[radz28]

I'm not sure how much help this will be, but that's all I'm trying to offer. The actual/measured fuel pressure stays at 70-psi the whole time the car is bucking (if I understand what you're describing)? Is there TMA or throttle issues? Is the PI coming in around this time? What's commanded EQ?

I have a Katech in-tank twin pump bucket. Katech uses DW400s (a venturi and standard), at least that's what I have. So - maybe this will be helpful. Maybe not. I'm no tooner.

So far, I don't see any codes with the primary pump and mostly OEM settings. The aux' pump is coming in and seems to be reacting to what I'm commanding the REFLEX to do, so that seems like it's tracking fine (and I really like how I can ramp the REFLEX to come in smooth). I'm still trying to figure out how to get the primary pump output to match the requested fuel pressure though. At idle, it matches pretty darn close - enough such that I don't feel the need to worry. However - as soon as HOT or HIGH PRESSURE fuel modes kick-in, the pump doesn't change with the request with consistency or certainty.

By watching the INSTANTANEOUS FUEL FLOW in the SCANNER, I've been tinkering around in the BASE DUTY CYCLE table, and raising it in the areas it seems like pressure isn't responding as I am commanding. I'm also looking at voltage and the MINIMUM DUTY CYCLE table and trying to see if bringing-up the minimum pressure will help. I'm increasing the values in these places to see if I get any improvement. So - I have a little ways to go, and maybe I'm wrong, but I'll find out.

I wish I could be more helpful. There are definitely more knowledgeable people here by magnitudes greater than I could express. I'm just trying to pay back what I've gotten through experiences I've had so far. I still have lots' to learn.