87turbot]

I didn't mean for you to load my VE table. My truck had a high base fuel pressure.
I just wanted to give you a reference.
Try this tune. I made several revisions to your tune. You can load this one directly into yours.

Turbo2BarUpdate7kw.hpt

[RobGChevy07]

Thanks so much ill try it tomorrow and update you with a log.

[RobGChevy07]

Update: no log it works fine based off what you sent me it was just way too rich hurt my eyes just to drive it but now its well, what does your duty cycle look like around 6-7k rpm? mine was 108% at 6k rpm doesn't seem right but AFR showed 9.8 now 11.2 I'm almost certain the misfire is affecting the numbers I didn't change anything, said I was at 9.8 AFR then redid it now 11.2 but plugs don't come in for another week.

[kevin87turbot]

Good deal. It'll be way more fun to drive now. Those 40 lb/hr injectors will only be good for around 570hp at the flywheel, so you'll max them out pretty quickly.
The next step up are the 6.2L flex injectors. They are 50 lb/hr. PM me if you need a set. I've got a few new sets here for cheap.

[5FDP]

It's out of injector, those are small for a cammed/turbo engine.

Even if you got the AFR around 11.5-11.7 with the small amount of boost you are making it's still going to be at 100% duty cycle.

[RobGChevy07]

Update: thinking about de-capping some stock ones see how that works also I checked plugs noticed 1 off pulled the wire and yep melted a wire really bad so my numbers are more then likely off I believe I can get away with 4lb of boost but wont know till new wires come in as well. Thanks for the helps guys really appreciate it!!!

[5FDP]

No decaps, those are garbage.