Timing Curve on 360 in an RV

nm9stheham said

If I am reading this right, the new system base timing is verified by 'locking' the timing in the software at 12* and verifiying on the damper marks with a timing light.

But that is a different matter from locking the mechanical advance mechanism in the distributor. Is this the stock distributor being used for this new system, or a new distributor being provide with the new system? I guess this is a dumb time to ask this but what EFI system is this? Pro Flo 4, with a new distributor?

Click to expand...

ProFlo4 Hall effect distributor that has no internal mechanism to vary timing so the ECU controls timing.

Also I have verified the rotor is at the #1 distributor cap terminal @ 12*.

I do know what happens when the factory pickup is connected backwards and this acts very similar. I was saying backfire but it’s actually fuel igniting in the exhaust. Unless the distributor pickup is wired incorrectly from the factory It’s hooked up correctly as it can only plug in one way. I have 2 different engines that act exactly the same.

Also not using any aftermarket multi spark box just the internal ignition within the EFI system.

One last note, the ECU uses timing Along with the air control valve to control idle speed so timing jumps around some at idle.