Brought Dart to shop to fix idling issue and car runs like s**t!
just wanted to ask to clarify AJ that I shouldn’t stay with the mopar electronic ignition and no vacuum advance? I should go back to the original distributor and points?
Not at at all; but a streeter needs a working vacuum advance.
The mechanical advance system is only right once, namely after ~3600rpm at WOT.
You can sorta get close at idle.
You can get real close from stall to 3600 at WOT.
But the rest of the time, it is DEAD-wrong.
So, on a 60 minute cruise around town, how many of those will be at WOT?
Let's say you are exceptionally brave, and nail it once every 4 minutes for 4 seconds, that comes to a grand total of 1 minute out of 60 , or .0166% of the time. So then 98.33% of the time, your timing is all wrong.
As an example, when your engine is cold and not on choke, it might want 50* of idle timing. Obviously, you cannot ever give it to her, so you do the best you can, and crank it up to 14*, Now you know why it idles like it does.
But lets say once it warms up, she is happy with 40; and you still can't meet the need.
Lets say you put it in gear and give it some throttle ,just enough to tip the V-can all in, and you have modded your Vcan to get 22* out of it. Say you now hit 2000rpm, and the mechanical is delivering .8* per 100rpm beginning at 1000 rpm, Ok lets add it up; initial of 14 + 8* mechanical + 22 in the Vcan comes to 44* and that might just be close.
So now you continue to accelerate, the throttle is open far enough to accelerate to 60mph at a normal rate, and as you cross 2800rpm, the system is dialing in; 14Idle + 14M + 22V=50, hyup sounds close. But say you hit second gear and want to accelerate a lil more briskly. Just a lil. So now in second the Rs drop to 1700.; so 14 + 6=20 , and say half the Vcan dropped out so 20 + 11=31 perfect. So now you need some giddy-up and are doing 32 mph in second. when you nail it. The trans drops back into first, the Rs climb to ~4200,(with 3.23s), and the timing drops to
14 + 20 + 0= 34* Badaboom!
This is just a theoretical curve; your engine will likely want something completely different.
But now you probably understand the importance of having a working Vcan.
It is NOT JUST for fuel economy at hiway speed.
Your three timing systems are constantly working as a team, struggling to create the maximum amount of cylinder pressure and deliver it to the crank, when it in the best possible position ATDC to receive it, and then to send it out to the tires.
Failing proper timing; you will have to cover the sags and hesitations, with a rich mixture, and pump-shot. And you wonder why your fuel-economy is so lousy? Well there yago.
But just to be clear;
I would never advocate going to a points trigger, not that they don't work; I just never would use one on the street. and
The Vcan does nothing at idle, and nothing at WOT.
What I would do is get a D with a working Vcan. Even new, they are not that pricey. But Hey, you don't have to get it right away.....
