ok heres the deal, ive just built a new motor for my LS. it ran fine for two days. the other day it began to overheat while idling in the driveway. so i shut it off. replaced the radiator cap, and checked the thermostat. it all works fine. the grounds on the motor are all in place, the one from the battery to the trans, the valve cover to the rad support, and the grounds on the t stat housing. when you start the car it will turn on and idle like normal, but when it begins to heat up it the temp gauge will start to flucuate between hot and normal, and when you hit the window down switch it will dim all of the lights on the gauge cluster, and the temp needle will move towards hot. the ECU is also throwing a CEL for the ELD and the TPS. i have no idea what is wrong. battery is brand new and this just happened out of the blue. please help i was supposed to go tune today and had to cancel. its a 92 LS .

 

Well common sense would dictate that you check your wiring first and get rid of whatever it tripping those codes. The code for the ELD should help you in the right direction. Do some research if you don't know what it is..