I feared it was intake or supercharger gaskets, turned out to be a hose that popped off. No idea what this hose does (am curious if anyone knows) but it's attached to the SC outlet plenum on the driver's side just behind the aftercooler connection. It's tucked down a bit so long nose pliers were used to put it back on. The hose fit was pretty loose to I put a zip-tie on it, held the locking part of the tie with one pliers and used another to pull the tie tight. I used a special zip-tie that's designed for hoses (shaped to wrap around better) but a regular one should work too.

 

It's the manifold pressure reference line to the fuel pressure sensor.

Fuel pressure is referenced to manifold pressure.

The fuel pressure sensor is on the left side (LHD drivers side) fuel rail, near the firewall. On my XJR there are a couple of joints in that hose and I ended up putting cable ties on all the joints and the barbed fitting of the fuel pressure sensor too.

 

Thanks! I'm glad I didn't get on it while that hose was off, guessing the system might have compensated, but it would possibly induce a lean condition. The display read "limited performance"; I goosed it just enough to know that it wasn't in limp mode, but no further. I didn't notice any difference in drivability.

 

Just a comment. I recently found some pliers I had not used before. They are great for sneaking in and pulling a hose off a nipple or putting a hose on.

Called Compound Joint Hose Pliers.

GearWrench KDT 82107 3 PC Double x Hose Pliers Set | eBay

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