DutyCycle Drops Problem!!

[Muhsen]

Hello everyone, i have an iron 6.0 Block with 6.2 heads, with 2001 PCM sierra 1500 (P01), 36lb Injectors the part number is (12594512), with Walbro 450lph and fuel regulator pressure (return fuel system)
so the problem is that i tuned my car in my town garage, and when the car is on WOT the duty cycle drops, it drops only when the car is on load, the garage said its a problem with fuel pump i changed it 3 times, Fuel injectors are good, sparks, wire , ignition coil everything is good, i tried something I took my friend's computer, put it in my car, and tested the car in the load and there is no problem, i tried to get into VCM Editor to see the details of my friends compuer, but its locked by another Tuner, so the problem 100% is from my Tune, there is a problem with the fuel tune! ( My tune is (Speed density) + i dont have O2 sensors on the Exhaust, i have only 1 sensor that is plugged with my AFR Aem gauge )

this is my Tune File and Data logs and i will put the data log for my friends computer

[5FDP]

Get your IAT working. You must have that sensor working for proper fuel calculations. That's probably why your VE doesn't look that good.

Your voltage is also dropping to 12.8- 12.9 under heavy load.

Fix those things and see if it gets better.

[Muhsen]

but when i plugged my friends PCM, there is no problem with the car and the duty cycle never drops under heavy load so i think i have no problem with the voltage

[kevin87turbot]

There are several problems with your vehicle and tune.

The IAT sensor needs to be fixed for proper SD fuel calculations.
The TPS is set way too high...1.08Volts. The max position for an idle is 0.82V. To fix this, you'll have to lower the TPS voltage to 0.82V, then, if needed, you can open the hole in the throttle body just a bit.
The target idle speed is 1100 rpm, but the minimum air flow table is stock. You'll need to increase that considerably...by around 50% or so.
Are you still running a 4L60E? The calibration is still set for one. You still have all of your torque management in your transmission TM tables.
The VE table is really messy and needs to be sorted out.
Finally, the injector DC% isn't your WOT power problem. See the ignition timing value when the injector DC drops to 76%? It's down to 1 degree. Very likely TM.

You might consider paying for a base tune at least. There are several of us on this board that can help with that.

[Muhsen]

The problem is that I paid for Tune for my town garage (600$, and he says that is the problem from either fuel pump or injectors, i already change it and the problem still, i will try now to get the AIT sensor and low the TPS sensor and see what will come hope it work.

[Muhsen]

Are you still running a 4L60E?

The engine is GM 2001 6.0 iron block with 6.2 heads, on Nissan patrol safary Body and gear.

[kevin87turbot]

The engine is GM 2001 6.0 iron block with 6.2 heads, on Nissan patrol safary Body and gear.

Which transmission are you running? Is it the GM automatic 4L60E transmission, or the Nissan manual transmission?

[Muhsen]

Which transmission are you running? Is it the GM automatic 4L60E transmission, or the Nissan manual transmission?

The nissan manual transmission

[kevin87turbot]

There are several things in your tune that is causing your performance issues.
It has a lot of transmission codes that need to be removed for your application.
The previous issues that I mentioned also need to be resolved.

PM me if you'd like me to straighten them out for you.

[Muhsen]

After decreasing the TPS voltage to 0.92, and close the hole in throttle body little bit, then i edti my idle rpm (Base Setpoint) from 1100 to 850, then idle airflow (Base running Airflow) I increased the numbers by 30%, and that's all everything worked perfectly.

This is my tune file after Aiflow edit and my log files


idle airflow editing.hpt

no problem after decrease rpm and throttle sensor and airflow rpm.hpl

no problem at all.hpl