Duramax Lifetime Supporter
Join Date: Aug 2012
Location: Carson City, NV Proud Participant, Federal Witness Protection Program
As I understand it the only way to measure injector return rate is by means of something called a “bottle test” in which return lines from each bank are disconnected and fuel flow is measured following a set cranking time. This test may also, and much more easily, be done just upstream from the fuel tank, although a measurement there reveals total return, not per bank. Still useful 411.
To kinda answer your question, a YouTube video I’ve watched of the measurement being done at the tank did not require special measures (no pun intended) to secure the fuel line, as would be expected if a high pressure flow was present, so I’m thinking return line pressure is just enough to push fuel back to the tank.
Anyone else want to weigh in?
2003 GMC Sierra 2500HD SLE ExtCab CA Emissions; 155k; Allison 1000 w/Transynd X2 Flush & Fill; 8' bed; AFE/CAI; MBRP 4" Exhaust; Side Tint, 33% VLT, rear, Limo; Smittybilt Stainless Side Nerf Bars; Sprayed-in Bed Liner; MadJack Fuel Filter Access Door; Regular Used Oil Analysis (latest available on request), Blackstone Labs; EGT/Boost Gauges; Dual Chrome Dipsticks, JC Whitney; Stainless Steel fuel filter head bleeder screw; New WP and Hydroboost; Billet Aluminum Fuel Filter Housing Spacer; Professionally repaired instrument cluster (new steppers and lamps); Does anybody ever read this s%#t?; Injectors under warranty @ 70k; 2nd set DIY @ 155k