99 XJ 258k 4.0 6 hole injectors and HKS throttle body only things I've changed on the engine. Cold just trying to start takes a full 4 seconds to start... But if I turn the key on and off then try starting it does its normal 1.5 second start. that's to long too I think but was consistent. I changed fuel regulator on top of the pump, put in a quality Bosch regulator...
Hoping somebody could give me a place to start?

 

If you already addressed the in-tank components, including the check valve, it sounds like the injectors are leaking down while it's sitting. Seems to be a common problem with the Chinese bosch knockoff injectors. Borrow a fuel pressure gauge to see if it's holding pressure after you turn the key off, Pinching the line to the tank would determine whether it was injectors or at the tank.

 

Nice, thanks.. When I did the leak down test I "assumed" the injectors weren't leaking because they were new... Suppose hoping would be a better word