Originally Posted by JamesM3M5
The flow sensor is brand new. I had a failure on a different car, swapped my known good one on, and waited for this new one as a replacement. It read dead zero or intermittently, not low. Mine reads, but very low. No clogs, no debris, no scum/muck/crud in the system, it's dead clean and working.
I haven't pulled the nozzles to observe flow/spray pattern, haven't had time, yet. But from what I can discern, the pump just seems weak when pumping against no resistance. Once I put my finger over the outlet hose, it definitely does not build pressure anywhere near 150psi.
Well, you need to do a process of elimination. If the kit was working fine before you did some maintenance on the setup, I'd go back to what you messed with.
IMO it's a clogged pump, but that's a completely blind assessment.