I tried to get her running again today. Using the clear line to see what was going on I first tried to get her to crank using my electric lift pump. I learned that the pump is worn/old/clogged and not pumping anymore.
So next I tried removing the electric pump and just hook up my fuel supply directly to the IP. I used my hand vacuum pump to pull fuel from the tank
to the pump (also seeing if I had a clog in the tank
/lines) and I got some fuel up. Then I cranked her with the injector lines cracked at the injectors. I noticed that there was an air bubble in my supply line and it wasn't going away. I figured, eh, reconnected the injectors, and tried again. I believe that the internal lift pump does work as I saw fuel being lifted and flowing, I also earlier noticed that fuel was splashing from the injector lines (but not very much.)
Determined to try to get that air bubble out of my supply side at this point, I used my hand pump again at the return side and started pumping. I was getting fuel to flow into my collector but that air bubble was going NOWHERE. I then disconnected power to the fuel disconnect switch, removed the vacuum pump (which still held 22 in/hg) and I saw bubbles coming back up the fuel supply line!
Question here, if the disconnect isn't energized, shouldn't the fuel return being disconnected NOT allow air to go back to the supply line, or does it only cut fuel from going to the injector rails?
If that air bubble refuses to go inside the pump, wouldn't that indicate a weak internal lift pump?
With the injector lines cracked, shouldn't I see large splashes of fuel or little piddle splashes? (I'm talking a very little amount here, an empty spray bottle with a very small amount of liquid/mostly air in the tube sized splash.)
One more thing, when I was pumping with the hand pump, I saw a lot of little bubbles in the pump line. I figured some of it was due to the loose connection that the vacuum pump had on the return line (it was only a slip on connection, I didn't clamp it or make it secure.) I will try tomorrow using clamped hose nice and air tight to see if it goes away or if it's the same.
Will too much air in the IP make the lift pump seem weaker?