pinemind

Hi all,

Cross posting from another forum to get some additional eyes on this. I'm having a strange issue where my CSI circuit gear is all functioning properly (time switch is new OEM, verified CSI sprays fuel on cold starts, AFM/TPS/IACV/CSI Ohm out per FSM specifications), yet after sitting overnight, I get a delayed start when the CSI is plugged in. Temperatures when I try this are around 70 degrees and the truck has been sitting for 8 to 10 hours so completely cooled down. When I unplug the CSI electrical connector and start it, it starts instantly with no hesitation. I'm struggling to understand what could be causing it to start better without the aid of the CSI fuel and I'm looking for suggestions. Someone suggested there could be another source of excess fuel but when I say it starts instantly, it's the flick of a wrist and it starts (maybe 1/8th of a second). There's not really enough time for the main injectors to leak in too much fuel to cause a flooding condition when the CSI sprays its fuel, and the injectors are freshly rebuilt as well. Is it possible the CSI is slowly leaking fuel overnight thus the vapors are there enough to not need the extra fuel triggered by the cold start switch? I would think if I'm dropping that much fuel in over an 8+ hour period, it still woudln't start as instantaneously as it does since the pressure in the system would be lost with a leak after an hour or so.

Things I haven't replaced:
- Fuel pressure regulator
- Fuel pressure damper
- Fuel pump
- Cold start injector

I haven't been able to find any answers to this, since most problems are that the CSI system is not working and that is causing hard cold starts. In my case, the purpose of the CSI system is detrimental to starting even though it's functioning properly and providing fuel.

Any thoughts here on what I could check outside of the CSI leaking?