90 XJS Throttle Position Switch Adjustment

[Michael J.]

This switch is mounted on the "turntable" that the throttle cable connects to and the two rods for the throttle valves, is activated when the switch roller rides up on a ramp as the turn table turns. I can't find a procedure for how to adjust the switch so that it activates at the right point. The switch is in parallel to the blue vacuum switch.

I am interested in the measurement of the gap between the switch roller and the ramp when the throttle is closed.

Would someone please measure the gap that they have and post a reply?

 

[Doug]

Not that I'm a final authority but I don't think there is an adjustment spec. As long as the switch closes when it hits the ramp, you're OK.

Cheers
Doug

 

[Paul Johnson]

Am sure you've solved this by now, but just in case, and because no can stop me, I get to jump in. Don't know the '90 Jags personally, having left the marque about ten years earlier, but these switches are signals to the ECU that you've broken idle, so that is all you need it to know. Some will have a wide open throttle position as well. If it is a potentiometer rather than a switch, then it'll measure the full travel, in which case, set the signal to the universal 0.5v closed, and it will show wide open at about 4.5v.

 

[Michael J.]

Since this string was posted, I downloaded Kirby Palm's Book "Help for the XJS Owner" which says that the potentiometer needs to be set foe .32 and .36 v measured with the ignition on and between red and yellow leads. For more on how things have turned out, or rather haven't yet, see the current string on 90 XJS High Idle.

Thanks for your input.