Iam hoping someone can help me out with this, Just installed my HSR in my 88 Iroc and had a surging issue. I took it to my buddys Dyno shop to get it scaned and found that the computer was reading the RPMs as double what they were on my Tach. He said to check all the wires from the Distributor to the ECM and make sure there all good. So in doing so going off a Haynes manual its telling me pin location B3 should be BLK/RED, B4 should be WHT {EST line} B5 PPL/WHT D5 TAN/BLK. My WHT est wire is going into D4, so iam thinking it was a typo in the book. Can anyone with there ECM down check to see where there White wire runs to, its the only solid white wire in the harness to the ecm. I check the MSD to make sure the switch didnt get bumped to 4cyl as well. Thanks

 

The wiring diagrams on Autozone's website show the WHT going to D4.

 

Thanks, i ended up running into a friend that has a TPI car last night so i raided his harness. I found out my coil was bad on one side so i think that is what was doubling my ecm reading of rpm's.