Looking for advice on KR 02 silverado stock 5.3

[severancej]

Hello I am new to the forums and to using hp tuners. I have been searching and studying as much as I can about this KR I get in part throttle. I am going to try and post a log and tune file for the first time so bear with me.
If anyone has any pointers or advice please do say so.

So far ive changed PE settings, zeroed burst knock rpms, zeroed my timing modifiers and raised my min. timing along with some trans settings ive changed.
I get some knock and I feel like the timing and engine setup shouldn't be knocking but I'm to inexperienced to say for sure. my next idea before messing with base timing or knock sensors setting was to splash in some 93 octane and see if that helps? log tune 4 2.hpl silverado tune 4.hpt G8.cfg

[Rigo_eff1fitty]

your timing is not that hi to really run 93 oct. but should remove the knock. unless you have exhaust hitting the body of your vehicle

[Jason B]

It's running lean. Whats your fuel pressure look like?
Is this in a silverado?

[severancej]

Yes it's a Silverado
I have a pressure gauge test kit at home I guess I could hook it to the fuel rail under the hood? And start it up and report back my findings on that.
Oh and where is it running lean? One spot or everywhere? How are you able to tell that? Using the LTFT's?

[Jason B]

Yes it's a Silverado
I have a pressure gauge test kit at home I guess I could hook it to the fuel rail under the hood? And start it up and report back my findings on that.
Oh and where is it running lean? One spot or everywhere? How are you able to tell that? Using the LTFT's?

Yes the fuel pressure test port is under the hood, a plastic cap on the passenger side of the fuel rail crossover tube.
Theres also a vacuum referenced fuel pressure regulator, pressure needs to be read with the line connected and disconnected, engine running. Not sure of the exact specs but my stuff new was 50psi running, and 62psi running, vacuum line disconnected.

I just see the LTFT's positive says it's running lean. Why is anyones guess. Could be a dirty MAF I guess. Everyone is different, for me I have a fuel pressure test gauge handy and it takes 5 minutes max to check it.

[severancej]

Ok turns out I had an oil/trans pressure gauge. I bought me a fuel pressure gauge kit and checked it. My KoEo pressure is 55psi , idling is 50 and revving gets 59. It holds good pressure after key out as well.

[IARLLC]

Is the hose long enough to run it up and tape it to your windshield for a quick full throttle run? If not you can always get a daring friend to watch the gauge while you power-brake it It is most important to find out if your volume needs are being met.

[severancej]

Ok i did the power brake deal and at idle I'm at 50 and power braking to~1900 I'm rising to 55 for art least 20 seconds I did it. Twice

[IARLLC]

You actually ended up way rich from 2400 to 3200 at full throttle. You were WAY rich during that KR you see at 7:32.45 in your log. Your PE and MAF will need some adjustment for sure...and getting your VE table really accurate helps quite a bit too as transitions are based on that info and your computer really needs good info to be able to fuel properly as you get on and off the gas and load changes. Many suggest tuning the VE before your MAF. Either way, you will benefit from both.

Well your MAF needs fuel added. I would start by adding about 3% from 0 up to about 4625hz and 4% from there up to about 5750hz then 5% from there up to about 6750hz then 6% from there up to about 7125hz then 7% to the end and use the smooth function to blend it. That should help a bit. When the system sees that you are lean under closed loop it uses its best guess to add extra fuel when you go into PE. In your case the system is adding 7% when going into PE. Once you get your MAF sorted out you can start to adjust PE EQ Ratio up or down to end up with desired numbers. For now I would also raise the PE Enable MAP to 70 or 75kpa and set the cold pedal to move gradually from about 80% throttle at 0 rpm down to 50% throttle by about 4000rpm. There are lots of ideas about what is best but you are going into PE any time you reach 50% throttle....not much benefit and spending a lot on gas.

I also think your rig should be able to handle a lot more ignition but if the fueling is way off it will have a tougher time taking it. Also, do you know if it might have a carbon build-up on the pistons. There are a few options out there that help with that. I like Seafoam. Good luck!

[severancej]

Thanks for the direction. Idk how my pistons look it's got 225k miles I'm sure their dirty but I definitely beat on it often so idk if the old saying blow the carbon out works but I sure do lol.
I'll do some seafoam though I've never used that before but heard about it.
I changed my timing table to match stock with a little bump in the low rpm high throttle area. And I put my afr spark correction back to stock and took a tiny bit out.
I also changed my eq ratio table to mimic a stock curve just slightly leaned out.
I splashed about 7 gallons of 93 in there as well. I'll post up a log in a few. silverado tune 6.hpt

[Xr650jkallen]

Can you hear it pinging? If so what side?

[severancej]

Heres a log after the changes I made to the maf curve I think it got my ltft pretty close.

ill listen for any noise, it does seem to show KR on transition into a PE mode that's not like full WOT

A full on WOT run wont show any KR at all

log tune 6.hpl

[Xr650jkallen]

I chased and chased kr on my 01 sierra 5.3. Mine ended up being the cats clogged up.

[IARLLC]

I agree. The KR kicks in as it goes into PE. And even though it is commanding 12.12 it looks like you are getting more like 11 AFR to be honest.

Two suggestions:
Since you don't get KR during WOT, I would raise the PE throttle enable by about 10% in the lower RPM and see what you get. Maybe it will clean up the transition.

Also would try to tune the MAF up just a bit higher in the HZ range. At 7375hz, 7500hz, 7625hz, etc it is adding 2-3% in open loop which throws off all of your open loop fueling. If you can get some smooth runs up into that range without open loop you might need to add just a bit more to the MAF up there.

Also, maybe I mentioned before but I have had situations where getting the VE table really good took out a lot of KR. Good luck!

[severancej]

ok here is my attempt at modifying my tune to log and make changes to the ve table using stft.
from the graph VE stft I am gathering I need to add those stft to my ve numbers and then do another log and see what it did?
log ve tune1.hpl silverado tune 7 ve tune 1.hpt

[Jason B]

I wonder if tuning to compensate for 225000 miles of wear is the right thing to do. It should run good with the stock tuning unless there was a problem, seems theres a problem.

[severancej]

Theres no problem with the truck that I know of. The KR may or may not be real detonation at this point I'm learning how to figure that out.

I just want to know if I'm doing these processes correctly so I get them down, the truck ran fine before I got the software so I'm not trying to fix anything.


Here is the change I made to my VE table. silverado tune 7 ve tune 2.hpt