just today i traded my 94 ranger 2wd for a 86 300zx turbo 5spd. it has 143,000 miles on it and shifts out great and turbo spools up fast its a little ruff around the edges but has potential. it has a few problems that i need some help with. the speedo and the rpm guage dont work. the speedo when im doin what feels like 30-35 is sayin 125+ and the rpm guage seems to only work in 1st gear if it is even right. also there is a plug in beside the throttle position sensor that it is not plugged into anything and there is nothing i can see to plug it into and it is running a little ruff like surging at idle and when revved up it takes a min to get back to normal then it starts idling high and surging again. i am new to these cars i have herd alot of great things about them. so if anyone can help me please do thank you