I've got an 87 turbo. I've just installed my HKS VPC and F-CON. I've already spend over $300 on the harnesses I needed, because the harness that was included was for an 88-92 and not my 86.5-87. Where is the ideal tap-in location for the b-map sensor? I've tried several existing vacuum ports, but nothing makes the car run right. It will either run VERY rich, or idle well but stall when you press the gas. Could the chip be bad? I really don't want to spend more money on a chip if that's not the problem. Or is it just the tap in location of the map sensor???