I did a search before posting and my issue is different than what I found. I have a '92 VX with a D16z6 that I autocross. Speedo worked perfectly in the VX. I have a '94 DX with 230K miles that's a daily driver. The D15b7 gave up the ghost. While I'm rebuilding it, I wanted to keep driving the DX since it has a/c and Georgia summers are brutal. So, I gave up auto-x for the season & took out the Z6 and put it in the DX. I swapped the entire engine harness on the Z6 & pinned the VTEC. I'm using the P28 that was in the VX. I even swaped the working cluster from the VX in the DX. All the gauges work except the speedometer. No speedo, no VTEC. I'm also getting REALLY crappy mileage. I'm sure its running rich. Does the Z6 require a certain fuel pump?