yotanothing

If vaccum advance isnt working, will it still have good low end but once you get it up in the gears not being advancing and runnin retarded quiet a bit and not have alot of power to get it up to speed???

TNRabbit

Is this just a continuation of your other thread??

yotanothing

yeah, just to ween out the other people that didnt see or wanna read the whole thread...

yotanothing

any other way to till if vacuum advance is workin on dizzy without a vacuum pump... does the engine have to be under load for the timing to advance? If i were to use timing light and check it at idle will it advance when you floor it without a load on motor????

84sr5yoty

First off, make sure that both diaphragms on the vacuum advance can are holding vacuum. The inner diaphragm (the one closest to the motor) is known to fail first. I simply remove the hose from the source (throttle body or carb, depending on the fuel source) on the opposite end of the vacuum advance can, and suck on it. Both diaphragms should hold perfect vacuum indefinitely. Do this for each vacuum line individually. You can remove the distributor cap and watch the vacuum advance plate move (and it should!!) while you're performing the vacuum tests.

westport toyota

my 22r make a pinning niose at 55 . super unleaded seems to helps a little bit but something is not right in there. I had the advance, vacum tested but it was fine. does anyone have the same problem?

yotanothing

i take it doesnt take much vacuum to move actuator arm inside of dizzy??? I think i tried to suck as hard as i could and it didnt budge...lol

Tool Pants

Do you have a timing light? If so rev it up and see if the timing advances. Do not have to drive the truck to see if the vacuum advance is working.

I have a vacuum pump. 2 in fact. I also have a 22R with carb that has the dual diaphragm. I can stick a piece of tubing on the advance side and suck hard enough with my mouth to make it advance - don't need the pump to make it advance.

yotanothing

which port is advance.....Closest to Valve cover or the one closest to radiator? My manual does say that, But either way i sucked on both hard as i could and didnt move one bit....Trying a vacuum pump today and if nothing gonna go find a dizzy

Tool Pants

Just for you and to keep it simple.

Remove the cap from the dis. Get a spare piece of tubing that fits the port near the radiator. One end of the tube on the port and the other end in your mouth. Suck on the tubing and see if the plate inside the dis moves counter clockwise. I can move it with my mouth on my 1988 22R with carb. California emissions.

If you can't move the plate then you do not suck hard enough. Or the plate is stuck. Or something else is wrong that I cannot think out at the moment. Note that there is a clip that connects the diaphragm arm to the plate.

I was going to get my spare piece of tubing and take pictures of my mouth, but I do not have 3 hands. So I used my vac pump. I made 2 small white dots on the plate that moves. There is a larger white dot to the right on the housing. These dots are the reference point for the pics so that you can see how the plate moves when there is a vacuum.

No vac in this picture. Note the location of the 3 white dots.



Here I have pulled a vac with the pump. By looking at the dots you can see that the plate has rotated a few degrees counter clockwise.

84sr5yoty

Both diaphragms cause advancement. The diaphragm closest to the valve cover (direct manifold vacuum) advances more than the other (ported vacuum). Basically, it senses both ported and direct manifold vacuum and adjusts the timing using both accordingly.

In muscle car forums you'll see long, heated debates about using either ported or manifold vacuum (older American cars didn't have dual diaphragm setups like Toyota). Both have their advantages depending on how the engine is setup (ie modifications) and what RPM it will be running at. Toyota was ahead of the game and used both, resulting in super accurate advancement of timing in ALL conditions.

Tool Pants

I learned something new today about the Toyota I have owned for 18 years. I have always though the port next to the valve cover was to retard the ignition, and the port next to the radiator was to advance the ignition. I once had a car with a dual diaphragm and that is how it worked on the car.

Not so on the Toyota. When I pulled a vac on the port next to the valve cover the plate rotated counter clockwise. I was expecting it to move clockwise to retard the ignition.

TalibanToy

So, if the "sub-diaphragm" won't hold a vacuum, then it is shot? I looked at a junkyard unit and it, like mine, didn't hold a vacuum. Now I have the hose with full vacuum connected to the port closest to the radiator. It pulls the advance to 12 degrees like its supposed to. So why replace the vacuum unit for $130 when I paid $500 for the truck?

84sr5yoty

If either port doesn't hold vacuum, then the vacuum advance can is shot.

If you give me the year, motor, transmission, fuel type (EFI or Carb) of your truck, I can look up the part # on my microfiche slides. From there, you can buy a genuine Toyota one from 1sttoyotaparts or from Strapp32 (he is a member here) for much cheaper than the dealer (even cheaper than aftermarket parts).

stock87

Alright, first of all, the way the vacuum advance works on a 22R, it only affects it at idle, on deceleration, or if you have a HAC.

At idle, it advances the timing to help with emissions, and with the HAC, it advances it over 4500 feet or so and leans out the mixture to help with drivability. Pretty sure it also advances it when engine braking.

The cheapest place to get a new one is http://www.1sttoyotaparts.com, even cheaper than the aftermarket ones. 19220-35140

Really the only thing that was different on my truck when it went out is it wouldn't fast idle when cold.

jjohnn11

two questions.

1. Where is the cheapest place to get a vacuum advance diaphragm for a 1983 22R carbureted Celica ST engine? (same as pickup I believe)

2. I have seen some kind of an electronic gadget that supposedly replaces the conventional distributor that costs about $300. Can not remember exactly what it is called. Is this type of replacement distributor capable of passing California smog laws or is it even legal?