98 transport ..short?

Ok this is my first post so hope i dont miss anything. I have a 98 transport with a 3400. Out of the blue it will jump up in rpms 1500 in gear and will climb as far as 3k in park. Also at the same time this happens my gas gauge will peg above full. I am thinking its a short, bad ground something around there im just not sure where to look that will make them both act up at the same time. Any advice please let me know thx

I'm not an expert, but have been reading these posts alot.

Make sure you look under "Montana" in addition to transport. You might even consider posting there. There is a connector under the driver's seat that gets corroded. You might want to inspect it.

http://www.automotiveforums.com/vbulletin/showthread.php?t=980423

The rev of the engine RPMs is strange. I wonder if it has to do with your fuel pump. The fuel level sending unit and fuel pump are one assembly. Do you think your fuel pump is kicking on high and cranking up your fuel pressure?