I have a 1990 YJ 2.5l TBI that has had a high idle issue for a while but it has recently got worse. Awhile back, it would start and idle around 1000, then kick up to 1600 about when it reached operating temperature. This was tolerable, but now it pretty much immediately goes to 2000 after start, hot or cold. The idle speed control or idle air control, not sure which is correct, but the little screw that is supposed to keep the throttle plate open a little bit to let more air in on start up isn't even touching the plate, and I'm pretty sure is broken considering it doesn't ever move, so I know that isnt causing it to idle high. I took a look at the throttle position sensor, which looked okay on the surface, but I probed it with a multimeter and it read 4.6 volts in but read 0 volts out. I think the out voltage is supposed to be 17% of the in voltage but even when I opened the throttle all the way, it continues to read zero. Would this mean that my TPS is bad? I'm relatively new to this so any help would be appreciated greatly. Thanks in advance.
