2000 5.3 LS DBC stumbles when taking off after cold start.

[TBerkenpas]

To start this out, I am a complete noob to this stuff, I know a bit, but am definitely still learning.

I have a tune file and Log of my vehicle that I just recorded, I cannot seem to figure out what is causing this. I had my file remote tuned by PatG which, truthfully, the engine runs very well and feels fairly good in all aspects, except for this issue, I just changed my TPS to see if it was telling the ECM the wrong position or something, that did not fix it. So I am resorting here to see if my file needs an adjustment to make it work better for me, I know there is someone on here with more experience than myself.

Thank you very much for your time in all who offer any help.

Tyron Berkenpas 2000 Silverado 5.3L A4 headers 87 oct 35.0 3.08 PG tune 2.hpt

5.3 LS Log File 6-24-23.hpl

P.S. this log file was recorded after the motor was warmed up, I could not fully reproduce the issue mentioned until slightly at around the 7min mark. I will record again tomorrow after engine is cold again.
It only does this when the engine is cold. Like a carb without enough choke trying to take off.

UPDATE 6-25-23: NEW FILES WITH ISSUES PRESENT
5.3 LS Current Tune 6-25-23.hpt

5.3 LS Log File 6-25-23 With Issue Present.hpl

[SiriusC1024]

Try this.

[TBerkenpas]

Should I really be putting a random tune in my engine?, don’t they each have their own characteristics?

[SiriusC1024]

It's your tune with the following:
- closed loop enabled
- STFT open loop disabled
- Open loop fuel ratio enrichened at lower temps.
- Idle speed increased for tip-in throttle transition
- Spark tables lowered for better idle, smoother transition
- Idle/park tables set to match main more closely for less abrupt transition and jerking
- Over/underspeed spark lowered for better idle
- VE tables corrected at low rpm/upper map
- WOT shift rpm's increased
- Shift torque reduction re-enabled by means of spark (you want this)
- PE set to come on at more appropriate loads

I haven't been impressed with these PatG tunes. They always need finishing touches. It'll work better now. You asked for help, so I supplied you with it.

[horsepowerguru427]

Should I really be putting a random tune in my engine?, don’t they each have their own characteristics?

SiriusC1024 is pretty knowledgeable so id try his tune with the adjustments if i were you. This forum is here to help, not sabotage people, so we're trying to help. FYI any remote tune wont be perfect. Theres always gonna be things that need adjustment. Sending data logs and the tune back to the OG tuner is the only other way to deal with problems, unless you do it on your own, but i feel like sometimes you have to be there in person to really understand the issue. Try his tune and if it doesnt help then just put your curent tune back in. problem solved.

[SiriusC1024]

Thanks man

[TBerkenpas]

Sorry for questioning you, just used to having to question everything I’m told growing up, thank you for the help man.

I’ll put the tune in tonight when I get home from work and let you know.

[SiriusC1024]

It's not a bad thing. Just illogical in this case. You asked for help idk else what to do. If I told you or showed you what difference would it make?

[Alvin]

This log is from 160 degrees ECT.. Is that what you mean by cold start?

Can you mark it on the log where you feel it? And what are the mods.

[SiriusC1024]

Show us on the doll where the bad man touched you.

Sorry lol couldn't resist.

[TBerkenpas]

This log is from 160 degrees ECT.. Is that what you mean by cold start?

Can you mark it on the log where you feel it? And what are the mods.

I feel it any time I go to take off from a stop when the motor has just been started, and only at about 1/2 throttle, maybe a bit more. On that log I made, it did it almost every time the rpm’s increase, if you go real slow on this ramp ups, you’ll see where it actually drops some RPM before going back up again.

Mostly stock as far as mods go, 4 inch intake pipe to a filter, and headers with straight through glass packs. My main issue with big is running 35s on 3.08 gears. But that shouldn’t effect engine hesitation/sputtering.

[Alvin]

A 1-2 shift with that setup would be close to 70 mph for 5600 RPM 2-3 would be 120 mph

I'd say you are just feeling how awful the truck is geared for what you have.


The truck is mostly stock and I don't see anything standing out. You are probably killing the converter trying to get the truck rolling.

[TBerkenpas]

A 1-2 shift with that setup would be close to 70 mph for 5600 RPM 2-3 would be 120 mph

I'd say you are just feeling how awful the truck is geared for what you have.


The truck is mostly stock and I don't see anything standing out. You are probably killing the converter trying to get the truck rolling.

It is quite underpowered, but I can easily hold 65 at 2100rpm in 3rd, I’ve got 4.11s I’m going to throw in as soon as I can get another vehicle off my lift.

But I don’t think it’s all the gearings fault, the engine shouldn’t sputter no matter how big a load is on the engine.

[horsepowerguru427]

Show us on the doll where the bad man touched you.

Sorry lol couldn't resist.

Show us on the log where the bad tuner hurt you

[TBerkenpas]

Try this.

Tried your tune, everything seems quite a bit smoother, thank you.

[SiriusC1024]

Sweet.