5.3 Gen 3 Need help with tune
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Teching In
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5.3 Gen 3 Need help with tune Hello everyone. My name is Egor.
I am building a Van G10 with a swapped 5.3 LM7 engine.
Now I ask for your help with turning, as I have no experience.
Setup:
Gen 3, LM7 5.3 / 4L60E
Camshaft: Summit racing Truck Stage 2
Springs: LS6 (blue)
Centrifugal supercharger Powerdyne 9
MAP 3bar, IAT (in intake namifold)
SD 3 bar.
Problems:
1. After slight acceleration on idle, RPM coming to 2000-2400 and stay for few seconds after come back to idle.
2. In drive, only very steady acceleration, If push rapid no acceleration at all.
3. PCM doesn't see Manifold pressure more than 105 kPa. But MAP sensor from LS9 3 bar ( 12592525 )installed.
My present tune file and log in attachment.
I appreciate any help. Thank you in advance.
I am building a Van G10 with a swapped 5.3 LM7 engine.
Now I ask for your help with turning, as I have no experience.
Setup:
Gen 3, LM7 5.3 / 4L60E
Camshaft: Summit racing Truck Stage 2
Springs: LS6 (blue)
Centrifugal supercharger Powerdyne 9
MAP 3bar, IAT (in intake namifold)
SD 3 bar.
Problems:
1. After slight acceleration on idle, RPM coming to 2000-2400 and stay for few seconds after come back to idle.
2. In drive, only very steady acceleration, If push rapid no acceleration at all.
3. PCM doesn't see Manifold pressure more than 105 kPa. But MAP sensor from LS9 3 bar ( 12592525 )installed.
My present tune file and log in attachment.
I appreciate any help. Thank you in advance.
The log only shows 1 bar readings because you have selected MAP sensor SAE in the channel list. That is the default that the software asks if you want to use, but you have to select the 3bar sensor for your scanned channel. Ignore the prompt to pick SAE and click on "I know what I am doing" when prompted by the software. The rest is a matter of tuning based on the data you get when logging.
Thread Starter
Teching In
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Injectors Stock. You right, it will be done. but now my problem not a shortage of injectors. I still cant reach the limit of stock injectors, due to problems with acceleration.
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Under your DTC's---P0101,102,103, all should be Mil on First error to get to SD.
Your Base running airflow is high---go back to stock setting. Add as needed for the cam.
Look at your Primary VE table in 3D view---it is waaaaay too choppy down low. Go back to the stock setting and start over.
Your fuel tables are set up for a boost referenced fuel system. Is that what you have?
Turn on yiour Short term fuel trims and tune with those while you are under 4000 rpm and doing drive around---non WOT tuning. Use the wideband for WOT tuning.
Your Base running airflow is high---go back to stock setting. Add as needed for the cam.
Look at your Primary VE table in 3D view---it is waaaaay too choppy down low. Go back to the stock setting and start over.
Your fuel tables are set up for a boost referenced fuel system. Is that what you have?
Turn on yiour Short term fuel trims and tune with those while you are under 4000 rpm and doing drive around---non WOT tuning. Use the wideband for WOT tuning.
Last edited by dw456post; Jul 7, 2025 at 02:49 PM.
Thread Starter
Teching In
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Thanks to all who replied.
I have made several modifications in the past few days
1. Replaced the idle speed control valve
2. Replaced the throttle position sensor
3. Installed the TBSS manifold
4. New mechanical throttle 92 mm
5. Injectors 54 lb/hr (12609749)
6, fuel pump 320 ltr/hr
7. Fuel regulator.
For correct Injectors data I downloaded 2009 H2 with same injectors. Could you please advise what parameters I should copy from this file?
I updated only FLOW RATE VS KPA
I have made several modifications in the past few days
1. Replaced the idle speed control valve
2. Replaced the throttle position sensor
3. Installed the TBSS manifold
4. New mechanical throttle 92 mm
5. Injectors 54 lb/hr (12609749)
6, fuel pump 320 ltr/hr
7. Fuel regulator.
For correct Injectors data I downloaded 2009 H2 with same injectors. Could you please advise what parameters I should copy from this file?
I updated only FLOW RATE VS KPA
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Flow Rate vs KPA
Min Inj Pulse
Offset vs Volts vs VAC
Short Pulse Limit
Short Pulse Adder
Important question: Do you have a return style regulator that is boost referenced. If you do, Flow Rate and Offset vs Volts vs VAC should be set up different.
Min Inj Pulse
Offset vs Volts vs VAC
Short Pulse Limit
Short Pulse Adder
Important question: Do you have a return style regulator that is boost referenced. If you do, Flow Rate and Offset vs Volts vs VAC should be set up different.
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Teching In
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The van runs well on cruise and idle, but when accelerating hard the engine does not respond, there is a big delay and a drop in ignition even when doing it at idle.
I attached my latest tune, maybe you can help me find the cause
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Here is the data needed for your injectors. I pulled it off the HPTuners website. This data is for a non return dead head fuel system. You haven't stated what you have.
You haven't changed P0101,102,103 DTC's to Fail on First error. Required for switching to SD
Copy the High Octane Spark table to the Low octane table. It runs on Low when you changed OS.
Did you turn on the STFT's to tune with?
You picked a hard setup to start tuning. You can easily blow up that engine with a small mistake. Don't do any WOT until you get the lower rpm areas tuned and then ease into the higher rpm's. Don't just floor it and expect it to live. You have to extend your primary airflow table to cover the higher KPA (pressure) numbers.
You haven't changed P0101,102,103 DTC's to Fail on First error. Required for switching to SD
Copy the High Octane Spark table to the Low octane table. It runs on Low when you changed OS.
Did you turn on the STFT's to tune with?
You picked a hard setup to start tuning. You can easily blow up that engine with a small mistake. Don't do any WOT until you get the lower rpm areas tuned and then ease into the higher rpm's. Don't just floor it and expect it to live. You have to extend your primary airflow table to cover the higher KPA (pressure) numbers.
Thread Starter
Teching In
Joined: Jul 2025
Posts: 5
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Here is the data needed for your injectors. I pulled it off the HPTuners website. This data is for a non return dead head fuel system. You haven't stated what you have.
You haven't changed P0101,102,103 DTC's to Fail on First error. Required for switching to SD
Copy the High Octane Spark table to the Low octane table. It runs on Low when you changed OS.
Did you turn on the STFT's to tune with?
You picked a hard setup to start tuning. You can easily blow up that engine with a small mistake. Don't do any WOT until you get the lower rpm areas tuned and then ease into the higher rpm's. Don't just floor it and expect it to live. You have to extend your primary airflow table to cover the higher KPA (pressure) numbers.
You haven't changed P0101,102,103 DTC's to Fail on First error. Required for switching to SD
Copy the High Octane Spark table to the Low octane table. It runs on Low when you changed OS.
Did you turn on the STFT's to tune with?
You picked a hard setup to start tuning. You can easily blow up that engine with a small mistake. Don't do any WOT until you get the lower rpm areas tuned and then ease into the higher rpm's. Don't just floor it and expect it to live. You have to extend your primary airflow table to cover the higher KPA (pressure) numbers.
I will folow to you recommendations and revert with the results soon.
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If you have the HPTuners program, you can find the info on the HPTuners bulletin board. There is a search box in the upper right hand corner to search for items. The guy that posted that info should be the name on the file that I sent to you. You can also post your file and info on there and get help with tuning. There are a lot of good tuners on there. There are some guys that will be hard on you, but that's just part of getting help. Don't be discouraged.