Question #2 vacume not working.

[Anonymous]

Question #2
I have the auto lite 1100 carb with a single vacume distributor. I could never get the vacume avance to work. I check to see if it moves inside the dist with vacume and it does. I also have vacume comming from the carb to. At the moment I running with out any advance and it has no pickup. Also if I change to Duraspark II system will I need to upgrade carb?

 

[BIGREDRASA]

How do you check to see if the advance mech works inside the distributor?
Do you have a vacuum pump? A vacuum pump would be a good investment to see how much advance you get at a given inches of mercury. 8)
All I can think of is that you have a bad diaphragm.

 

[Anonymous]

Well actually I sucked on it!! I replace the diaphragm when I bought the new distributor. If I buy a vacume pump what would be the procedure on checking it?

If I upgrade to the Duraspark Distributor will I need to upgrade carb?

 

[BIGREDRASA]

The vacuum pump would let you know how much advance you have at the different vacuum levels. The diaphragms are adjustable with a small allen wrench, so you can get more or less advance at a given vacuum. 8)
The vac pump is also great as a one-man brake bleeder.

 

[Anonymous]

Sorry if this seems simple but I nevered messed with the vacume.

what are the different levels? How much vacume should I have if I was measuring coming from the carb?

I am assuming that I should conect the vacume pump to the carb and measure when idle and at different rpms. Also check the timming while applying vacume with the pump to the distributer see how many degrees it advances.

If I remember correctly the book calls for a 6 degree at base with out advace, so how much should it go up?

 

[BIGREDRASA]

Check out my recent post on the FSP Lounge, before you hold me accountable.
Seriously, I can't find the specs right now; but in general, you need to know what your max engine vacuum is, and make sure you reach max vacuum advance at or below that level.
With the engine running, and vacuum advance line plugged/capped, connect the vacuum pump to the dizzy's vacuum port. Record the number of degrees additional advance obtained as you increase vacuum (say at 5" Hg., 10", 15", and 20"). You should probably not exceed 18 or 20 degrees additional advance at full vacuum. In addition, you can probably stand to advance initial setting to 10 or 12 degrees, unless you get a lot of pinging, then back off until it stops pinging (knocking). Total advance, initial plus vacuum, shouldn't exceed 35 or 38 degrees.
I'll have to defer to someone who has the specs, cause I sure can't find them.

 

[BIGREDRASA]

Here's a reply from BarryB on the Classic Mustang Forum <fomoco.com/mustnag/forum>

"RE: What year, engine, application?
by Barry B 6/24/2003, 2:40:09 AM
Oh, ok. Here's some specs on a C5DF-K used on a 170 and 200 with an auto.

RPM Advance Vacuum
800 3/4* - 1 3/4* 0.79"
1200 3 3/4* - 4 3/4* 1.90"
1600 5 3/4* - 7* 3.00"
2000 7* - 8 1/4* 3.80"

Note these are distributor rpm's and degrees, double them for engine rpm's etc."

Personally, those numbers shock me, as they seem to be pretty low, specially only 3.80" Hg.

 

[Anonymous]

Thanks for all your help!!! I should get the mustang started this weekend and test out the clutch. I will then try to fix the timming and advance next. I all want to upgrade the duraspark next so that should be some time next month.

This is such a great Forum!!! I wish I had knew about this place 10 years ago when I first got my mustang!!!

 

[BIGREDRASA]

I, myself, would find a later dual advance dizzy, and hook up the Pertronix II with Flamethrower coil. 8)
Just remember that your carb is meant to work with the Loadamatic dizzy, not a regular dual advance dizzy. You need to swith carb and dizzy.

 

[Anonymous]

I also will be upgrading the card to a 2bb hopfully. I guess this should all be done together. I came accross a 2bb webber with adaptor and linkage and was for sale for 200.00. Is that a good deal?

 

[Anonymous]

Another thing, how can you tell if your dizzy is a loadamotic? I bought one a few year from a parts store and just figured it was the correct one.

 

[BIGREDRASA]

Take the cap off, and see if there are two springs on the breaker point plate. I think that's the surest way. I was shocked at the low vacuum readings quoted for the Loadamatic application. Those numbers wouldn't budge the regular vacuum advance.

 

[BIGREDRASA]

Me, I' rather rebuild anything smaller and lighter than a C-4 myself. Even if it gives me a reason to buy new tools and manuals.
Check the part number on your dizzy. It may well be a dual advance unit, which is better than the Loadamatic.
But if it is dual advance, you need a different carb. Search the various other posts for a good unit.

 

[Anonymous]

thanks. I love new tools and plan to buy a vacume pump this week

 

[Anonymous]

I checked last night and there were no springs, I guess thats why I could never get it to work right with my Autolite 1100 carb!! Well it won't be important because I plan to get the duraspark system any way!!!