Its me again, Margret---fixin this carb

[badmechanic]

Hellos and Salutations!

From your favorite bad mechanic, a new and lustrous ordeal has commenced!

Ok so if you remember my poor lil' toyota, its an 83 6 spd, *replaced engine*

Right on! ok cool so works pretty well, but started smoking and has foul exhaust smell. I have looked and looked for a vacuum diagram that fits me but none do exactly. When i put the used engine, the vaccums weren't all hooked up right, i got them as close as i could with the diagrams, but like i said they don't seem to match.
So decided to tinker hehe around and see if i can find the problem. (rebuilt carb btw) i did a compression check, head gasket and rings are good. it dosen't smoke at idle, or for the most part when i drive it, but mostly when i'm driving and off the gas for say a sharp turn w/o stopping, when i hit the gas a small cloud of smoke comes out. kinda bluishwhite smoke with unburnt gas smell.

this might be important: i have gone around using the vacuum switches that control the ac, healight, fan, and what ever other switches there are that compensate for draw, some of the switches don't work so i said screw them all.

anyway i was tinkering with it today, and noticed that a check valve was in backwards. OMG i switched it around and lots of smoke. lots and lots and lots. i've looked in the forum as much as my time will allow me, but i just dont' know bout this.

also lots of labor knocking through out whole rpm band.
vac. advance dosen't work either, bleeds air through.

lets see what else might help, if you need pictures to see the cluster (bad word here) please let me know. yeah

thx

[takza]

My mother once had a 76 Corolla that I decided to move some vac lines around on...big mistake...got worse and worse...she had a mechanic straighten it out.

Main thing would be to get the vac advance working right and to set the ignit timing right. Shouldn't drive it if it's knocking a lot.

Might focus on the PCV system...be sure it's working right.

If you left all the '83 vac stuff under there...then focus on whether Fed or California...then go about setting it right?

Might try Typhrus' simpler vac setup?

[ARCHINSTL]

Check in our Repair Guides section - there are color-coded diagrams for Federal cars - at least for '86, which should cover pretty much most, if not all, of the Federal wagons.
Also go to http://www.autozone.com; it has schematics for all of our cars, of whichever emission persuasion, including the most Northern Part of N. America.
Tom M.

[badmechanic]

I've gotten as far as the vacuum diagrams go, yesterday when i made the change, part of it was looping 2 vacs to skip a switch for?? either way none of the vac switches are hooked up on the car, so i believe even the computer if it has one is out of the equasion. as for vac diagram, like i said, none of the diagrams fit, mine has the 2 ports on the vacuum advance, but it dosen't work. the vacuum diagrams are different enough that if i hook it up like another one it dosen't run but if i hook it up like it is(which took hours) it runs fine. strange part is i hooked it back up just like it was, and now its smoking

the biggest change i made was a check valve was facing the wrong direction, when i changed it, smoke started bellowing out the tailpipe, and the exhaust leaks i had(neat way to find exhaust leaks). i'm checkin out the autozone place hoping they have mine.

i think i need to know how to pretty much do what a webber does, take out all the junk i don't need and keep as few as possible important things. Inspection not a problem here. but like i said gas mileage is in the crapper right now.

as i stated earlier, the engine i put in this thing, not sure what year or type of terc it came from, so i'm not even sure if the switches are exactly the right ones for that engine/carb setup.

i wanna go webber as we all do, but you know.

oh yeah! one more thing: the tube that comes from the exhaust with the reed valve in it? not hooked up. and the tube running from exhaust manifold that i believe runs to filter housing? jb weild shut. is that bad?

[Petros]

You need to find the cause of the problem before changing anything else, including changing carb, or you may not solve the problem with a lot of trouble and expence.

The vacuum advance on the distributor will not affect the way it runs. When it is working correctly it advances the timing when in a part throttle (low load) cruise to improve the fuel economy. But the emission control sensor cuts it out until the engine gets hot (retarded timing makes the exhaust hot, causing burned valves). That is what the thermal valve on the engine out let (with all the vac lines coming out of it) does. If the vac advance does not work you simply lose this feature, but you will not notice when you drive it. It will not affect peak power or make the exhaust smoke.

If it sucks air you should block off the vac line. If you replace the vac advance (recommended for economy), you might consider blocking off the other lines that only serve to retard the timing for emission controls.

The tube from the catalytic converter that goes to the reed-valve chamber should not affect the way it runs either. The idea with it is the natural pulses of the exhaust will pull in fresh air (through the reed valve). This allows the extra O2 to break down the emissions in the cat. You can remove it, but it increase the emissions and does not affect the way it runs, I am inclined to leave it as long as no exhaust is leaking out of it.

The tube from the exhaust manifold that goes through the EGR valve and then into the intake manifold (right under the carb) bleeds exhaust gas into the intake. It reduces combustion temperatures and reduces some of the emissions by mixing inert exhaust gas with the intake air/fuel mixture. The problem is it reduces fuel economy and peak power out put. You should not notice anything bad if this tube is blocked (except perhaps some engine ping on hot days at full throttle, if so switch to mid-grade or premium fuel). I would leave this line blocked, it will not affect the exhaust smoke and these cars are underpowered as it is, so you can use all of the extra power you can get.

As far as the check valve causing smoke when you reverse it, I do not know what could cause that. Usually if you get one reversed (which I have done before) it just runs badly. You might check if you have any vacuum leaks and block them off.

You should also be getting better fuel economy, it might be running too rich (too much fuel) which could also cause black exhaust smoke and the bad economy. A vacuum leak might cause that, or improper ignition timing. I would set the ignition timing at about 10 deg BTDC (not the 5 deg per the manual).

There are several electric solenoids on the carb (that are vacuum actuated) that cut off the fuel when you down shift and during certain other driving conditions. These reduce emissions but should not affect the way the car runs (and likely help the economy slightly). If they are malfunctioning they may cause bad economy and smoking exhaust. There is a manual procedure for testing these. But it might be simply a vacuum leak in the actuating lines causing them to malfunction. If you remove all of the vac lines you will loose this feature, which is not a bad feature and will not affect power or economy to remove it. So I would make sure this is working properly and simply leave them and their vac lines in place.

You might also check to see if your PVC valve is clean and working properly (clean it with carb cleaner spray), or simply replace it (they are about $5). If it is stuck it might cause excess oil consumption and bluish smoke in the exhaust. But it will not likely cause it run badly (and less it is really bad).

Most important is to make sure all of the vac ports are either properly connected or blocked off, and all of the hoses are connected properly. The vac lines can also crack and leak. Use a can of carb cleaner to find the leak, with the engine running and spray it at various places around the cab and intake manifold. If the engine speed changes, you just sprayed it at the place where the leak is located. If you have a leak, find it and fix it. Then follow the procedures in the manual to test all of the emission control equipment.

You should know that most of the emission control equipment if not working properly does not affect how it drives that much. So even if you find something not working you can usually block it off or by-pass it without any ill effect.

Good luck,

Peter

[badmechanic]

wow thanks peter, that must have taken quite some time to write up, so thank you for that.

i had a dream lastnight. was strange but to the point, the dream was about a bad valve guide.

i'd still get good compression with a bad guide right?
and smoke? possibly gas smellin due to the extra oil in the combustion chamber?

i dunno, but man i really believe a webber and/or 4-ac might be better idea for me. probably a combination of both.

we'll see, but about the vac leaks, all new lines no leaks, rebuild carb(by yours truly)

something i noticed. i believe i have a feedback carb, when i was looking at the vac diagrams, and the carb the other day i noticed i had a vac line running from the top of the carb, above the butterflys, and its running to the lower passenger side of the carb where there are 3 vac ports, one is on top of the jet needle and then there are 2 to the left of that one.

ok so my port above the butterfly connected to the farthest left port from the location above. does this cause a lean condition? that could cause the fuel not to burn completely and inconsistently. smoke? fumes?

if you need a picture i can modify one of the vac diagrams you have on this site to give you an idea of what i have done hehehe

[takza]

One of those ports is the R port that goes to the vac modulator for the EGR...if you have the EGR (if it works) hooked up to one of the full vac ports that might explain things?

The R port only activates above idle.

Since you rebuilt the carb and redid the vac lines...I'd have to assume you've got something routed wrong.

I have an '83 and might be able to scan the vac diagrams from a Bentley manual I have...need to know if yours is Fed or Cal.

[Petros]

Not that much time to write it up, but you know how it goes...I get started and one idea after another kept coming to mind.

Not likely a valve guild will make it smell like gas. And yes, you could have bad guilds and it will still run okay (for a while) and have good compression. These fail in two ways, either they wear and this usually wipes out the seal, this would cause bluish smoke from excessive oil consumption, especially when you down shift (on the intake valves) or right at start-up (the exhaust valves). The other type of guild failure is when the guide gets loose in the head and moves up and down with value. This will quickly get sloppy and start making noise eventually, though I drove on one like this for some time and did not even know it happened (I pulled the head off for other reasons and found it). This is usually caused by overheating the valve (it only occurs on exhaust valves) and it binds because of the tight clearance between the valve and the guide. This can also cause bluish smoke in the exhaust, especially right on start-up, though the exhaust pressure in the manifold usually keeps too much oil from leaking past the guild into the exhaust.

This may be an issue with your car, though it is not likely causing your current problem.

If you did not connect up all of the vacuum hoses correctly they it could behave just like it has a vacuum leak, so the first step I would take is to verify that they are indeed installed correctly. That is an easy thing to do, most people that work on cars, including professional mechanics will end up doing installing a vac line incorrectly sooner or later and allow the car to drive off that way.

[badmechanic]

One of those ports is the R port that goes to the vac modulator for the EGR...if you have the EGR (if it works) hooked up to one of the full vac ports that might explain things?

The R port only activates above idle.

Since you rebuilt the carb and redid the vac lines...I'd have to assume you've got something routed wrong.

I have an '83 and might be able to scan the vac diagrams from a Bentley manual I have...need to know if yours is Fed or Cal.

the engine i pulled i'm not sure if its fed or cal....but i do believe it has the feedback system to it, i know my engine dosen't match any of the vacuum diagrams, so i'll just take pictures, i'm on dialup so expect it to be a while hehe

[takza]

I actually managed to scan some vac diagrams from my Bentley manual...but my flash drive got deformatted so I don't have a way to get them online. Yet.

[CASE]

it sounds like you have a blowback carb, and many similar issues as my 3A-C. These things get dirty in the exhaust and intake valves(carbon shmek)which can make smoke when cold or gunning it- it may be worse if it ran with screwy vacum lines for a while. if you do your carb, then straighten out your vac lines and exhaust manifold, your intake will change alot and you'll have to do the carb again, so my advice would be to straighten out the vac lines first, expect some intake whackiness, then put together a good, sealed exhaust manifold( i used high temp sealer on my 1.75" flexpipe manifold-big difference! It's not like a chevy small block where you can just chuck your muffler and run fine) Then do your carb stuff last, you'll save a lot of work

[takza]

Scanned vac pics are here:

viewtopic.php?t=2810

[badmechanic]

that little vac senor looking thing that says gas f. whats that mine only has one line coming out of it, which has a lot to do with not getting the vacs right...as for intake and exhaust, new gasket....felt like lead to me. umm broke camera takin pictures =( but neighbor hehe maybe she'll lemme use it

[ARCHINSTL]

that little vac senor looking thing that says gas f. whats that mine only has one line coming out of it, which has a lot to do with not getting the vacs right...

That is a "gas filter." It sits on the intake manifold.
I just checked the AZ site* and my FSM (for '86); the non-feedback carbed cars have 3 lines at the filter, and the later Cali and Ca and Fed cars (feedback) have 2 lines.
Yours has just 1?
Maybe I missed it, but you have what kind of replacement engine?
Tom M.
*www.autozone.com/az/cds/en_us/0900823d/ ... oPages.htm

[badmechanic]

pics soon