I have an 85 T-A with a temperature gauge problem. I have replaced the stock 305 with a 350. My friend and i have gotten almost everything hooked up and the car is running. When the car is started the temperature gauge goes from 100 degrees to maxed out and keeps jumping all over the place it does not stay in any one place for very long. Everything has been replaced on the motor except the things like the starter, alternator, a/c compressor, and power steering pump. The engine is getting hot but he says he doesnt think its getting over 220. I dont know alot about it all. He has never seen a temp gauge do that and doesnt know what the problem is. We are bypassing the computer and all of the emissions equipment. The engine is not making any strange noises it sounds like it is running fine and the oil pressure is around 50-70. The strange thing is that when he was adjusting the timing the temp gauge was fluctuating with him advancing and retarding it. The timing is now set but the temp gauge is way past the max temp of 260 it is as far as the needle would go. It would go down to 100 degrees when the engine had been running and was at its normal operating temp. I hope there is someone out there that can help I am hoping to get the car runniing before I go back to work next week. Heckuva way to spend a vacation huh? Thanks in advance for the help. Oh yeah i read a post about crazy temp gauge and the car running rough the knock sensor is in the block but not attached to any wire I couldnt find one to go to it in the engine compartment. and the wire to the temp switch on the head was stripped so we patched it with some more wire. The carb is edelbrock performer 600 with electric choke it says not to use it to replace a computer controlled q-jet but everyone says it will work fine. I dont know im just a dumb*** I guess. LOL Thx in advance again.

Well I am pretty sure the temp gauge is the wire grounding out and I figured out reading around the site that since I changed my carb to a non-computer controlled one that Im gonna have to swap out the distributor for one with vacuum advance that is why we had such a hard time setting the timing duh.... Well if anyone has any advice let me know it never hurts to learn something right.
Thx everyone

 

Make sure your coolent system isn't low on water and buy a new temp sending unit and check the engine ground straps.

 

thx the gauge is not going crazy anymore it is not working at all now I am going to get a replacement and try it again. I think the first one just fried itself or something. Now i cant get my alternator to charge and i bought a new one. I have the blk/red combo plug hooked up and the red wire from that going to the back of the alternator but do i need the main ground to the battery on the alternator or the motor or where. and is there another wire that i need to hook up to the alternator. There are only the connections for the red/blk hookup and the return that branches off from the red wire in the harness. Its a 85 T/A vin G I am thinkin there is a brown wire somewhere that comes from the volts gauge and goes to the alternator but i dont know where to put it. I have checked all the grounds that I could find and sanded down the connection area and ground wires and hooked them back up. I am going to post this in the electrical forum but if you have any ideas post them on either post I will check both. Thx again Ryan I will check all of the above.