Well as the title states the I am having problems with the car starting and the tach is not working. When I go to start the car it turns over for about 10-15 secs. and then will start and run fine but the tach is not working??? The opti and the opti harness are new checked the plug and all seems fine there. Could it be the crank sensor... coil etc ?

Please help ASAP as I have sold this car and the guy will be picking it up soon and obviously I cant give it to him like this.