Vacuum Advance

Hi,

I have a 1986 Ford Taunus GL.

I want to ask for help about vacuum advance source for the distributor. What must be the source for vacuum chamber on the distributor? Will it be ported vacuum (from the carbureteur) or manifold vacuum or just a combination of both?

I have a thermal vacuum switch installed under the inlet monifold (original! surprised me). It has three ports. One is for the input of ported (carbureteur) vacuum, one is for manifold vacuum and one is for output to the distributor (I think) or to the pneumatic control unit (because I have an original air condition on my ford). Do I have to use this for the vacuum advance source or do I have to use ported vacuum from the carbureteur?

I need help

Serkan

I'm not sure whether I can be of real help but I'll try to...

As your car has aircon I'd assume that the setup is a bit different than the ones we have - i.e. w/o aircon.

Typically aircon equipped cars have a so called IAC sensors - one you switch on the aircon the compressor kicks in, which basically consumes part of the power that the engines puts out. In order to avoid the that the idle RPMs drop / engine dies the IAC sensor or valve
" detects " the additional demand for power and adjusts the idle RPMs accordingly. Not sure but I guess that on a carbed vehicle the necessary source to determine the addtl. engine load would come off the vacuum - either from the manifold or the carburator itself...

How about testing it by first of all checking whether all vacuum hoses are tight andas a next step removing one by one ( with the a/c swichted on ) and see what happens - if the engine dies you just pulled the one that " delivers " the info that idle RPMs need to be raised to to addyl. engine load consumed by the a/c compressor.

As the coolant ga system typically is equipped with a pressure switch to kick out automatically at too low system pressure there should be no risk to damage the aircon.

Unless someone on the board has a smarter idea I'd do it by trial and error until you get yr engine running smoothly at idle.

Hope this helps some.

Regards

Egal

Zitat

Original von Egal
I'm not sure whether I can be of real help but I'll try to...

As your car has aircon I'd assume that the setup is a bit different than the ones we have - i.e. w/o aircon.

Typically aircon equipped cars have a so called IAC sensors - one you switch on the aircon the compressor kicks in, which basically consumes part of the power that the engines puts out. In order to avoid the that the idle RPMs drop / engine dies the IAC sensor or valve
" detects " the additional demand for power and adjusts the idle RPMs accordingly. Not sure but I guess that on a carbed vehicle the necessary source to determine the addtl. engine load would come off the vacuum - either from the manifold or the carburator itself...

How about testing it by first of all checking whether all vacuum hoses are tight andas a next step removing one by one ( with the a/c swichted on ) and see what happens - if the engine dies you just pulled the one that " delivers " the info that idle RPMs need to be raised to to addyl. engine load consumed by the a/c compressor.

As the coolant ga system typically is equipped with a pressure switch to kick out automatically at too low system pressure there should be no risk to damage the aircon.

Unless someone on the board has a smarter idea I'd do it by trial and error until you get yr engine running smoothly at idle.

Hope this helps some.

Regards

Egal

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I don't know what's IAC sensor, but when I open a/c system the idle drops. I've heard the same explanation from my brother that cars with a/c has a system like you've told. But I think mine doesn't have this system. I have a 2V weber carbureteur which has a ported vacuum output. The aircondition system work with pneumatic controls. The pneumatic system opens or closes flaps and this pneumatic control takes its vacuum from inlet manifold. But my question is that which of the vacuum soruce is good for distributor vacuum advance?

As I told above posts, I've made some extra search on the net and found some interesting informations, I'll write down them here, they're a bit long but take a look at them, I cannot decide whether to use manifold vacuum or ported vacuum for my vaccum advance unit???? What do you think? (also some writings about thermal vacuum switch)

**

Finally, vacuum advance was added for the purpose of further increasing timing at cruise. Most times it is connected to a ported vacuum sorce. This source has NO vacuum at idle, the most slightly off idle and then decreases to zero again at Wide Open Trottle (WOT). When cruising you can add an additional 15 degrees or more of vacuum advance, bringing your timing up to 55-60 degrees BTDC. This is the one to be careful of, too much and you can get detonation. Always stick to the low side to avoid detonation. Remember, it's just for gas milage.

One more thing to touch on. Manifold vacuum is maximum AT IDLE. All other times it acts just like Ported. If you hook your vacuum advance to manifold vacuum you will have 8-12 intial plus 15 or so vacuum for 23-27 degrees BTDC of timing AT IDLE. This will affect temp, though I'm not sure which way. I DO know, that most 1st gen birds came with a TEMP activated switch which actually switched the vacuum advance soure depending on the engine temp in order to keep it cool! The was specifically for long periods at idle.

**

Then there's the common CTO (Coolant Temperature Override) switch, which prevents the overheating that's associated with late ignition. It has three ports, one connected to the carb above the throttle plate, another to manifold vacuum, and the third to the advance unit. At normal operating temperature, the CTO allows ported vacuum to reach the distributor. But when things get too hot at idle, it routes the strong manifold signal to the advance unit, which kicks up the timing, cooling combustion and increasing idle speed.

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Ported Vacuum or Manifold Vacuum? Manifold vs Ported, its a never ending debate. Depending on the age of who you ask, and their own experiences you still have a 50-50 chance of one or the other. Ported vacuum is the choice of the factory. It is also my recomendation to start with ported vacuum. Depending on what level of modifcations you have done to your engine, your driving style, and your vehicles characteristics its a point of debate. Each presents its own set of advantages and disadvantages. My suggestion is to just try both and observe how your engine behaves for your driving style.

**

It is our recommendation that when you are using vacuum advance distributors, that you connect the vacuum advance to "full manifold vacuum". There are two schools on where to connect the vacuum advance line. On older applications the connection point was to "ported" vacuum. Ported vacuum means the port is drawing vacuum "above" the throttle blades in the carburetor. This means that as RPM increases, vacuum increases and in turn, vacuum advance increases. This was fine on older applications with high lead fuel and other ancient engine designs. Using this set up today can cause detonation problems, overheating, and other grief.
With our suggestion of using the vacuum connection to full manifold vacuum, the port will be drawing vacuum below the throttle blades. A good running street engine will have a measured vacuum at idle between 14"-20" of manifold vacuum. Now, this will give you a ton of advance at idle, but as load increases (vacuum drops) you will take timing away. This is excellent for the faster burning fuels offered today as well as in the fact that when you put your foot into the throttle and get the RPM building, you DO NOT need or want additional timing. On a RV or tow vehicle, when you put your foot into the throttle and downshift to climb a grade, you DO NOT want added timing that will slow the vehicle and add heat. You want the added timing for subtle throttle response, and low load engine efficiency. So, when you are cruising at freeway speeds or in town traffic, you have the added timing to save fuel, add throttle response, and overall give you a better feel.
**

The ported vacuum plumbed to the vacuum advance is designed to apply
extra advance to the engine during light load, medium speed engine
operation. This works because the mixture is dilluted with exhaust gas
and the load is light; both conditions lead to slow flame propagation, thus
the engine can stand more advance. The ported vacuum is achieved by
locating a small vacuum port such that it will be exposed to manifold
vacuum as the throttle first cracks. As the throttle opens further,
the vacuum in the area is reduced and the signal goes away. Ported
vacuum does not exactly match what the engine needs but like all mechanical
advance schemes, is an approximation that works OK.

**

The Thermal switch is for your vacuum advance on the distributor. One port goes to the distributor itself, and one goes to ported vacuum (which is connected to the distributor normally) and the other to manifold vacuum (which takes the place of ported vacuum under overheating conditions)

**

The TVS supplies manifold vacuum to the vacuum advance canister when the engine overheats at idle, to help cool the engine down. In normal conditions, the TVS supplies ported vacuum to the dizzy's vac advance canister.

**

According to the TSM, the distributor vacuum advance needs manifold vacuum when cold and ported vacuum once the engine's warmed up. This switch is handled via a coolant temperature override (CTO) switch (aka "ported vacuum switch") plugged into the thermostat housing.

**

on newer models - as I mentioned earlier try the various vacuum sources / connections you have - the engine will either die due to low RPM when you hook up the wrong vacuum line, or it will run like shit under acceleration due to wrong vacuum advance on the distributor.

Are there any other sensors on your car ( throttle position sensor ? ). I'd imagine that the smple lenght of the old vacuum lines you should get a pretty good idea which line is supposed to hook up where...

Regards

Egal

Today, I've adjusted my ignition timings and also looked for other sources of vacuum. My car is running on duel fuel system, LPG and petrol. So my static+mechanic ignition timings are 15° at idle (850 RPM), 18° at 2000 RPM and 23° at 3500 RPM with vacuum advance the timings are 23° at idle, 35° at 2000 RPM and 40° 3500 RPM. During this adjustment I have used the thermal vacuum switch installed under the inlet manifold. When the engine is cold the vacuum is from manifold and when it's warm, vacuum is from ported (carbureteur) vacuum source. When I start up the a/c on idle (850 RPM), it suddenly drops to 750 RPM but motor didn't stop but it was pinging. Because of the a/c working when the motor gets too hot, the thermal vacuum switch turns the vacuum source to manifold and this causes an increase in idle (because of the vacuum advance) to cool the motor. I couldn't find any IAC sensor or anything other. But I have a pneumatic control system for the flaps used in aircondition system. when I looked at the system, I've found that a vacuum switch and a hose was left open. When I move the heating/cooling slider inside the car to the cooling part this switch comes on and vacuum appears on the hose. I think there must be something attached to this hose, but I don't know what!

I've gone to a climate a/c technician and he told me that this system is a demode (very old) a/c system, but when he make some pressure and temperature measurements he's very surprised, because even it's an old a/c system, it was working good, even closer to the modern a/c systems. :) I like this! He didn't know much about ford taunus and couldn't give me information about the empty switch and the hose and IAC or other sensors and etc.

Anyway, I couldn't find any information about Ford Taunus with a/c on the net. So I'll search further to find some information. If you have info please help me.

By the way, thank you for your help and informations :)

as I do have a similiar problem on one of my cars ( unfortunately not a FORD ) I'm turning into a kind of self educated a/c specialist - this POS has a similar setup as your Taunus has - i.e. vaccum operated flaps - which is nice as long as it works if not it plain sucks .

If you loose vaccum plug the line - otherwise you can adjust yr ignition timing and it will not work out. You already checked al yr hoses for cracks ? As mentioned above - this system is a real bitch once it starts acting up...

Any chance to get me a good used A/C system from a scrap yard for a FORD TAUNUS ( I only would need the lines, condenser, heat exchanger - basically look for what you can get and I'll look for the rest myself )

Regards

Egal

sorry,

do u want the pictures of my car and a/c system or what?

I didin't understand?

would be helpful - and if possible the price of a good complete a/c unit to be installed in my Taunus in Germany - if you can arrange something along those lines.

Regards and a nice weekend

Egal

Zitat

Original von Egal
would be helpful - and if possible the price of a good complete a/c unit to be installed in my Taunus in Germany - if you can arrange something along those lines.

Regards and a nice weekend

Egal

Thanks, first of all, I'm a Turk and I live in Turkey. I have no camera but my brother has a digital camera, I may take it from him and take the photo of the a/c and the motor. About arranging parts and etc. for Ford Taunus, I can say that as you know after 1985, Ford Taunus is started to produce in Turkey by Otosan, therefore there are many parts of Ford Taunus in Turkey in everywhere. Also, there are many Taunus'es in Turkey. About a/c systems I don't know exactly so much about it. The problem is I live in a small city, and there are only two stores that only sell Ford Taunus spare parts and both of them do not have a/c system spare parts, but in other big cities especially in Istanbul, you can find every part of Ford Taunus you want in an acceptable price. The other cities are Bursa, Kocaeli, Ankara and etc.

If you want new or used parts I think I can help you. The prices are not high here in Turkey, but I think sending them to you would cost much even I do not know how much. Also, there are some internet web pages in Turkey about Ford Taunus spare part sale.

I'll send the pictures of my Taunus a/c system and motor in a few days.

Bye,

Serkan

How can I attach a picture here?

How can I attach a picture here?

Gerg,

I do have a friend of mine ( working for the same company I do ) living in Istanbul, and working in Gueluek - he can arrange transport 4 cheap.

The only problem is that he doesn't know much about cars - so I do need you to help me to get hold of the correct parts. If possible the a/c suystem should come off a V 6 donor car.

As I'm not in a hurry please have a good look around and let me know how much the parts are ( used or new ) and let me know how I can transfer the money to you.

Regards

Egal

As I remember you need the lines, condenser, heat exchanger. The lines are not so problem, I think it can be found very easily, but there's such a point that what kind of refrigerant you'll use. My a/c system is old and it's working with Freon 12, as you know it's forbidden in Europe, because of the environmental reasons. It's also forbidden in Turkey, but you can find it in Turkey, also it's cheap :) For example one month ago I refilled my a/c sytem with freon 12 at about 15 USD, it would be about 50 USD for R134a. Therefore my cooling lines are aluminium. Also my compressor is designed to be used with Freon 12.

But, if you want to use the newer refrigerant that do not cause the ozone layer damage, ex. "environmentally friendly" refrigerant, R-134a, you have to make a conversion. A special compressor(depends on if your compressor work with R-134a), special lines (not aluminium) generally plastic, new receiver-drier and etc....This is the point!! The used parts for Ford Taunus cars with a/c system will be 99 % to be used with Freon 12 in Turkey.(this is my opinion). If you decide to use a Freon 12 system, check for a supplier of freon-12 in your country and city, if you find, I think it'll be more expensive than R-134a, because the manufacturing of Freon 12 has stopped. So, check before deciding!

And I didn't understand what you mean by heat exchanger?

If you need a full used a/c system for ford taunus, I have to make a search in the junkyards. I think it'll be cheap. But think about what I said about the refrigerant above and decide!

By the way, the city I live in Turkey is Düzce, may be you've heard of it in news because of the big earthquake in 1999 in Turkey. This city is between Istanbul and Ankara, both have the same distance about 200 Kms. The most suitable parts (used or new) could easily be found in Istanbul and Ankara. Therefore, I have to go there, and it's possible when I can find time apart from my job. So, I cannot look for the parts immediately, but I usually go to my wife's city of birth, Adapazari (Sakarya), and I know there are usually used parts for most of the automobiles. For me, I usually cannot find some new spare parts in my city, then when I've gone to Adapazari, I can easily find new spare parts for my Taunus.

Also, there's a choice, that my brother is a mechanical engineer, and he knows most of the refrigerant mechanics in my city. One of the mechanics that I know from him, is a good technician, this man works for (home) refrigerator repair, but he has a good knowledge of car a/c system also. For example, last month, I refilled my system with the help of this technician. I think, this man can make an a/c system for any car in the manner of a new design. (he also works for factories).

So, if you tell me exactly what you need, I think I can help you. Especially, about the parts. :) Do not forget about the refrigerant!

Bye,

Serkan

you can buy conversion kits in the US of A for cheap - you got to drain the " old and bad " gas fm the system, you need to drain the compressor oil and replace it with a special - i.e. + expensive one. Might have to change the retaining rings on the rive shaft of the compressor and thats it - as I have plenty of time - please take your time and chase the newest parts and let me know how we can arrange payment....

If you have a chance pls send me the pics of yr a/c system and I'll have a look at it to see whether I can help U.

Regards

Egal

I'll send the pics to you, please give me your e-mail, because I cannot paste them here. My brother is out of city, he!ll be back on Saturday, then I'll take the camera from him and will take the photos. :)

Bye,

Serkan

Hey Egal,

The pictures are ready, would you give me your e-mail? I couldn't put the pics here, because I do not have a web page. If you have one and want to put them here also, I'd be appreciated. The zipped files take totally 4.1 MB :)

Bye,

Serkan