I Need to replace Vacuum Advance *Got it figured out*

[TURTCEL]

Hey Fellow Tercers,

I posted a message under the parts section about this as well....I need a vacuum advance for my vehicle and I am having problems locating the correct one. I have a 1985 Terc SR5 4wd wagon with a 6 speed manual trans and has federal emmisions.

I have searched just about every site that I can think of to purchase a new vacuum advance for my car but I keep running into questionable products available. I need a dual diaphram advance for my distributor but all the units that I seem to come across are listed for automatic transmissions. I don't want to order the wrong part eventhough they look identical on the outside I am guessing the diaphram inside is different.

Has anyone else run into this problem? I would really like to order a new unit but if the only thing available is a known good used unit that any members are willing to sell that would be an interest to me if I can not locate a new one.

I do not have the OEM numbers off of my advance since it is still in the car and is on the bottom of the distributor so I am not able to see it.

Any help on this would be greatly appreciated. I would like to order this part a soon as possible.

Peace

[Petros]

they are all the same, or interchangeable anyway. they made a few changes to the design over the years, but they will interchange a work just fine. Also, the earlier ones have only two vac ports, the later ones have three. You can simply block off the extra port with a cap if you do not need it. It will work exactly the same way.

[TURTCEL]

Thank You guys for the clarification on the vacuum advance. I will order one today now that I know I will get one that will work for my application.

Peace

[keith]

Its not a dual diaphragm, just a dual port. The second port is a pass through to send the vacuum somewhere else, EGR I think. The third port is also a pass through so it can be blocked off as needed.

While you have it apart, be sure to oil the weights for the mechanical advance, I recommend a synthetic oil if you have some laying around. Do not use WD40 or any spray oil.

If you have 200k or more on this one, I would suggest that you just get a good remanufactured distributor. The center shaft bearing wears out and it has to be remachined, not something you will fix at home. A reman comes with all the goodies so in the long run, it is cheaper.

[dlb]

Its not a dual diaphragm, just a dual port.

i haven't had one apart to verify but i thought it must have two diaphragms since one port can hold vacuum while the other does not.

for lubing the dizzy internals, i've used bearing grease. i've found that the problems with gummed up dizzy's is usually in the signal rotor shaft so it must be removed, cleaned, and re-greased as well. it can be a real bear to get it off the governor shaft with all that dirty old grease but be persistent and ye shall be rewarded.

[TURTCEL]

I have actually been considering just getting a reman dist. I was all set to order a vacuum advance today but eventhough they have been said to be the same all the advances that I have found are for automatic transmissions so I have not submitted my order yet.

I was thinking that if I ordered a dist then I wouldn't have to deal with ant disassemly and possible loss of parts or wrong reassembly. Is there a specific aftermarket company that you have found to be better than the next for reman distributors? I have worked in the aftermarket autoparts industry for many years when I was younger but only had to deal with one or two reman companies. So, any suggestions of brands would br great.

I have a 1985 SR5 4wd wagon with Fed emmissions and a 6 speed manual trans. I figured that if the distributor comes with the vacuum advance then it would be for the manual set up and not the automatic if I specify before buying.

Thanks for the advice.

Peace

[xirdneh]

as long as it has two ports and looks like it has two chambers or sections or diaphragms or what ever you want to call them it will work
(basically a top and bottom port)

the three ported ones have two ports on top and one on bottom
one of the top ports has a much smaller hole and that one is for the high altitude compensator thing
when installed that HAC port is top inside

i cut one one apart about ten years ago
pretty sure there were two diaphragms in there

[dlb]

the three ported ones have two ports on top and one on bottom
one of the top ports has a much smaller hole and that one is for the high altitude compensator thing
when installed that HAC port is top inside

i want to add to this that if you don't have the HAC, you can just plug the third port with the smaller hole and the advance unit will work fine for you. i just did this on my project car.

[Petros]

I would not waste money on a reman distributor. Almost everyone I have seen is junk out of the box, as many Tercel list members will tell you. A used factory distributor is much more reliable than the junk remans. Or rebuild it yourself, take it apart and just replace what you need (o-ring, seal, bearings, etc.).

[keith]

I got a good one from NAPA. As far as I could tell, you need a machine shop to knurl the hole for the rotor shaft, I don't see a replaceable bushing.

[TURTCEL]

I don't quite understand what you mean by needing the rotor shaft hole knurled. Is this something that has to be done in order for an aftermarket vacuum advance to work on my factory dizzy? And what is the bushing you are talking about? Do you have a manual trans and could only get an advance for an auto, so fabrication is necessary to get it to work? That is my situation.
Peace

[dlb]

turtcel, the governor shaft (aka rotor shaft, i believe) is the part of the dizzy that connects via a gear to the cam shaft and rotates the rotor, which then passes each of the contacts in the dizzy cap and opens the circuit to send an electrical signal to each spark plug at just the right time. if that shaft has play in it and wobbles around, the dizzy is shot. as keith says, it could be fixed by a machine shop but i would personally just pull a good one at the wrecker. however, if the governor shaft in yours does not have play but the rotor does not have the spring-loaded counter clockwise rotational give that i mentioned before, it is still good. it just needs the grease to be cleaned out and replaced. i highly recommend doing this because remans really are hit and miss. if what i have can be repaired, i almost always stick with it—the devil you know, right?

you can replace the vac advance without doing any of these things but it's important that the advance mechanism not be gummed up, or it still won't work properly. don't be intimidated by the job or worried about losing parts. just do it in a clean area and lay the parts out as you remove them. it's really not a hard job. i've done several of them, no prob.

[keith]

dib has his opinion, based on what he has seen and experienced. I spent a ton of money on a distributor, coil, ignitor, vacuum advance etc only to have the shaft bearing go out a few months later. I could not get a core and put all the new stuff on it, I had to get a reman so I ended up paying for all those parts twice. I have only done this once and the reman I got from NAPA worked fine for another 100k miles. So my one and only experience with a reman was a good one.

If you want to verify the shaft bearing, turn the engine until one of the vanes on the distributor shaft lines up with the line on the ignitor. Check the gap with a feeler gauge, it should be 0.010". Now, with the feeler gauge in place between the vane and the ignitor, push on the shaft away from the ignitor and see if a gap opens up. If the gap opens up to where you can get a 0.016" feeler in between the ignitor and the vane, then you need a new distributor.

When it opens up to 0.017", the engine will shut down on you. It will be intermittent at first, but in short order, it will become much more frequent.

[TURTCEL]

Thanks for all the advise on the dizzy job guys. I will do all the diagnostic dizzy checking before I do anything. I will absolutley regrease and set my dizzy up the right way before putting back in. If the dizy has issues is there any place that I can order a dizzy rebuikd kit from? Or are dizzy parts available in individually based off of what I might find wrong?

Happy Holidays Everyone in the Terc Family.

Peace

[TURTCEL]

I just ordered a vacuum advance from RockAuto. Seems like they were the only source with a decent price with an advance available. It was said to be listed for a automatic trans but as far as I was told it should work just fine. Part should be here in 3-4 days and I will be undertaking my dizzy tear down, regrease, and reassemby.

Thanks again to everyone that has added information to my post, I am sure that with all the good advice my project will go well. I will keep you posted on the project.

When I do go through my dizzy and clean it up and grease it do I need to tear it completely down...as in pull gear and completely disassemble?

Peace