92 f150 running problems

I have a 92 nite 5sp 302. It has started running a high idle until it warms up as well i have noticed that the temp guage is not movin at all. It also seems to have become gutless below 2 thousand rpm on the highway and really hard on fuel. If I get the revs up above 2000 the thing works fine.:banghead:

is check engine light on? sounds to me like you may have a bad coolant temp sensor.

No check engine light

No check engine light
if the pcm picks its temp signal up from the same circuit as the gauge then the system will never go into closed loop causing it to ignore the o2 sensors which will in turn lead to driveability problems. i would start by trying to find a wiring diagram that shows the temp sensor circuit(s) and see if they share the same circuit

There are 2 sensors for your coolant. The one for the gauge is a one-wire sender located in the coolant runner of the lower intake. The PCM sensor I believe is located next to or in the t-stat housing and is a two-wire sensor. From what it sounds like, your thermostat might be stuck open, causing the engine to run cold, which explains your gauge not responding and the high idle trying to warm up the coolant faster. Good luck and I hope this helps.