Alright I’m trying to properly nail down how my 360 runs in my ‘73 D150 so I can actually start to make runs to the store with it. I feel like it’s about 90% there..
So essentially the whole ignition system is replaced already with the exception of the pigtail to the ignition module. I also went to a 4-pin module in place of the 5-pin. The main symptom I’m fighting is a bounce in the timing reading with my timing light, I’m talking like a 5-10 degree swing for a couple of flashes of the light. The weird thing is yesterday I added some additional grounds to the system just to eliminate variables and the bounce dropped to less than 1 degree so I thought it was fixed. Tonight I went to confirm my actual timing and vacuum at idle and it’s back to doing the same thing.. starting to lose my mind on it.. ideas of what else to check that may cause that issue?
My second problem that I will, I’m sure, rectify after I nail down the timing bounce is actually timing the motor. So with the vacuum advance kinked off I fired it up and set my initial at 1000rpm, right around 13-14 degrees, idled nice, all in was right around 35 or so. Then I added back in the vacuum can and it’s pulling around 30 at idle and 40+ when throttled up. Motor still idles well, runs cool, doesn’t stall in gear and runs down the road, the only sign it has of anything off is a miniscule stumble if you try to drive just barely off idle. Should I attempt to back the timing off just a few degrees and shoot for the all in number with the can? I’d like to keep the vacuum advance in the system as it does seem to help overall.
Any and all input is appreciated!