distributor questions

['71 Dart Custom]

The diaphram in my vacuum advance is leaking. A friend told me he doesn't ever hook up his. Says it runs better without it. I unhooked mine and plugged the hose and the car certainly idled better, but what effect is this going to have on how the engine runs and do I have to replace the whole distibutor or just the diaphram?

 

[nothingbutdarts]

You should be able to go to a parts store and buy a new one.

It really shouldn't idle better unplugged. Unless: the hose is not connected to the correct port on the carb as most vacuum ports are only active off idle.

The vacuum advance helps gas mileage.

 

[RedFish]

Idles better is becuase you plugged the vacuum leak / corrected fuel air mixture.
You can replace only the vacuum servo if you can find one. Some of them aren't readily available.
Some guys do adjust the base timing to prevent pinging under load when running without the vacuum advance. One thing leads to another though. 14 to 18 degrees BTDC can stop the ping but cause harder to start. Then lower the curb idle to prevent run-on or diesel at shut down. Shade tree tuning at best.
A reman'd distributor will include a new advance servo.

 

['71 Dart Custom]

You should be able to go to a parts store and buy a new one.

It really shouldn't idle better unplugged.

I plugged the port, then it idled better.
So I shouldn't have to buy another distributor? I'll have to pull it though, I'm sure. Doesn't look fun considering the location. Oh, well. At least I can replace the plastic drive gear. That caused the demise of another 225 I used to have.

 

['71 Dart Custom]

Idles better is becuase you plugged the vacuum leak / corrected fuel air mixture.
You can replace only the vacuum servo if you can find one. Some of them aren't readily available.
Some guys do adjust the base timing to prevent pinging under load when running without the vacuum advance. One thing leads to another though. 14 to 18 degrees BTDC can stop the ping but cause harder to start. Then lower the curb idle to prevent run-on or diesel at shut down. Shade tree tuning at best.
A reman'd distributor will include a new advance servo.

I was writing my last post while you posted this. I'll start pricing distributors.