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IDI Engine / Re: Need help with tracking down air leak in 1.9 AAZ pump
« Last post by Buji88 on Today at 10:21:47 am »There are only a couple spots that will allow air to be pulled in.
The banjo at the front of the pump, the mainshaft seal,
and the pressure regulator that you changed the seal on just before all this problem started.
The pressure regulator compares the pressure inside the pump to pressure of the fuel coming into the pump.
Through a passageway that goes to a spot behind the mainshaft seal,
which continues on to the pump input, near the banjo bolt.
If it is pulling in air at the pressure regulator, you could probably pour/spray some diesel on it and see if it gets sucked in.
Or maybe spread some vasoline on it, see if it gets pulled in or anything changes.
I think you would have to mess up both of those o-rings to get it to pull in air at the pressure regulator.
I changed the main shaft seal when I was initially having issues and it fixed it then. Im curious about the cold start lever cover because it was also leaking, I changed it, then it failed, so I wonder if its where its getting sucked in as well. I have a block off plate from a pump in my parts piles and since Im not using the cold start for my swap I wonder if that will it.
That is a great suggestion, Im borriwng your idea and Im going to block off the fuel inlet, injector return and put my vacuum tester to the outlet and see if I can bet it build some vacuum and hold it. Probably spritz some diesel on the areas that have seals and see if it gets sucked in.
I couldn't find the exact size of o-rings for the regulator so I just ended putting the ones I took out back in. We will see how it goes I guess. I also did pull a random piece of red plastic film out from the pressure regulator, I wonder if that was part of something inside?