Initial timing challenges

[JohnJL]

I am having a problem getting timing observed on the timing light to agree with Megasquirt.

I set the distributor at about 0 degrees timing based on where the rotor is lining up to the #1 plug.

I can start the car and it idles ~1400 pretty steady with ~13:1 AFR.

I set tunerstudio to "locked timing" at 10 degrees.

When I check with a timing light it shows advance at around 50 degrees ?!?! I tried 3 different timing lights with the same outcome.

The trigger wizard is open and when I increase the offset up to ~30 degrees the motor starts and runs OK, and the timing mark progresses towards (but never quite to) 10 degrees. Above 30 degrees offset the motor dies immediately.

I seem to be chasing my tail but I need some help, I've never had this problem before. I did check and follow the steps on the MSefi page : https://www.diyautotune.com/support/tec ... se-timing/

I did check with the crank pulley manufacturer that the marks are correct and verified cam timing.

Thanks for the help please and thank you

The motor is a 1976 911 with a 12-plug JBracing distributor. Ignition triggered by a vr inside the distributor that has timing locked.

[JohnJL]

Nevermind, I figured it out. I'll share what I found though...

The rotor contacts are fairly narrow, so I had to gradually clock "back" the distributor gradually and then adjust the timing offset using the trigger wizard. I think because the rotor tips are so narrow that adding too much offset in the right direction was trying to fire the #1 cylinder before the rotor was within reach of the rotor to the cap terminal.

I have a surging/oscillating idle now to deal with still.