I am new too this, so i need some help with the tuning,
I bought a ecm with harness from psi for a 72 chevelle.
My problem is, when i hit the throttle hard it retard the spark down to 6-8 degrees. See the datalog.
The knock, MAF, MAP and O2 sensors are new!
Hope too get some help.
Regards
Christian Nybo
Denmark
72 CHEVELLE 6.0 4L80E nr3.hpl