[xj-s] Delanair Vacuum Solenoids

My Fellow Enthusiasts!

I went crazy with my Digi-camera yesterday and uploaded a number of pics to
the XJ-S General Photo Album. The one entitled “Delanair Vacuum Solenoids”
is the result of my chasing down some problems with the Climate Control
system. I was not getting air from the central vents and also noticed a
pronounced “KER-THUNK” from the upper flap doors when decelerating from
45-50 + mph to a stop. I was prepared to disassemble the entire dash until
I talked to my local Independent Jag shop, and he informed me that this was
caused by a vacuum leak not letting an upper flap “get out of the way” of
the upper servo-controlled blending flap. Armed with this information, I set
about to access the vacuum solenoid packs, and sure enough, found a “dead”
one (open circuit) and swapped it out. I then followed up with my “Mity-Vac”
vacuum pump to check the integrity of the vacuum motors/actuators, lines,
valves etc. and discovered a pretty major leak, it turned out to be a crack
in the plastic “T” fitting that supplied the main vacuum to both solenoid
packs, if you trace the “feed” line as noted in my pics to an area on top
and centered on the trans tunnel, immediately behind the radio, you will
find it. I replaced it with a universal piece (about 1/8", 3mm) from
Autozone. Everything else checked out good, sure beats stripping out the

Anyway, I thought I would share this with everyone.

-Don Buresh, 1991 XJ-S V12 Coupe, Classic

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