Long story short, helping a guy swap a D24TIC into an 83 LT28, got it in and running, and I have an issue I haven't run into before.
Teast ran the motor before install, and it leaked out the pump input, so I put a new seal in.
We've had some issue with air suction upstream of the fuel filter, and blew a couple IC hoses off, so we were driving around with the engine cover off , watching stuff happen.
Over 4000 RPM or so, it starts to pull air.
Turning on the 4PSI electric lift pump stops the bubbles, but 3-5 seconds later fuel will leak out the input and sling off the pulley.
Lower speed, or not running the lift pump, it stops leaking.
Removing the lift pump, we still get air from something in the filtration setup.
I'm confident of fixing the air going through the filter, they are new, there are 2, with a kind of inordinate number of lines/clamps ,etc.
Why does the new seal only leak at speed?
Anyway, here is what a D24TIC looks like in an LT