Injector flow rate for deleted EVAP

New to tuning and am going through the tune on my TA because it is having a few issues. The car had a bad throttle body and the tuner was having a hell of a time getting it straight. Replaced the throttle body and decided I was going to teach myself tuning since I daily a G8 GT and am doing an 8.1L swap into my 95 Burb.

Anyway, my car is a 98 TA with a mild 6.0L LQ9 swapped in, Futral F13 112cl cam, all that good stuff. I have deleted the EVAP system and the car is now returnless. I was looking at the tune and it has a straight line for the flow rate. I read that a sloped flow rate is for returnless systems and a straight line is for returned systems, but not sure what it should be for my car as a converted one.

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Originally Posted by 98Birdman

New to tuning and am going through the tune on my TA because it is having a few issues. The car had a bad throttle body and the tuner was having a hell of a time getting it straight. Replaced the throttle body and decided I was going to teach myself tuning since I daily a G8 GT and am doing an 8.1L swap into my 95 Burb.

Anyway, my car is a 98 TA with a mild 6.0L LQ9 swapped in, Futral F13 112cl cam, all that good stuff. I have deleted the EVAP system and the car is now returnless. I was looking at the tune and it has a straight line for the flow rate. I read that a sloped flow rate is for returnless systems and a straight line is for returned systems, but not sure what it should be for my car as a converted one.

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It should be sloped. Increasing flow rate with higher vacuum.

its not if it's return or returnless its if it's for a referenced fuel reg or a non referenced fuel reg, if your fuel pressure is constant then u need a slope in IFR, if your pressure references vacuum/boost then the IFR is flat lined

Gotcha. Mine has the in-tank regulator, so it is non-referenced. I put the slope in the IFR.