Quote:
Originally Posted by jvictormp
I've installed an adittional presssure sensor connected to a pressure display in the cabin. It's good to see how the pressure behaves, and its nuances, like:- When you prime the pump, pressure goes to max (90~92 psi), then drops to 86~87 when pump stops, and keeps dropping in a fast rate (after 20 seconds, it's like 70 psi and going).
- You prime again, and it holds better, 20 seconds it's on 80 psi.
- When engine is hot, prime pressure is kept even better. 84 psi after 20 sec.
Can't say why the difference, but I have a clue about the cause of the drop: there should be a check valve in the pump discharge, and that valve may not have the original tightness, letting some fuel to flow back to tank.
- You can see that, during engine idle, pressure is kept in 42~45 psi. Sometimes you push pedal hard, and pressure goes to 95 psi. Sometimes you don't push hard, but revs to like 4000 rpm, and pressure goes to 75 psi. It keeps oscilating like that as you vary engine speed and load.
In the pictures you can see the original pressure sensor in series with the additional pressure sensor.
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Absolutely brilliant! Thanks for sharing your setup and observations. I hope you'll never need it, but given the slow pressure leak down behavior when normal, a wide open failed injector would be immediately noticed with a stopped engine as I'm guessing pressure would to fall to zero within seconds.