What all is needed to change in the tune for going to a return fuel system. Ive already flat lined the fuel pressure table and its helped some. And it seems is super rich when starting as there is a fuel smell along with black smoke. I've searched and couldn't quite find what i was looking for. Thanks in advance!

 

Offset table also. What injectors and what did you set the IFR table to? Sounds like you used the wrong values and its dumping fuel.

 

I pmd you. It has been rich since i went return.

 

2003 trucks came from the factory with a return style, vacuum referenced FPR, style fuel system. You can download a stock tune file from the HPT repository and compare the differences. Not that you can expect a simple copy and paste, but that would be a good starting place.

 

I bet you dont have the fuel pressure set right.

What are your injectors rated to flow at 4bar (or 3bar)? If you have your base pressure set to 58psi (4bar) then your injectors will be exactly their rating if they are rated at 4bar. Same with 43psi base and 3bar. If you run some other pressure you will need to scale the injectors by: rated_flow* (actual_pressure/rated_pressure)^0.5

To set the fuel pressure, with the engine off turn on the pumps and adjust regulator until its pressure is what you desire. If you set it with the engine on and the reference line hooked up it wont be right (unless you account for engine vacuum).

You can tweak the other stuff but this is the big one.

 

I had to redo some tables for going return. It does ok now. Just some other tweaking to do to get it where i want it.