1991 FJ80 3FE - Unplugged TPS

Sep 13, 2020
New York City
A few months ago, while on a 10-hour drive, I noticed that my 91 FJ80 was "bucking" somewhat violently after a while. No CEL but did have a code 51 previously for TPS. I had recently replaced my cats and o2 sensors as well. Pulling over would reset the issue somewhat as it would only start after an hour or two of highway driving. Since then I hadn't done any long distance driving so wasn't able to recreate the issue. More recently however, I was having a start issue where the engine would turn over but not start until the second try with some priming on the gas. I was also having stumbling at start / stop and go traffic at low speeds. This would happen again more frequently when warm, ie. drove a few miles, stopped, and then upon restart.

All this plus the truck had been very sluggish overall, with a very bogged down feeling accelerating through lower gears. I had forgotten about the TPS code and after a good bit of searching on the forum, thought that I might be dealing with something fuel related ie. clogged fuel sock or bad regulator/damper. Then seperately I came across a thread where a guy who said he'd been having the bucking issue decided to unplug his TPS and that fixed it. So I did that, just before a 3-hour road trip this past weekend. No bucking, no stumbling, no starting issues plus overall smoother/faster acceleration. Runs better than ever. Safe to say I need a new TPS, but wanted to share this in case someone's having similar symptoms. Also wanted to see if you all think it's ok to leave the TPS unplugged for a while or I should get on replacing it. Plus I saw something about needing to adjust a new TPS to spec, is that the case or will it come ready to plug and play. Thanks!
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