Purpose of shut off valve in CIS return line?
11-07-2006, 05:01 PM
#1
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Purpose of shut off valve in CIS return line?
Anyone know the purpose of the shut off valve in the CIS return line @ the passenger side rear wheel well under the compensating tank? Shut off valve is item 18 illustration 201 in PET.
The reason I ask is that when I loosened the banjo bolt on the return line @ the fuel distributor there was a large air lock(I could hear air hissing from the connection ). I thought is was odd that pressure was checked on that side of the distributor. I would have thought it would be free flow back to tank from the distributor. The car has not been run for about two weeks.
The reason I ask is that when I loosened the banjo bolt on the return line @ the fuel distributor there was a large air lock(I could hear air hissing from the connection ). I thought is was odd that pressure was checked on that side of the distributor. I would have thought it would be free flow back to tank from the distributor. The car has not been run for about two weeks.
11-07-2006, 07:16 PM
#2
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The check valve #18 is for the tank AIR INLET . As fuel is consumed the tank needs to inhale but never exhale or the tank will collapse or fuel vapors would be vented to the air. So it has NOTHING to do with fuel or fuel pressure but allows air to enter the fuel tank..... The fuel return line goes to the top of the tank and flows back into the fuel level sending unit. The return line is Item 46 on 201-05
