1976 2.0L D-jet, distributor vacuum Options

[Ron914]

@emerygt350
I was asked my a member helping me with my high idle /vacuum leak problem how I currently have it hooked up .This is the diagram I am using .

[emerygt350]

Hmmm... I put a new to me fan on mine when I rebuilt it and it was from a later bus type 4 and it had no marks. I marked mine by lining it up with my original and then tdc while it was in the car. You may have the same kind of thing going on. I would verify TDC and mark it yourself. Not sure if the flywheel can be 180 out. I mean anything is possible I guess.

And your mps should hold air much longer than that. It needs to withstand 17 at a minimum anyway. Holding at 10 seems odd to me but it doesn't really matter in your case.

And I am not sure if that kind of a leak means you are out of luck or not. I think I would start looking for a kit and while that is going get that timing mark figured out.

So many questions. I would get cylinder 1 at TDC using an Endo scope or a chopstick (using the tire in 5th gear technique). Verify the mark on the flywheel, and verify the position of the rotor. Then I would make a nice new mark on the fan and time the engine.

[Superhawk996]

And your mps should hold air much longer than that. It needs to withstand 17 at a minimum anyway. Holding at 10 seems odd to me but it doesn't really matter in your case.

(IMG:style_emoticons/default/agree.gif) Somewhere in these threads you’ll find a bled down time range from something can’t be less than 5 in Hg starting from to 10 in Hg (Brad Anders site) in less than a minute, to using like 10-15in Hg and having it hold without dropping at all for 10 minutes and if I recall the automobile Atlanta site says something like should hold indefinitely. Truth is somewhere in between there.

Personally I believe longer is better. There are so many threads where people struggle with a diaphragm that is hairline cracked that it isn’t worth it to me to be chasing your tail if it seems borderline. Once you see how it’s all built it’s easy to see how a diaphragm can hold at lower vacuum but when the diaphragm deflects and leaks more at high vacuum (ie idle and deceleration) it could cause problems.

Just pulled 15 in Hg on a unit I rebuilt about 6 months ago. Hasn’t leaked at all at 10min mark as I write this. Just wanted to re-test it before giving you numbers I can support with data and a video.