PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Turbo 5.3 possible tune issues

Thread Tools
 
Search this Thread
 
Old May 16, 2018 | 01:28 PM
  #1  
bbowerman's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2012
Posts: 111
Likes: 0
From: tulsa, ok
Default Turbo 5.3 possible tune issues

Hey guys I am going to try and break this down to make it easier to understand.
The vehicle.
2001 Silverado p01 ecu
3 bar ls1 style map from efisource
Gen iv intake with 92mm the
4l80 (separate controller)
on3 7875 turbo with fmic

The issue.
I tuned this using hptuners and so far I am running 10psi according to my boost gauge. AFR looks like it's supposed to. It ran good for the first 9-10 pulls I made at the dig spot, drove it home smoothly no issues. The next weekend when I did the pull it felt a little weak in higher boost range. And when I let out it misfires hard until I free rev in neutral then it's fine unless I try and boost again.

What I've tried
New wires/plugs
Vcm logs look okay.
coils are all firing at idle

What I'm questioning.
At 10psi it reads 135kpa
At idle it reads 70kpa
Does that seem correct? Or do I have a bad out of the box map sensor. Linear and offset where provided by efisource.

Any suggestions? Tia
​​​​​
​​​​​​
​​​
Reply
Old May 16, 2018 | 01:50 PM
  #2  
ddnspider's Avatar
10 Second Club
20 Year Member
Liked
Loved
Community Favorite
iTrader: (26)
 
Joined: Aug 2004
Posts: 14,628
Likes: 1,778
From: FL
Default

Originally Posted by bbowerman
Hey guys I am going to try and break this down to make it easier to understand.
The vehicle.
2001 Silverado p01 ecu
3 bar ls1 style map from efisource
Gen iv intake with 92mm the
4l80 (separate controller)
on3 7875 turbo with fmic

The issue.
I tuned this using hptuners and so far I am running 10psi according to my boost gauge. AFR looks like it's supposed to. It ran good for the first 9-10 pulls I made at the dig spot, drove it home smoothly no issues. The next weekend when I did the pull it felt a little weak in higher boost range. And when I let out it misfires hard until I free rev in neutral then it's fine unless I try and boost again.

What I've tried
New wires/plugs
Vcm logs look okay.
coils are all firing at idle

What I'm questioning.
At 10psi it reads 135kpa
At idle it reads 70kpa
Does that seem correct? Or do I have a bad out of the box map sensor. Linear and offset where provided by efisource.

Any suggestions? Tia
​​​​​
​​​​​​
​​​
70kPa does not sound right at idle unless it has a massive cam. Your boost kPa doesn't look right either since 100kPa is atmosphere, so you're only making about 5psi according to the computer/map, but your gauge shows 10 psi.
Reply
Old May 16, 2018 | 02:01 PM
  #3  
bbowerman's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2012
Posts: 111
Likes: 0
From: tulsa, ok
Default

That's what I was thinking. The cam is a .585/.585 cam. The numbers didn't add up to me. 35kpa doesn't equal 10 psi but my gauge reads 10 psi. The fueling is fine but I may have it scaled around that issue. And if I don't hit boost this truck is really smooth. I can upload a log and the tune file when I get home if that would help.
Reply
Old May 16, 2018 | 02:07 PM
  #4  
ddnspider's Avatar
10 Second Club
20 Year Member
Liked
Loved
Community Favorite
iTrader: (26)
 
Joined: Aug 2004
Posts: 14,628
Likes: 1,778
From: FL
Default

I would look to see if you're hitting some kind of cut out or something. Posting a log/tune would help.
Reply
Old May 16, 2018 | 02:12 PM
  #5  
bbowerman's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2012
Posts: 111
Likes: 0
From: tulsa, ok
Default

I attached a log and a tune. This tune RAF was off but I have since redone it. Everything else is almost identical.
Attached Files
File Type: hpl
road log 5-14-18.hpl (331.7 KB, 48 views)
File Type: hpt
newest rescale of ve OL.hpt (270.8 KB, 51 views)
Reply
Old May 16, 2018 | 03:17 PM
  #6  
soloman369's Avatar
9 Second Club
15 Year Member
iTrader: (13)
 
Joined: Nov 2006
Posts: 544
Likes: 12
From: League city, Tx
Default

For 1 your high and low octane tables don't match, 2 your shift tables for the trans are all wack. PE tps is way too high and you have PE delay on 2k as well. Spark seems to be really low in your cruising area as well.
Reply
Old May 16, 2018 | 03:25 PM
  #7  
bbowerman's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2012
Posts: 111
Likes: 0
From: tulsa, ok
Default

High and low octane maps are the same now. that was the last tune I had although my new one is almost the same. And trans tables are null it has an aftermarket controller that does that.
Reply
Old May 16, 2018 | 03:26 PM
  #8  
Fuhnortoner's Avatar
Launching!
5 Year Member
 
Joined: Apr 2017
Posts: 276
Likes: 5
From: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Default

70kPa at Idle? So youre boosting at idle?

If you meant -70kPa you have a vacuum leak.

If you truly meant 70kPa, your MAP sensor is probably fucked, or the calibration for it is fucked. If youre MAP says youre boosting 130 and your boost gauge says 10psi, youre probably dumping too much fuel, which explains the power loss and backfiring.
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

 Pouria Savadkouei
story-1

Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

 Verdad Gallardo
story-2

7 Most Reliable High-Performance Engines GM Has Ever Built

 Verdad Gallardo
story-3

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-4

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-5

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-6

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-7

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-8

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-9

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
Old May 16, 2018 | 03:27 PM
  #9  
bbowerman's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2012
Posts: 111
Likes: 0
From: tulsa, ok
Default

Yea man it's odd it says 70kpa at idle has ever since the new map sensor with vendor supplied values. Has me scratching my head. I have a good 2 bar map I may try just to see what it shows.
Reply
Old May 16, 2018 | 03:29 PM
  #10  
Fuhnortoner's Avatar
Launching!
5 Year Member
 
Joined: Apr 2017
Posts: 276
Likes: 5
From: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Default

Originally Posted by bbowerman
Yea man it's odd it says 70kpa at idle has ever since the new map sensor with vendor supplied values. Has me scratching my head. I have a good 2 bar map I may try just to see what it shows.
You probably need to change the calibration within the PCM for the 3 bar.
Reply
Old May 16, 2018 | 03:30 PM
  #11  
bbowerman's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2012
Posts: 111
Likes: 0
From: tulsa, ok
Default

Originally Posted by Fuhnortoner
You probably need to change the calibration within the PCM for the 3 bar.
Linear and offset? They are from the supplier.
Sorry I'm fairly new at this and learning as I go.
Reply
Old May 16, 2018 | 03:32 PM
  #12  
Fuhnortoner's Avatar
Launching!
5 Year Member
 
Joined: Apr 2017
Posts: 276
Likes: 5
From: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Default

Originally Posted by bbowerman
Linear and offset? They are from the supplier.
Sorry I'm fairly new at this and learning as I go.
I have zero experience messing with GM PCMs. Ive only messed with haltech. sorry man.
Reply
Old May 16, 2018 | 03:37 PM
  #13  
Fuhnortoner's Avatar
Launching!
5 Year Member
 
Joined: Apr 2017
Posts: 276
Likes: 5
From: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Default

https://www.google.com/search?rlz=1C....0.ZiABEzjIELY
Reply
Old May 16, 2018 | 03:40 PM
  #14  
bbowerman's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2012
Posts: 111
Likes: 0
From: tulsa, ok
Default

He is speaking of the linear and offset value which I got from the manufacturer. But it's a good read nonetheless. I believe those are all hptuners uses, but it is very possible I'm wrong.
Reply
Old May 16, 2018 | 03:46 PM
  #15  
bbowerman's Avatar
Thread Starter
On The Tree
 
Joined: Jul 2012
Posts: 111
Likes: 0
From: tulsa, ok
Default

I did see them talking of a maf pid I could have missed. May look into that when I'm off work.

Last edited by bbowerman; May 16, 2018 at 04:10 PM.
Reply
Old May 16, 2018 | 05:03 PM
  #16  
ddnspider's Avatar
10 Second Club
20 Year Member
Liked
Loved
Community Favorite
iTrader: (26)
 
Joined: Aug 2004
Posts: 14,628
Likes: 1,778
From: FL
Default

MAF is set to fail at 0hz so it's SD tune only. I assembly this bypasses your rpm threshold for airflow cause above 2400rpms it's set to read MAF only. None of the other spark or trans comments explain why it's fine at cruise and misfires at WOT. And 70kpa is vacuum, not boost. 100kpa is normally NA WOT. You could have a bum sensor or and offset and linearity issue as stated.
Reply
Old May 16, 2018 | 05:39 PM
  #17  
Fuhnortoner's Avatar
Launching!
5 Year Member
 
Joined: Apr 2017
Posts: 276
Likes: 5
From: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Default

Originally Posted by ddnspider
MAF is set to fail at 0hz so it's SD tune only. I assembly this bypasses your rpm threshold for airflow cause above 2400rpms it's set to read MAF only. None of the other spark or trans comments explain why it's fine at cruise and misfires at WOT. And 70kpa is vacuum, not boost. 100kpa is normally NA WOT. You could have a bum sensor or and offset and linearity issue as stated.
Im confused. Do you subtract atmospheric pressure or something?

Reply
Old May 16, 2018 | 05:42 PM
  #18  
G Atsma's Avatar
TECH Senior Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2016
Posts: 22,299
Likes: 3,619
From: Central Cal.
Default

Atmospheric is also known as 15 PSI.
Reply
Old May 16, 2018 | 05:43 PM
  #19  
Fuhnortoner's Avatar
Launching!
5 Year Member
 
Joined: Apr 2017
Posts: 276
Likes: 5
From: █▬█ █▄█ █▬█ █▄██▬█ █▄█ █▬█ █▄█
Default

Originally Posted by G Atsma
Atmospheric is also known as 15 PSI.
Depends on your altitude....
Reply
Old May 16, 2018 | 05:46 PM
  #20  
G Atsma's Avatar
TECH Senior Member
5 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2016
Posts: 22,299
Likes: 3,619
From: Central Cal.
Default

Sorry. I forgot to say at sea level. My bad...
Reply



All times are GMT -5. The time now is 08:45 PM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE