My son's 91 Sovereign is more responsive than my 97VDP. At full pedal down the throttle is only about 80% open. The cable adjuster is at its limit. My garage suggested the cruise control could be involved as the cable passes through it, but that works perfectly.It's as if the pedal is limited in some way i.e. it's not going far enough to give full travel at the throttle. The kickdown works - just.
Any suggestions? Alan Lea

97 VDP X-300
88 XJ-s Hess & Eisenhardt
66 3.8 Mk2

Submitted by dougdwyer1@com… on Sat, 10/15/2011 - 21:28

Steven, thanks for the updated and clarified info.

[hitting forehead with hand] I thought the "between throttle quadrants" referred to the quadrants in the traction control unit, not the quadrants at the throttle body. Now it all makes sense :-)

However.......

With my newly acquired understanding I adjusted the cable as per the directions (very easy once you understand 'em) but didn't fare too well. The result was a full 1" free play at the throttle pedal and "Trac" and "ABS" lights staring at me.

So...I'm still thinking there's a "stretch" issue at play here.

I wnet back to the "just take up the slack" method and the excess play at the pedal was gone and the warning lights went out after a couple short drive cycles.

Cheers and thanks
DD

Submitted by stevejag@sbcgl… on Fri, 10/14/2011 - 15:23

Well, now that my online storage place is up and running again......

Per your requests, I have added some notes to the earlier document that I hope answers your questions. I like the Tracs system on the X300, but the cable setup does give a little heartburn now and then.

Hope that helps some.

Cheers,

Submitted by SE98-32482CJ on Fri, 10/14/2011 - 07:54

Well Doug you are not the only one--I asked the excellent techs at my dealer and they said "just take up the slack"! I will be interested in Steve's response too.

Submitted by dougdwyer1@com… on Fri, 10/14/2011 - 00:38

Steve, I'm glad you posted the adjustment procedure. Perhaps you can help me understand it. This step, specifically:

"Unscrew the throttle cable adjuster until there is 0.25 mm (0.010 in) clearance between the
throttle quadrants with the throttle resting on its closed stop."

I don't get the "between the throttle quadrants" part.

I've been adjusting my cables by simply taking up the slack...which seems to work well but the slack always return. I'd like to try the official adjustment method.

Thanks
DD

Submitted by stevejag@sbcgl… on Thu, 10/13/2011 - 00:29

Edited on 2014-06-02 23:39:32

I think what you are calling the cruise control is really the traction control actuator on your Vanden Plas; if it is located by the RH bonnet latch. Below is a link to download a paper describing how to adjust the two throttle cables correctly. It will amaze you how much better the car drives once it is adjusted properly!

Cheers,

Submitted by dougdwyer1@com… on Tue, 10/11/2011 - 20:36

I don't have an answer, but.....

I've had to adjust the throttle cables on mine 3-4 times in the last couple years. I really should investigate but the cure is likely to be more laborious than the simple adjustments.

Anyhow....

I wonder if the cables, your and mine, are stretching?

Just a guess...or should I say "a stretch" ?

Hopefully others will chime in.

Cheers
DD