Intermittently my (5 speed) XJ will loose power to the point of barely idling (roughly) or flat out stalling. I found a broken vacuum line and fixed it but a week later it did "it" again. It will start and rev up to about 2K then drop to a very low, stumbling idle or stall. I have replaced the Idle Air Controller and Ox. sen., thoroughly cleaned all grounds/battery connections and done a major tune up with highest quality parts 6 months ago, prior to this (and between failures) it runs/ran fantastic. (Even good fuel mileage) Both times I farted around wiggling connections, tapping on the IAC and TPS with no changes for 10-15 minutes restarting it. It finally starts, smooths out and acts like nothing is wrong. Could this be a sign of a failing TPS? (I've gotten a replacement just in case to install.) The symptoms seem more like my new IAC is acting up, I replaced it due to an intermittent steady high idle problem. (It was in very poor shape.) These old Renix systems can drive me nuts, it won't let me find the problem, but it got me home! Thanks for any ideas! Neal