Timing

[celtglen]

I have a question to everyone; when your timing is set, is your distributor pushed all the way toward the fire-wall?
The only way I can get to 13 degrees is to do this. The timing belt and tensioner and dizzy are new. Having the dizzy pushed all the way to one side just doesn't seem right.

I got the car started AND running, albeit not too well--running that is.

Pulled the spark plugs and found them burnt to black--no wonder the poor thing wouldn't start. I will post pics tomorrow if anyone wants to see them.

I put in used-but-still functional Bosch 2+s I took out a while back. Car started, I reset the idles and even the TP is adjusting! She revs but is sluggish. I am pulling the exchanged plugs tomorrow to see if they too are BLACK. I don't expect them to BE black because the timing is set and idle speeds good. I will also test the AAP, the choke, and the plug wires and the cap. The only thing I can think of other than the electric signal from the dizzy is way WRONG. The dizzy goes back to RockAuto as soon as I can get my old dizzy back in the car. The ONLY reason I replaced the dizzy is that the vac advance went out on her AND that the dizzy is over 25 years old. Car was running fine, except for runs over the Cascades (no advance). I wish I had simply bought the advance and been done with it. Zeesh..you live you learn.

The timing is now set with the idle at roughly 900 RPMs. Again discovered that the vac advance on the dizzy I bought is non functional, so I set the timing to 10-13degrees BTDC WITH the vac advance hoses plugged in.

Is that right or should I plug that line?

[Petros]

Not sure I understand the condition of the car; does the vac advance work now or not?

You should have 10 deg timing with the vac lines to the vac advance pulled and plugged at 800 rpms. With the timing set like that, and vac lines installed and the vac advance functioning, it will show something 13-17 deg BTDC. Also, rev the throttle with the vac lines removed and plugged, and watch the timing mark, it should advance on the mechanical advance alone. If you do not get advance with the mechanical advance or the vac advance than it has to be replaced.

IF neither work you can likely run it by setting the idle at about 1200-1300 rpms and set the timing to 16 deg, but I would not run it long that way. But if the mechanical advance does not work I would fix is fairly soon. I would take the distributor apart and clean and lube all the mechanical advance parts, they can get try and rusty and stick (fairly easy fix).

It will run fine without the vac advance working, it only affects the economy of your part throttle cruise at hwy speeds a little. That is also an easy fix with a replacement vac advance assembly.

[celtglen]

"...it should advance on the mechanical advance alone"

I don't know what this means.

The vac advance does NOT advance.

I have three vac lines on my vac advance..are you saying to plug all 3 then reduce the idle from 900 to 800 RPM ?

[dlb]

on some of my tercs, the dizzy has been turned quite far clockwise (toward the firewall). it depends which teeth of the cam gear it's meshed with. i don't think that's your problem--if the timing is set and it's consistent, that should be good.

you said that the vac advance cans on the new dizzy don't work. you mean you sucked on them and they did not hold vacuum? if that's the case, you should not leave the vac lines connected to the vac advance cans because the lines will suck air, which means they are big vacuum leaks. if the cans do not hold vacuum, disconnect the lines and block them.

have you tried pulling each spark plug wire off while the car is idling to make sure that each one is firing properly? a compression test might be a good idea too. instructions to do one are in questions #1 in the FAQ:

https://tercel4wd.com/forums/viewtopic.php?f=2&t=7442

[dlb]

"...it should advance on the mechanical advance alone"

I don't know what this means.

The vac advance does NOT advance.

I have three vac lines on my vac advance..are you saying to plug all 3 then reduce the idle from 900 to 800 RPM ?

there are two types of advance in the dizzy. the vac advance operates off of ported and manifold vac via the vac cans, and mechanical advance is a system of spring-loaded weights in the dizzy that advance the timing in relation to engine RPM. to check the mechanical advance, you can do the test you already did: try turning the rotor counter clockwise and confirm that it has some spring-loaded play in it. additionally, another test is to disconnect and plug the vac advance and put a timing light on the crank, and watch the timing mark. at idle it should be at 5* or 10* (or whatever you've set it to) and as you rev up to, say, 3000 RPM the timing should advance to 18* or something like that. there may be specs on that in the FSM but i'm not sure. i'd say if it advances noticeably at 3000 RPM, the mechanical advance is fine. be sure to reconnect the vac advance after doing this test.

if neither of the ports on the vac advance cans holds vacuum, then yes, you must disconnect the vac lines and plug them all off. otherwise it's sucking a lot of air through those broken diaphragms, and that's bad. you can run without vac advance, it's not a big deal. i've found the engine doesn't run as smoothly without it but it was fine. many forum members have and do run without it. i think that going long term without it is a bad idea because without it advancing the timing at idle and hwy speeds, you get higher exhaust temps which will wear out the exhaust valves quicker but it's fine for weeks or even months.

[celtglen]

Thanks DLB,

[Petros]

I did not mean to confuse you, I guess you still have not got all the terminology down. What DLB wrote is exactly correct. What you did not know can be summarized this way:

two types of spark advance, mechanical advance and the vacuum advance (both do very different functions):

1) mechanical advance that has weights in the distributor that simply advance the spark timing as the engine rpm increases (all loads and all conditions). The faster the engine runs, the earlier the spark has to ignite the fuel/air mixture since the fuel/air mixture burns the same speed at all rpms (so it has to be ignited earlier in the cycle at higher rpms). The optimal timing will result in more power and better efficiency. The early cars did not have this, but had a lever on the dash or steering wheel that the driver would advance as he accelerated the engine speed.

2) the vacuum advance that adjust the timing based on the amount of load that is on the engine, the lower the loading the more the spark can be advanced without having ping or preignition. It is operated off manifold vacuum, the higher the vacuum the more the advance. When you stomp on the pedal (increase the load on the engine) the vacuum drops and reduces the timing to lower the risk of ping. the vacuum advance is also used to adjust the timing for high altitude (above 3900 ft) if your car has the High Altitude Compensator (HAC in the vac diagram), and to retard the timing during certain conditions to reduced NOx emissions. In most driving conditions if the vacuum advance is not working it will not affect drivability or starting, but might have a slight effect on cruise economy.

So, it is not such a bid deal if the vac advance is not working, but it does help your economy to have it in working condition. And the mechanical advace is important to have working all the time, but you could get by if it is stuck by advancing the timing a bit and letting the idle speed up until you can fix it. I would not run too long without the mechanical advance working.

[celtglen]

OK, thanks for the explanations!

The mechanical advance moves just fine, and I set that as close to 18 degrees (@high rev but not 3k) as I feel comfortable with.

I can no longer work on the car at my apartment the manager said to stop working on my car on his property.

So I have to get her started and go to a field and do the testing and such.

Only ONE of the THREE vac lines is not working, the vac advance to HAC. So as far as plugging that port I assume I plug the port on both the can and on the line that connects TO the can..I mean this may seem like a DUH to you guys, but I am officially now out of money so I cannot hire anyone to fix her any more.

BTW Thanks for your patience and your help, I really appreciate it.

[dlb]

no problem CG, glad to help. and no need to worry about "duh" moments. if you're unfamiliar with a system as odd as these carb vac ones, there are plenty of valid questions to ask. besides, everyone has lots of duh moments.

you are partially correct about blocking faulty vac items. the HAC line should be plugged, otherwise it will suck air. you can simply jam a screw or bolt in the end of the vac line but i prefer to use rubber plug that go directly on the ports. you can grab these at any auto store for a few bucks. the ports on the vac cans don't need to be plugged though because they don't suck air. they only house the diaphragms which get sucked on and move the vac advance mechanism.

but something doesn't make sense here--the HAC and manifold vacuum port on the vac cans share the uppermost diaphragm. this is confirmed on page 128/EC-40 of the FSM in the remark at the bottom of the page. so if your HAC port is not holding vacuum, then your manifold vac port shouldn't either. take another look/suck on those and let us know what you find.

[celtglen]

Hi again,

DLB..."the HAC and manifold vacuum port on the vac cans share the uppermost diaphragm." Yeah it does on the 83 and maybe on y'alls 4WD..not on mine. I have THREE ports on the can--as I always have... 84 2WD Auto tranny. There is a difference between the 83 and 84's vac cans according to the Toyo service manuals.

I was thinking...since the other two ports on the vac can are working...I could split the suction on one for the HAC as well. I also have an 83 service manual..and that one shows TWO ports on the can with the HAC sharing a port by way of a junction.

Monday is another day .. I am dead tired and broke.

Thanks again everyone have a nice weekend..

[dlb]

ahhhh, i hadn't thought of that. can you take a picture of your vac cans for us? you've piqued my curiosity now.

yes, i think you could probably put a 'T' in the uppermost diaphragm line and run both the manifold vac and HAC off of it. i've read about a "brass restrictive device" on the HAC port though, which sounds like it moderates the amount of vac that can be applied to the diaphragm. if that's the case, you would also need to put something like this $1 item between the HAC and the T-junction:

http://ca-en.hagen.com/Aquatic/Aeration ... ries/A1172

all this aside though, the symptoms you've described don't sound like a single little vacuum leak. initially, you can just try disconnecting and plugging the HAC, checking the timing again (since it may have been set when you had a vac leak which would raise the RPM and thus alter the mechanical advance) and resetting it as necessary, and see how the car drives then.

i know tracking down these gremlins can be a pain. i just spent 3 weeks looking for one stupid adapter to check the oil pressure on my all trac. i had to drive the VW during that time, and i was not a happy camper. just be diligent and you will find it, and then we will all be wiser for it--i love how each of our experiences helps the rest of the forum community.

[celtglen]

Hello all,

After about 5 hours work, she is running again--not perfectly as she did before, but hope is on the horizon

dlb, the third vac line on the can is indeed dead. I tried to T patch in to the second one next to it (NOT the bottom port) and nothing doing. So I plugged the port for the dead (Vac advance) line.

Petros; The mechanical timing is fine, after plugging the vac advance I set the idle speed to about 1400 RPMs which advanced the timing to 13 BTDC.

I also replaced the cap/rotor/wires and plugs, replaced the rad cap and cleaned out a LOT of muck out of the hose to the overflow tank AND the line that goes inside the OV tank..it too was completely blocked with rad stop leak that the mechanic put in--the WHOLE DAMNED bottle ...not paying attention that the rad carries just a gallon of fluid and the cooling system; precious more.

SO the overheating is less than before but still present...cooling fan and switches are all functional so cooling her off is not an issue. I will have to flush and drain the cooling system when I find a place to do that myself

[celtglen]

RockAuto is very happy to replace the dizzy I just have to send them the tracking # for the return or buy a new one (shipped free this time) and once they get the tracking # for the returned dizzy they will refund my bank card.

Not surprising for RA-- they are fine folks.

This is problematic for me; I could easily pull and ship the returning dizzy BUT I am really unable to hand crank the engine and put in the new dizzy...the $$ I had was spent last week with a shade tree mechanic who "dun-me-wrong".250 down the bleedin drain for him..the part 170.

Any money I might be able to find--like 50 bucks--to put in the new dizzy is going to HAVE to be a mechanic who will do-it-by-the-book this time. That shade tree mechanic refused to use it..and got me to where I am today.

I have injuries which limit my ability to do the physical work on the car I use to. Does anyone out there know a mobile mechanic that they trust? To put IN the new dizzy should take all of 30 mins. I am just south of Seattle.
thanks

PS DLB..I am going to shoot some pics for the board in a day or two..too tired today

[Petros]

I have no plans to go that far south in the near future, but I would be happy to install it for you if I did. List member Synth lives in shoreline, much closer than me, he could help you out I am sure. There are also several Tacoma list members not far from you, perhaps one of them might be willing to help you.

Is the car drivable, or does someone have to come to you?

[celtglen]

I have no plans to go that far south in the near future, but I would be happy to install it for you if I did. List member Synth lives in shoreline, much closer than me, he could help you out I am sure. There are also several Tacoma list members not far from you, perhaps one of them might be willing to help you.

Is the car drivable, or does someone have to come to you?

She IS drivable but I have to return the one in her to RockAuto so they can send me a replacement. I have AAA and 2 more, 100 mile tows left until I renew in March. I would be happy to come with her TO you on the AAA tow.

It might take a week to get the new dizzy here..what days and times would be convenient?

Thanks