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IDI Engine / Re: Need help with tracking down air leak in 1.9 AAZ pump
« Last post by fatmobile on June 04, 2024, 11:57:43 pm »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.
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.