89 pu 22re, 175k, all original internals except for TC replaced 30k ago w/ EB kit.

Twice this week the throttle stuck open in between shifts and sent the tach to 6500 before I could kill it. The throttle return spring seems ok and the stuck condition cannot be reproduced at will. I suspect the stuck throttle is a bad cable so will try replacing that. The cable is original. The casing is worn a bit near the evap canister and at another point towards the rear of the valve cover. I am located in NH and it's getting cold here. I also suspect the onset of cold weather has exposed a problem with a marginal throttle cable.

The last over-rev instance resulted in what appeared to be a cylinder miss and a valve knock. After idling for a minute the knock and miss went away. I let it cool down then went on a test drive and the engine seems to be ok. Normal power and no abnormal noises.

I suspect the valves floated and one got stuck open temporarily. Does this sound plausible or could some more severe problem be lying in wait?