Re: New purchase - low compression 50 psi on all 4 cylinders of 1978 470 engine
Tinerguy, please believe me when I say that I gave it my best before asking from the forum. I spent some time with the Manual #3 before posting my request earlier. As Don pointed out, there are no "points" on my distro. It has a single EM sensor (orange color in photo above) and I am unsure as to which of the four positions this would go. I took a close look at the distro shaft to see if there was a magnetic at the closest point of contact with the EM sensor and could not see anything. Kinda baffled and hoped that someone with a similar setup or experience would chime in.
I understand what you are saying and please don't think I was trying to ridicule you because I wasn't.
From the info you found, it looks like you can use the merc manual as a base. It says up to 30 degrees before or after TDC, well that's pretty much how a points distributor would go.
Since the link still doesn't answer your primary question of what position, I think it would be safe to assume that whatever the merc manual says still goes. Basically #1 is #1, regardless, just as I stated before. Points or electronic, it makes no difference. The only thing that matters is that the rotor is in the right place at the right time.
Anyway, from the pic you posted and what is in the merc manual, it looks like you are spot on. If it's still not running, then there may be problems elsewhere. Checking the coil resistance per the guide might be a good idea and make sure #1 is on a compression stroke and not an exhaust stroke.
So, if you have the rotor pointing to the #1 position on the distributor cap (as close as you can eyeball it anyway), with #1 cylinder on a compression stroke, and the thing is wired correctly, you should get something from it when you crank it. Be it a backfire, sputter or pop, something should happen.
It's hard to track these gremlins down sometimes, I'm doing my best to help.
