1981 tercel keeps stalling

[4doorVIP]

Hey everyone I'm pulling my hair out on this one.
My fiances newly purchased 1981 Tercel automatic 3A-C no longer wants to idle,

here is the run down so far:

1. The car was would never start first or second time from cold, unless the block heater was plugged in.
It would also randomly stall at traffic lights, and the battery/ebrake light would flicker on/off.
-I changed the oil (new 5w30), put in new spark plugs, new cap and rotor. So the car now starts up first time after 2 pumps of the gas.

2. Now that the car starts first time, it no longer keeps an idle. Now the unfortunate thing is, this car has no tachometer so I can only adjust idle speed via ear, I made it sound as close to my wagon as possible... Even if I set my idle to what sounds like 1500rpm or so, it will still stall out.

The trouble is the car will start up just fine, but if I put it in Park or Reverse she wants to stall. If I keep it in Park for 30 seconds or so it will hesitate then stall completely.
So far I've replaced a couple vacuum hoses, and also replaced the fuel hose inside the engine bay that runs beneath the air filter (it had a gash but did not leak fuel).

I'm really not to sure where to go from here, troubleshooting is not really my forte. I've cleaned the contact posts on the battery, terminals, and made sure they are snug.
Next thing I did was to hook up a voltmeter, the battery has 12.9V with the car shut off. After running the car it jumps to 13.9, then to 13.7 with my headlights on and the fan at full blast. Would this not indicate the charging system is okay?

Could this possible be a faulty EGR valve? I was going to try cutting a plate out tomorrow, capping the egr valve, and then running it that way - what do you think?

Any suggestions will be met with a warm welcome

-Scott

[dlb]

no, not likely EGR. it functions when the engine is warm and between moderate to high throttle so it's not engaged at idle. when you say the battery/brake light flickered, was the car also idling poorly at those times? if so, i'd guess it was just on the verge of stalling out. the other info you give suggests your battery and alternator are fine.

you said the car starts fine now but if you put it in "park or reverse"—did you mean if you put it in drive or reverse? or are you starting in neutral? there are two things i would check first though. first is the transmission throttle linkage. it's the big clumsy linkage that runs from the lower passenger side of the trans up to the throttle on the carb. instructions for checking/adjusting it are in the FSM on page 373/AT-5. basically, when you clean all the crud away from the bottom of the trans you should see a mark on the trans and an indicator line on the trans throttle linkage. the indicator line should align with the mark. if they don't, you need to make sure the linkage is straight and not bent all to hell, and then adjust the turnbuckle and locking nut until the marks align. i just did this on mine and found the turnbuckle was seized so i popped the linkage off and worked on it on the bench. it's a ball joint on either end that can be snapped on or off. this linkage controls how much throttle the trans gives the engine when it is put into various gears. mine was way out and the revs were super high at idle, super low in gear, so it really slammed into gear and would sometimes stall if it was cold. after adjusting it, there's only like 50-100 rpm change when i put it in gear now, and much smoother.

the other thing to check is the TP, or throttle positioner. it's on page 103/EC-15 of the FSM. it controls how quickly the throttle snaps shut when you left off the gas. too quickly causes high emissions and can stall the engine if your rpm are too low to start with, and too slow is annoying and could cause dieseling. i'm not convinced this is your problem but i adjust this on mine after doing the trans throttle linkage and the two made a world of difference for me.

of course, go through all the basic vacuum stuff as well and confirm that all the hoses are correctly routed, actually hooked up, and suck on all the diaphragms (choke breaker, choke opener, vac advance, etc) to make sure they hold vacuum. diaphragms that don't are vacuum leaks. there should be a vacuum diagram on the underside of the hood that you can use for the routing.

good luck, scott.

*edit* i just reread the FSM section on the trans throttle linkage and i wanted to add to what i already said on it: the marks must align WHEN THE GAS PEDAL IS PUSHED TO THE FLOOR. i totally forgot about that part but it's a crucial detail.

[TURTCEL]

no, not likely EGR. it functions when the engine is warm and between moderate to high throttle so it's not engaged at idle.

of course, go through all the basic vacuum stuff as well and confirm that all the hoses are correctly routed, actually hooked up, and suck on all the diaphragms (choke breaker, choke opener, vac advance, etc) to make sure they hold vacuum. diaphragms that don't are vacuum leaks. there should be a vacuum diagram on the underside of the hood that you can use for the routing.

.

I would still check the EGR valve to see if it is faulty, I had a similar situation and it surprisingly it turned out to be a bad EGR valve. In my case the car would run like s@#t when I had the EGR valve hooked up but when I pulled and plugged the EGR valve hose the symptoms went away. I would have a rough idles and it would die when I would come uo to a stop. It would also buck and stutter with the EGR hooked up. Mine would even do it at idle, weird. At least try it...very easy to at least eliminate.

The TP diaphram is also a good suggestion to check and can be adjusted easily if necessary and as long as the diaphram is ok.

I would also suggest just replacing every vacuum line on the engine since they are probably all old. Cheap job to do...make sure to over buy on the hose though. I like to cut my pieces just a little longer than the factory lenghts so that they fit on the hard plastic connecting lines further and won't risk popping off. But most importantly, check to make sure they are all correct...never trust a previous owner to do things right. Just having one major line be wrong can cause serious runnability issues.

Another thing to check is the carburetor mounting gaskets for vacuum leaks. There are 3 gaskets used in mounting your carb. I also had a leak at this point on my car...make sure to evenly tighten carb back down, uneven tightening can cause these gaskets to leak. Make sure to check for vacuum leaks at the throttle shaft, mine was so bad that it did exactly what yours did.

You can sometimes adjust the fuel mixture a little richer to compensate for a throttle shaft leak. You might have to drill the plug out of your carb if it has never been done in order to access the mixture screw. Remember that your idle speed will change with mixture adjustment so you may have to adjust idle screw too. Make sure timing is correct and engine is warm before adjusting anything.

Hope this helps.

Peace

[Petros]

It sounds like a vac leak. check for vac leaks with carb cleaner spray, spray it around various places while it is running and when the engine speed changes you found the leak location.

distributor vac advance, the EGR, the mixture control and the high altitudes compensator (HAC), and a leaky TVSV, can all also act like a vac leak. You may not have a HAC, early cars did not have them.

All advise above is good, also I have seen a weak/poor coil/igniter in the distributor act this way too, too weak for reliable low speed spark, but seems to run okay at higher rpm.

You can find the problem, just take it one step at a time checking each of the items listed above. Good luck.

[4doorVIP]

hey guys, I picked up a 10ft spool of vacuum hose and am in the middle of replacing it all.

all the lines looked like they were hooked up properly, I ended up breaking a VTV(?)

these brittle nipples broke off with the hose..hopefully these are not hard to find.blergggggh


heres a shot of the vac diagram, seems more basic than my 87 terc

[Petros]

that is a one way check valve I believe. You can still the the car just cap off both ends of the vac lines that it runs to. Those are still available, and you can find them in a wrecking yard, most models of Toyota from 1980-88 or so use them. The plastic gets brittle when it ages so this kind of thing does happen occasionally.

[4doorVIP]

So far what I've replaced.
new spark plugs
new cap & rotor
new oil change
new vacuum lines

the only thing I haven't tried yet are no spark plug wires, those are on order tomorrow

Here is a short video I took, you can here the motor misfire
http://www.youtube.com/watch?v=aRUxfCkX ... r_embedded

[dlb]

did you check the trans throttle linkage like i mentioned? i just watched your video and no longer think that's it but it will affect how the car idles in all gears, and how it shifts between them.

looking at your vacuum diagram, i would check the AAP, choke breaker, TP, and vac advance unit. all are possible sources of vac or fuel leaks. if the AAP is leaking, when the engine is cold fuel will get sucked through that hose to the TVSV and then to the gas filter and finally dumped in the intake manifold. that would certainly cause shitty running. it would also leak a bit once warmed up, too. check all those things though. old cars can have so many worn out goofy little parts so dig deep, bud.

[4doorVIP]

hey guys, its been a while. Im still trying to figure out this 81
I took dlb's advice and checked the trans throttle linkage after some cleaning (haha) - it was way off mark. I corrected it, and the car only drops a few revs when shifting into D or R. This car does not have a tach but it sounds like 20-100rpm max. Before it would drop what sounded to be 200-300rpms.

With that sorted, the car still dies in the following scenarios:
I start the car in P, keep it in P, it sounds like it is idling around 1100ish, but I can slowly hear the revs die off. This is without me even touching anything. It slowly dwindles down after a few minutes then dies.

I start the car, put it in D or R. The motor sounds nice and smooth, but as soon as I give it gas and let go the car instantly dies. It is as if it is not getting enough oxygen or is hitting fuel cut??

As far as timing, I do not have a timing light so I'm doing it by my senses.

I took a photo of distrb rotor with crank pulley set to 0:

[Petros]

sounds like the choke may not be opening. have you took the air filter assembly off when it is cold, and than start it and watch the choke plate at the top of the carb inlet? It should open as it warms, if it does not it will die off unless you keep it reved so the linkage opens the choke plate.

hard to tell in the pic, but the distributor looks about right. Close enough that is not likely why it is dying (unless you have a marginal coil that stops working after it gets hot). Check the spark by pulling one spark plug wire after it stall out, and hold it next to metal ground (the engine block), and have someone crank it to see if you are getting a strong spark. You should get a strong bluish spark that goes "snap, snap, snap!" If its weak, yellowish and intermittent, likely the coil is bad (or one of the internal distributor parts). Many parts stores have the ability to test a coil on the bench, find one and take it in, and the distributor too. Once you have this issues sorted you can set the spark timing by "ear", advance the timing until you get ping on hard acceleration, than back it off until you get no ping. You want the most advance without ping, that will give you the best economy.

Good luck

[dlb]

scott, i have a timing light. let me know if you're coming up here and you can use it anytime.

[Mark]

A quick check for internal vacuum leaks that are not visible by checking the hoses can be done pretty easily. With my wagon I had a large vacuum leak in the auxiliary acceleration pump (AAP) diaphragm and in my EGR vacuum modulator valve (EGR-VM). Looking at the vacuum diagram in the post above, disconnect and plug hose "N" from the TVSV. If the idle smooths out, there is probably a vacuum leak in the AAP. To check for an EGR diaphragm leak, disconnect and plug line "P" from the EGR-VM. -Again see if the idle quality changes.
You mentioned that when you start it up it idles at a certain speed and then gradually slows down. This would probably be the automatic choke opening, which is normal. Did you or anyone that you know of tinker with the idle speed screw on the carb? Maybe it's set too low. I think my 2ng gen auto wagon is supposed to be at about 800 rpm. Keep in mind, this is the speed when the engine is warm and the transmission is in park. When the engine is cold and the choke is closed, it should idle much faster.

One last thing, which is probably not related to your problem: You said you put 5W-30 oil in it? The lowest-viscosity oil recommended in the owners manual is 10W-30. 5W-30 may not have enough "cushioning" for the larger clearances in our older bearings. At least this is my impression. Hopefully some others here would be able to confirm or mock me on this. It would be nice if we could use that thinner oil for better economy.

[4doorVIP]

sounds like the choke may not be opening. have you took the air filter assembly off when it is cold, and than start it and watch the choke plate at the top of the carb inlet? It should open as it warms, if it does not it will die off unless you keep it reved so the linkage opens the choke plate.

hard to tell in the pic, but the distributor looks about right. Close enough that is not likely why it is dying (unless you have a marginal coil that stops working after it gets hot). Check the spark by pulling one spark plug wire after it stall out, and hold it next to metal ground (the engine block), and have someone crank it to see if you are getting a strong spark. You should get a strong bluish spark that goes "snap, snap, snap!" If its weak, yellowish and intermittent, likely the coil is bad (or one of the internal distributor parts). Many parts stores have the ability to test a coil on the bench, find one and take it in, and the distributor too. Once you have this issues sorted you can set the spark timing by "ear", advance the timing until you get ping on hard acceleration, than back it off until you get no ping. You want the most advance without ping, that will give you the best economy.

Good luck

Thanks Petros, yes it looks as though the choke plate is opening. I took the air intake off, and the choke plate opens all the way, then the car stalls out.
If I grab the choke plate with my hand, and close it almost shut, the car will start to idle and will not die. Hopefully this makes sense, it almost sounds like the opposite of how it should work?


Here is a video of the car running while in Park, nobody touching the trottle - you can see the choke plate fully open, and the car stall out:
http://www.youtube.com/watch?v=ib4DEtkU_9o

[4doorVIP]

scott, i have a timing light. let me know if you're coming up here and you can use it anytime.

hey man, I will most likely take you up on that offer some "time" - not trying to be punny
it would be cool if you could show me how to use one, I'm pretty green with the concept still

[4doorVIP]

A quick check for internal vacuum leaks that are not visible by checking the hoses can be done pretty easily. With my wagon I had a large vacuum leak in the auxiliary acceleration pump (AAP) diaphragm and in my EGR vacuum modulator valve (EGR-VM). Looking at the vacuum diagram in the post above, disconnect and plug hose "N" from the TVSV. If the idle smooths out, there is probably a vacuum leak in the AAP. To check for an EGR diaphragm leak, disconnect and plug line "P" from the EGR-VM. -Again see if the idle quality changes.
You mentioned that when you start it up it idles at a certain speed and then gradually slows down. This would probably be the automatic choke opening, which is normal. Did you or anyone that you know of tinker with the idle speed screw on the carb? Maybe it's set too low. I think my 2ng gen auto wagon is supposed to be at about 800 rpm. Keep in mind, this is the speed when the engine is warm and the transmission is in park. When the engine is cold and the choke is closed, it should idle much faster.

One last thing, which is probably not related to your problem: You said you put 5W-30 oil in it? The lowest-viscosity oil recommended in the owners manual is 10W-30. 5W-30 may not have enough "cushioning" for the larger clearances in our older bearings. At least this is my impression. Hopefully some others here would be able to confirm or mock me on this. It would be nice if we could use that thinner oil for better economy.

hey Mark
thank you.
This car has all EGR related stuff deleted and plugged.
I disconnected the line on TSVS N, then capped the TSVS nipple.
With the line still attached to AAP it did not change revs either with the line capped or not

yes idle speed screw and the lot have all been tinkered with during my frustrations with this car unfortunately. Is there a way to put them all to default settings? lol ugh