Photo lower small Line found it disconnected and cannot see where it attaches. Been getting both banks lean DTICs.

 

There are usually two lines from that vacuum access point on the throttle body. That one goes to the fuel pressure sensor, #1 in the attached. Those lines are as fragile as tissue paper (really bad design), and someone has replaced a broken line with rubber vacuum hose. The open end of the hose should have an l-shaped connector on it, likely with a bit of the original vacuum line on it. It's probably plugged into the fuel pressure senor, located on the front end of the US passenger side fuel rail. Common to replace the crappy plastic with rubber vacuum line. ALSO: the fuel pressure sensor vacuum connector on the switch is very fragile and can break off if you twist or bend it. Good news is it can usually be reglued with epoxy. In any case, be gentle around these crappy vacuum lines. I usually don't have much heartburn with Jag designs, but this one is uniquely bad.

Yous should carefully check the entire assembly of that vacuum line for breaks. The other end goes to the secondary air injection valve, #18, on the front of the engine. It can also be open, leaking or broken.

While this will likely make a huge difference in your LTFT, there's a lot of vacuum leaks in these engines as they age. Correct LTFT is 0. The code you mention is set at 20%, which is a big leak. While it's always correct to get 0, up to 5% variance is easily compensated by the fuel/air map. Bit of an art form on these to get LTFT to 0. Search "smoke test" on this forum for how to be an artist.

 

thx , looked all over the manuals for a vacuum routing diagram with no luck.

 

Heres why I couldnt find a place for that hose to go. Nipple is snapped off. Great, I get to order another part.

 

J/B Weld, if you still have the stub...?? Being careful to not get any in the opening. Nothing to lose...

 

JB Weld or if you have a drill bit handy...

 

Probably a inexpensive part. My 4.2l has a FOMOCO branded FP sensor. Appears this can be sourced from many different Ford parts or purchased on E-Bay. This was discovered by accident when I was looking and found a Ford FP sensor on E-Bay used for $5 incl S&H. Nothing wrong with my OEM Jaguar unit but with it labeled FOMOCO,, I gave the other unit a try. Still using the identical E-Bay unit and all is well.

 

Probably, but I like to make broken parts functionable, just for my own satisfaction.

 

Mine broke of when I was fixing the vacuum line. Epoxy has done the job for the last two years. Make sure you have the L-connector from the crappy little vacuum line, or it will have nothing to attach to, even if you fix or replace the FP sensor. The L connector looks similar to the one on the TB, only with one port instead of two. I bought a new vacuum V-line, I think for $50 or so. Make sure you get the right one; some have the three ports you'd expect on the V, some have another port.

 

thanx for the feed back. I went ahead and ordered a new one, Its interesting that the sensor is not getting vacuum but no DTICs are set. Plugging the vacuum for now also fixed the check engine light and no DTICs for that.

Any thoughts on what the sensor does ?

 

I had the sensor book around here but can't dig it up. I can only assume the vacuum connection helps adjust the fuel pressure (or maybe the injector pulse timing) to allow for the true total pressure differential between the fuel pump and the engine vacuum to meter the correct amount of fuel. That said, there's a direct sensor reading of engine vacuum, so maybe it has some other use. Guessing.