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AFM744 AFM744 is offline
Cynical Misanthrope
 
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Join Date: Dec 2001
Location: Campbell, CA
Posts: 382
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So I ripped out the WUR, uuuh-gain. Since I only know about the more common 930 WUR by your pictures and descriptions I'm speculating that the entire lower section of my WUR is differn't. Below my manifold pressure diaphram is a second big chamber, and a pushpin that goes to a coil spring on the bottom. This spring is acted on by a 2nd heated bimetal. However, at room temp this spring is not depressed by the bimetal. I was reassembling this and contemplating disabling the lower section when the heating ceramic crumbled... :-/ OK, no more contemplating. Second observation, the upper bimetal has a two-stage heater with it's own tiny bimetal switch. When it's really cold the switch is open and only heats half the element, thereby maintaining lower control pressure longer in severe cold.

So, if my control pressure is not rising with warmup, either by heating element (within 120sec) or by conduction (after 30min), then the bimetals aren't acting on the springs. According to the Bosch CIS manual, the bimetals compress the springs when cold (lowering control press) but lift completely away from the springs at operating temp... so my WUR should be giving me 3.5-4b even if I take out the bimetals, right?

Thanks for reading my thoughts.
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Last edited by AFM744; 06-18-2008 at 09:54 AM..
Old 06-18-2008, 08:45 AM
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