2000 gmc sierra with 6.0, sloppy stage1 cam & valve springs, ported 799 heads, stock manifolds, stock intake, cold air intake. It starts perfect cold, has a long crank after its warm and have too press foot pedal half way down to get it too start, idles perfectly and no hanging idle when driving, fuel trims are within 0 to 1. Tuned ve and maf with wideband, replaced injectors with marine 8.1, because stock 24.5 maxed out duty cycle, didn't have injector data just changed flow rate. I have added air too base running airflow but still long crank hard start when warm. Am I missing something in the tune or do I need good injectors with data too get this too start correctly. As an afterthought it only does the hot start after it sits for half an hour, it will start just fine once you shut it off n hit the key again, it almost acts like old school carb vapor lock.

 

If you press the pedal halfway and it starts ok, you may need to reduce the cranking fuel and increase startup spark.. And, yeah, you need all of the injector data so you won't have to try and patch up the rest of the tune for the injectors.