lik i dont know. or understand how. but i hav a 92 with a 305 motor. i loosen the plate that holds the distributor. hook up the timing light and set it to 12 dg. then as i hav the car running the timing goes bac to 8dg. im guessing the ecm is reseting it bac to spec ??? but now idk how 2 bypass that and need help... and not b a bother, but i put a cam in with 462/469 lift. where should i actually be setting the timing too ???

 

Get a Haynes auto manual from your auto parts store and go through the tune up section. I am only farmiliar with an '84 305 which the computer wire must be disconnected from the distributor inorder to set/change the "baseline" timing. I dumped the computer except for trans lockup and speedo operation in the '91RS I put the '84 305 in using a D.U.I Performance Distributor and Edelbrock intake/carb, "old school". (works great ) Try getting in touch with any of the companies listed in the advertising section of you favorite hotrod mag that do custom chips for your application. I'm sure they can dial in a chip that will work for you and adjust your timing to an optimum curve.

Sorry I could'nt be more help,
Good Luck,

Roy

 

Unless somebody removed it, you should have a "Vehicle Emissions Control Information" label under the hood that gives you instructions. You want to bypass the Electronic Spark Timing by unplugging (in-line connector) the tan with black stripe wire. That wire comes out of the black plastic corrugated conduit on the passenger side, between the strut tower and firewall.
Oh yeah, and leave the wires plugged into the distributor.

 

Can anyone list the steps to advance the baseline timing on my 91 Camaro Z29 305. I know to disconnect the ESC wire but I understand you need to disconnect the battery as well.