Just developed a problem with the throttle/pedal while freeway driving. 1997 XJR showing no CEL's. Just ordered a OBD2 reader but 4 days out. No problems with in town stop and go. During freeway driving, after backing off or coasting, you feel heavy pedal resistance, won't allow you to accelerate.
At first we could feather or press several times and it would return to normal. After a few days now you can only reset if you coast to a stop and turn car off and on, OR engage and disengage Cruise control.
But if you disconnect the CC connector at the traction control actuator (same unit) it still happens with no option except restart. Thought sure it must be traction control unit, but wires not shorted, works freely and makes no difference with it disconnected also.

Will Car run with ABS connector unplugged? Unsure how it could restrict linkage if TC and CC are both unplugged, but something occurs only at higher steady speeds. Will try that if it won't screw something else up.

Spent about 4 hours today searching posts, but did not find a similar problem.

Any Ideas?

 

Sounds like the so-called "throttle relaxer" to me. You can see it in the engine bay if you follow the throttle cable from the bulkhead towards the throttle body. In essence, it momentarily disconnects the throttle cable when commanded to do so by the traction control system, and then reapplies it once traction has been recovered. It has various mechanical and electrical elements, and JTIS describes how to set it up. Could yours have a fault?
For what it is worth, I doubt it would be the cruise control mechanism, as you can still use the throttle even when cruise is engaged.
I believe the car will run without the ABS connected, but obviously there will be no ABS, and likely no TC

 

If you have traction control, turn it off on the sloped dash switch marked "TRAC" and see if it still does it. If so, perhaps a binding cable going to or from the traction control unit?

 

Shelby,
I believe the traction control unit referred to by jagboi and the throttle relaxer are one and the same thing. The sticking cable thought is worth exploring, although I had dismissed it on the basis that you said the problem goes away (temporarily) when you switch off and on again, making me suspect an electrical dimension to the problem. The only place where the throttle cable comes into contact with electrics in a way which could cause pedal resistance is at the throttle relaxer.