thanks for the picture. Can you expand it to show the whole wiring harness diagram?

 

You really need the S57 Wiring Guide.

PM me your email address and I'll send it to you

Cheers
DD

 

I've lost track of where we're going in this thread.

Xjeffs, are you having a bog/hesitation problem? if so, when does it occur?

If you have a hesitation on initial throttle application and/or light throttle application, I wouldn't be looking at these enrichment switches....although they should be returned to proper operation on general principle, obviously. I'd be looking at the TPS or other items mentioned early on in this thread.

Cheers
DD

 

Initial opening and Slow gradual increases in throttle are fine. The engine runs very smoothly. A quick blip of the throttle to about 20% open and it completely chokes. I have verified the TPS is set correctly at idle and over the whole range.

Sorry to hijack this thread. I'm not trying to solve my problems on this thread. Just trying to get some info but I appreciate the help.

 

Jeff
This is a classic symptom on the HE V12 engine of the ignition timing being far too far retarded.

 

That would make sense as my timing seems very retarded at idle and 28 degrees at 3000RPM in park both with the vacuum connected.

 

for sure... you guys and this site is amazing and a joy!

 

Grant, was there a pdf attached somewhere on how to adjust this?

 

X2... I second that, hands out, lol
I'll be digging around and trying to connect it up, tomorrah

 

Here ya go. Since you asked sooooo nicely.

 

Grant, was there a seat-of-the-pants before/after difference when you adjusted your switch?

Cheers
DD

 

Doug,

Not a seat of the pants result as such.

I had hesitation as I took off from a standing start, or sedate style acceleration in traffic. VERY mild, but I could feel the song was off.

I cannot get full throttle, never going to get that much movement in the leg/ankle as long as I take breathe.

I decided it was too lean.

Drove around for a few days with a vac gauge taped to the column cowl, and noted readings as I drove to and from.

Checked the on/off of that Blue/White switch. Found that my vac drops were rarely getting to the "closed" setting.

Looked at altering the capstan cam etc, too hard.

Dug out that Black stuff, and found the screw, turned the screw, as you do, and settled for what I wanted for MY driving ability.

It smoothed the beast significantly, and I would say a slight, noticeable, increase in "oomph" due to the fueling of course. I thought fuel usage would be horrible, not so, so that switch stayed where it was set.

NOW

A "normal" driver may find the factory setting is OK, but with today's traffic and reduced speed limits etc, in the suburbs, maybe a tickle will help any V12.

Also, mine had a 16CU, XJ40 throttle discs, cold air intakes, no vac "thingy" in the ECU vac line near the battery, NO AAV, Balance Pipe, Overrun valves, or other emissions stuff.

Timing was at, NO IDEA, I drive time then all, never looked at the plate with the engine at 3000rpm, I simple am not that brave/stupid.

 

Grant I've noticed you mention the leg / kickdown issue before...have you ever considered wiring up the kickdown switch to a trigger or paddle switch fitted inside the car? Say on the steering wheel or near the gear shift?

I suppose you can do so with the gear shift but the 3spd has a *** to prevent accidental downshift to 1st

 

NOPE.

Once I tickled the beast, AND removed that gearlever pin, AND, had a stick alongside the seat for when I really was in a hurry (rarely used), all things panned out performance wise with only about 2/3 throttle at best.

Sold the car, the getting in and out was just getting too hard and painful, and removing that sill hump was not an option.

The S Type (X200) has no sill as such, so in and out was simple. A LandCruiser desroyed that in the local carpark, so now I have a 2010 X Type 2.1V6 Front Wheel Drive, and its is just suited in so many ways. Hated them when they first came out, but by the end of run, they were sorted well. I doubt your market gets that "sweet" 2.1V6 and FWD, but we did. The AWD was less popular.

Looked at an X350, but it did not get the nod, too many $$ to keep, especially that silly suspension system.

XF is now on the radar, but this "bug" has removed soooooo many from the market, I will wait. I still got 30 years left in me, HA.

 

As usual, beautiful write up, Grant...
Here we go...
Wish me luck,,, bit is out O the bag...

 

Go on Grant - you know you wanna ... I got the XF SV8 and it has so far set so many benchmarks that numerous newer cars simply cannot reach, thought of selling but every time I do and look around nothing else gets close, then I drive it and the affair starts again. I didn't do the XFR simply because a fully specified XFR is pretty rare / non existent and I detest dark leather which 99% of the 2010/11 XFR's are - I prefer light coloured interiors.

The X250 is hands down my favourite daily so far, I regard it as one of the last Jaguars before Tata started turning it into just another plastic rep mobile - a Jaguar for the masses (the nerve of these people - a repmobile with a premium price tag)- I wouldn't have a new Jaguar gift wrapped.

Just beware - for DIY this car takes complex to whole new levels

 

take pictures of your work!

 

Greg you were right. with the advance adjustment fully advanced, I was still 8 degrees too retarded at idle and 3000 with no vacuum.
Popped the distributer cap and loosened the hold down screws, adjusted and set it correctly.
Runs great now, no hesitation or stumble.
​​​​

 

How did this turn out? Did you get it resolved?

 

Sorry to trail off but are you saying the trans (kickdown) is directly effected by braking and overrides to shift down presumeably to stop faster by gear + brakes?