Throttle pedal "stop"
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Senior Member
Joined: May 2010
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From: Ireland
Throttle pedal "stop"
Just poking about yesterday on my donor car and discovered that the throttle pedal "stop" is adjustable, in that it will screw in and out. So, I got to wondering, does that mean by screwing it in, you extend the travel on the accelerator pedal and so increase top speed?
Likewise, screwing it out will have the opposite effect. Or is there another stop mechanism somewhere on the engine? Not that I want to go faster, as the top motorway speed allowed here is 120kph.
Just wondering?
Likewise, screwing it out will have the opposite effect. Or is there another stop mechanism somewhere on the engine? Not that I want to go faster, as the top motorway speed allowed here is 120kph.
Just wondering?
Senior Member
Joined: Jun 2011
Posts: 307
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From: Cypress, TX
I can't provide a definitive answer, but I'll hazard a guess ... the adjustment is only for the pedal itself and not a "throttle adjustment".
Have someone mash the pedal and you observe / take measurements of throttle movement underhood; adjust pedal, repeat measurements and compare.
Have someone mash the pedal and you observe / take measurements of throttle movement underhood; adjust pedal, repeat measurements and compare.
Veteran Member
Joined: Oct 2014
Posts: 1,092
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From: Scotland
It is important that the stop is adjusted to allow the cable full movement of the attached mechanism, in this case the traction control throttle relaxer, no less no more. The temptation to pull the cable a little harder is natural, but will more likely result in a broken cable or throttle relaxer or both. There is a procedure for the adjustment in JTIS if I remember correctly.
Member
Joined: Jun 2014
Posts: 33
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From: San Francisco
Sounds like you're referring to the kickdown switch, which is adjustable.
#13 here -- Accelerator Pedal and Cable - Parts For XJ Series from (V)720125 to (V)812255 (X300) | Jaguar Classic Parts UK
#13 here -- Accelerator Pedal and Cable - Parts For XJ Series from (V)720125 to (V)812255 (X300) | Jaguar Classic Parts UK
Senior Member
Joined: Jan 2009
Posts: 379
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From: The Netherlands
The kick-down switch has 2 parts, the upper black plastic knob and the bottom part which is the electrical switch.
To adjust it correctly you need an OBD2 reader that display throttle opening %
Push on the gas pedal until it make light contact with the knob ( light meaning that the switch do no "click"
In this position throttle opening should be 90%
If not screw the knob in if the reading was less than 90% and unscrew it if the reading was more than 90%
To adjust it correctly you need an OBD2 reader that display throttle opening %
Push on the gas pedal until it make light contact with the knob ( light meaning that the switch do no "click"
In this position throttle opening should be 90%
If not screw the knob in if the reading was less than 90% and unscrew it if the reading was more than 90%
Joined: Feb 2014
Posts: 20,532
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From: Crossroads of America
To adjust it correctly you need an OBD2 reader that display throttle opening %
Push on the gas pedal until it make light contact with the knob ( light meaning that the switch do no "click"
In this position throttle opening should be 90%
If not screw the knob in if the reading was less than 90% and unscrew it if the reading was more than 90%
Push on the gas pedal until it make light contact with the knob ( light meaning that the switch do no "click"
In this position throttle opening should be 90%
If not screw the knob in if the reading was less than 90% and unscrew it if the reading was more than 90%
Thanks for the excellent explanation of the proper way to adjust the kickdown switch.
I would add that before adjusting the kickdown switch it is a good idea to adjust the throttle cable to remove any slack that may developed due to stretching.
If you don't have an OBD scanner that can read the throttle opening, you can do a rough setting of the kickdown switch by adjusting its height so the switch clicks just before the cable cam on the throttle butterfly valve shaft reaches its wide open stop screw.
Cheers,
Don