944 Turbo ignition advance doesn't change
#91
Cycling valve has been tested so that it clicks when power is applied. The hose going to the turbo from the cycling valve has been blocked so the turbo should give full boost regardless so even if the cycling valve would be faulty it wouldn't cause a problem? Or can the valve leak from inside out?
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VAN has a great point, check that WG!! A Great Strategy is "WHO did WHAT Recently? 9 out of 10 times the problem is related to recent service or mods...
#92
You say the noise is by the throttle body.. and I hear air bypassing when you are building boost. The boost side of the bypass valve is by the throttle body.
Your original description was there was a POP and a loss of boost. It could have ruptured the diaphragm and although you can't blow through it, at the onset of boost with a couple hundred CFM trying to blow it open, it could be bypassing. It's hard to test them with shop air because of the volume.
I'd put a bypass valve in it.
Your original description was there was a POP and a loss of boost. It could have ruptured the diaphragm and although you can't blow through it, at the onset of boost with a couple hundred CFM trying to blow it open, it could be bypassing. It's hard to test them with shop air because of the volume.
I'd put a bypass valve in it.
#93
You can see the edge of the diaphragm can rupture but the valve can still stay sealed in vacuum or low boost because the center of the port is still closed by the spring pushing on the center of the seat.