Odd problems
 

Ok so today i went outside to start the FC and it cranked but wouldnt fire. I had this problem before, but fixed it 2 days ago. (Bad connection between the power wire on the battery to the fuel pump)So anyways, I fixed that but now 2 days later the car was turning but not firing. I checked the voltage at the fuel pump and got 12 volts, so I pulled the fuel pump and tested it with a 12 volt battery and sure enough, it worked to. After I reassembled everything, I tried to start the car again and it started! However, 2 or so minutes later when i returned I noticed that the temp gauge was pegged on H, so i freaked and cut the motor. I popped the hood to see if i'd blown a line, but i found out that the car was still very cool and that the radiator hoses were only warm. So i turned the ignition on in the car again and this time the peg didnt even lift off the C. WTF. So I tried to start it again and it wouldnt go, but when I touched the gas, the temp gauge would go up again, JUST FROM TOUCHING THE GAS PEDAL!?!?! All the way to H. Makes no sense, I know the car isnt overheated and that it has to be some sort of wiring problem. Any ideas would be greatly appreciated.

Also, incase you didnt catch it, the fuel pump has been rewired using a diagram I found on this website. It has worked fine for several months, so I dont think it was something I did with the wiring.

So what exactly are you asking??? Why your gauge is acting up or why the car didn't/doesn't start?

Both, and are they somehow connected. Also, I went outside this morning and the gauge is doing the same thing (spiking to H) when i turn the ignition on, even though the car is cold. Is this a grounding issue or something? Any help is appreciated.

I doubt they are connected at all, (why would they be?)

but I would be checking to see where the water temp wire got shorted first.

I'd be also looking to see what the voltage is in the car.