1981 Tercel PCV and Breather tube setup

[irowiki]

Hello everybody! I have a 1981 Tercel 4 door sedan, 3AC engine, 5 speed manual with 210,000 miles that I just bought. I've been trying to fix various issues with the car, I was searching over at Toyota nation and somebody with a similar car was referred here, so here I go! I'm only somewhat knowledgeable about car mechanicals, I try and do the best I can on my own and with help from family so I don't have repair bills!

For reference, here's a picture of the engine bay:
http://sphotos-a.xx.fbcdn.net/hphotos-a ... 0959_o.jpg

Somebody, at some point disconnected the breather and pcv vent tubes and replaced the breather with a filter. Said filter is quite messy. I would like to hook the tubes back up, I can tell from the haynes manual that the PCV connects to a capped line right below the carb on the intake manifold. However, I can not figure out where the breather would have connected to, the only place I can find on the air filter is what I think is the HIC valve, a little white attachment on the bottom with two possible connection points. According to the repair manual I found on this site, that may not be it!

With that said, is there any advantages or disadvantages of either replacing the tubes, or leaving it as is? I'm thinking the lack of a proper PCV valve isn't helping matters much. Thanks!

[dlb]

welcome, irowiki. you are correct, the PCV hose closest to the firewall attaches to the HIC on the underside of the air filter housing. and as you mentioned, the PCV valve is connected to the large port located between the base of the carb and the valve cover.

looking at your engine bay pic, it appears the pcv valve is blocked off. this would be the cause of the messy aftermarket filter because the pressure and oil mist would have nowhere else to go but out through that filter. some people hate PCVs and are convinced that they cause poor engine performance due to blowby getting through but if an engine has that much blowby, it has far bigger issues than can be solved by plugging a PCV line. i would personally put it back to stock.

good luck with your work. there are lots of knowledgeable and helpful people on this forum and your first gen terc shares a lot of the same emission equipment, as well as the same engine, as our second gen tercs so feel free to ask away with any further questions.

[irowiki]

Alright, thanks a bunch, I couldn't find a single description of where the fire wall side tube was supposed to go!

There's a lot of fun stuff going on with this car, the previous owner ripped out most of the emission stuff because it was dry rotted, and took off all the mechanical stuff for the automatic choke, rigging it to the heater's temperature control cable instead.

[marlinh]

That sounds like a pain. How is the heater control connected then or do you have to pop the hood to make adjustments?

[Petros]

welcome to the list!

Actually with all of the systems working properly it runs pretty well, reliably and gets good fuel economy. the problem is if you are missing all of the vacuum operated stuff than you will have to hunt it all down and verify how to connect it and get it work properly. many of the systems not only reduce emissions but also improve fuel economy as well. There is sometimes a frustrating temptation to rip it all out if you can not find why it is running improperly, but that usually shows a lack of understanding on what the various systems do and how to test for proper function. This is likely what happened to your car.

Many of the systems can be by-passed, but you have to know what to block off and what to keep connected, just ripping it out could make it so it will never run properly. One place to start btw, is the service manual on this site, though it is for a different model of Tercel, most of the systems on the engine will be the same. I do not think your system has a high altitude compensator (HAC), but most everything else will be the same. Read though each system in the emissions control chapter and the fuel system chapter. the PVC will be in the emissions control chapter. Each system is rather simple and easy to test, it is just that there are so many, and they are mostly vacuum operated so it can appear rather clumbsy and complicated when you try and sort things out without knowing what you are looking at.

Where are you located BTW?

Good luck.

[irowiki]

That sounds like a pain. How is the heater control connected then or do you have to pop the hood to make adjustments?

I have to pop the hood, however the control wasn't operated in so long it has rusted shut! I may just replace it with a manually operated valve.

welcome to the list!

Actually with all of the systems working properly it runs pretty well, reliably and gets good fuel economy. the problem is if you are missing all of the vacuum operated stuff than you will have to hunt it all down and verify how to connect it and get it work properly. many of the systems not only reduce emissions but also improve fuel economy as well. There is sometimes a frustrating temptation to rip it all out if you can not find why it is running improperly, but that usually shows a lack of understanding on what the various systems do and how to test for proper function. This is likely what happened to your car.

With bad plugs, bad tires, bad oil and a plugged air filter I got 27 MPG pushing 75 on the freeway bringing it home which is more than I thought I'd get! Now that I've taken care of the tires/plugs/oil/filters I think it is going up.


One of the front brake pads was metal on metal and I'm going to replace the back brakes this weekend. Seems the more I run it the more funk gets out of it and she runs better! The most problem I've had is when we had a cold snap shortly after I bought it, she didn't want to idle. Dad figured out that the choke wasn't opening all the way, so we wired it open until I can find a spring for it.

There's a ton of disconnected tube fittings and electrical plugs and stuff, I am not even sure where I would begin if I start putting it back together. A few of the connections on the carb were bent to "seal" them.

I do not think your system has a high altitude compensator (HAC), but most everything else will be the same.

The air cleaner shell has had everything removed off of it except the HIC valve.

I've never been much of a gearhead but this is a pretty good car to start on I think! My other car is a 2003 Buick Regal and I've owned a 2001 Camry, 1995 Neon, 2005 Neon, and a 1982 Suburban.

Where are you located BTW?

Good luck.

Farmington, NM

Thanks for the welcome everybody, nice to find a Tercel forum that is active!

[dlb]

i guess you can see how well you can get the car running without all the emission stuff the PO removed, but considering what you mentioned about the disabled auto choke and bent ports on the carb, i might even consider buying a rebuilt carb and then grabbing the rest of the emission stuff from a wrecker.

that car is definitely a good one to start learning on. the vac hoses look intimidating at first but they are all actually crudely simple vacuum-operated devices. they are just hooked up to different parts of the carb or manifold so that vacuum pulls on them at a certain time, usually pulling a diaphragm which is attached to an arm that opens or closes something else. read through the emission section of the FSM and you'll learn what each thing does pretty quickly.

[irowiki]

Alright!

New PCV valve and new tubing:

http://sphotos-a.xx.fbcdn.net/hphotos-f ... 3390_o.jpg

Closeup of PCV tube going into the intake manifold:

http://sphotos-e.ak.fbcdn.net/hphotos-a ... 4133_o.jpg

Breather going into the HIC valve:

http://sphotos-b.ak.fbcdn.net/hphotos-a ... 5837_o.jpg

I'll keep an eye out for oil in my air filter, and for any difference in running.


Also, to add to the fun, figured out that someone yanked out all the fuel emissions stuff, took out the fuel filter, so now it goes from the tank, to an electric pump in the trunk, to some sort of T valve right by where the steering wheel enters the firewall, where it splits, one end going to the carb, the other end looks like it goes back to the fuel tank!

[ARCHINSTL]

No fuel filter? Better add one. Many with electric pumps recommend adding one before the pump, for its protection (similar to the OE mech pumps).
As to the pump - check the wiring to see if it is wired to the ignition or ? In the case of a collision, you don't want the pump to continue to run if the engine has stopped. Maybe newer pumps have some kind of integral safety switch; I dunno. Apparently many use a special oil pressure switch for power.
Did the PO mount the pump "exposed" in the trunk?
Good and informative link: http://www.how-to-build-hotrods.com/ele ... -pump.html

You might also want to bolt the air cleaner down to the cam cover through the holes provided. It's possible the normal shaking of the motor will cause the cleaner to oscillate a tad, eventually loosening the carb's bolts.
Tom M.

[irowiki]

Yes, mounted right in the trunk:

http://sphotos-a.xx.fbcdn.net/hphotos-f ... 6784_n.jpg
http://sphotos-a.xx.fbcdn.net/hphotos-s ... 9411_n.jpg

Someone suggested I remount the fuel pump outside, but I do not think the pump is weatherproof? When I replace the drum brake shoes this weekend I'll see if I can get some more pictures of what is going on underneath.

As soon as I turn the key on, I hear the pump start turning. I can try tracing the wires out and see what they did to it. The wire runs along the door jam along the bottom of the car out to the front. I don't think this was the PO I bought it from, I think it was a PO before him that did this.

Based off some other hack jobs done on the car, I'm not too optimistic, if I can figure out how to do the stuff in that article you linked, I'd do that. The only part I don't understand is using the oil pressure switch, is there a place on the engine to mount a second one?

We did mount a 2x4 in the trunk and put a box over it to protect it somewhat from items that may be in the trunk.

So would you put the fuel filter inline right there in the trunk, or should I put it between the trunk and the tank? Or take the whole thing out of the trunk?

Is there a resource somewhere that lists bolt sizes for various parts on the car like the air cleaner? I totally agree with bolting it down, I'll probably just need to play bolt roulette at the hardware store

Thanks again for the help and advice, it is very nice to be able to talk to people who actually know the car (if not my model, similar engines and such).

[dlb]

that's pretty freaky. i don't like the idea of fuel lines running anywhere inside the vehicle. i would personally pull the pump and mount it in the engine compartment. i would then put the fuel filter just in front of the driver side firewall, where it is normally found on these cars. there should be a little circular clip mounted on the inner fender in that area that the filter sits in.

do the fuel hoses shown in the pics connect the original steel lines, or is it hose all the way to the front? all hose, all the way, would also be a no-no.

no, no resource for bolt sizes unfortunately. however, we are lucky in that toyota used only a small variety of them on these cars so there are only a few options. best bet would be to go to a wrecker and grab a bunch of varying lengths, thicknesses, and thread sizes. they're all metric. remember that any 1st or 2nd gen tercel, and likely any 3rd gen as well, will use mostly the same bolts. there are tons of the hatchbacks around so just look for one of those and then start pulling.

[irowiki]

I'm pretty sure fuel lines coming out of the firewall connect to two of the steel lines, the third one is currently unused. I can get a picture of that if it'd make sense to someone. Between the haynes manual, the manual I found on the site here, and just poking around, I'm starting to figure out a bit more of what does what!

Is it okay to have an electric pump that far from the gas tank? Or does it not matter since the Tercel is pretty short?

It is funny, I went to two junk yards near here, and none of them had anything from the 80's, I was like "Really?" The car sure gets looks though! People I drive by on the street stop and look, and people keep commenting on it at work!

[dlb]

that's wild. i've never had problems finding various 80's tercels in wreckers, but they are getting old enough that they will become scarce.

yes, there are 3 steel fuel lines. with the stock fuel pump, the inlet line goes from the tank to the pump, a return line goes from the pump back to the tank to deposit unused fuel, and a vent line from the tank to the charcoal canister which then connects to a port on the carb. the charcoal can collects gas fumes which would otherwise make your car stink like gas and allows the carb to burn them when it is appropriate.

i'm not sure about how far electric pumps should be from the tank. i honestly have no experience working on them. if you do a search on this forum for electric fuel pump, you might find some useful info though. i know other guys have talked about them. i just wouldn't want the pump inside the car, and i wouldn't want it underneath the car by the tank either, so that would only leave me the engine bay. i'd probably get a stock fuel pump. i'm exceedingly unadventurous when it comes to cars but that's the way i like it.

[ARCHINSTL]

That exposed pump and tubes - if you got rearended and sparks flew...
Honestly, you are courting disaster.
Obviously you don't have safety inspections where you live. No insurance company would countenance that, nor would any real wrench - or their employer.
Most electric pumps work better as pushers rather than pullers - the reason they are mounted in the tank (and to keep them cool).
That said, many (most) will work fine in the engine bay - others will speak from more recent experience - my experience goes back to BritMobile SU pumps of years ago, many of which were mounted in the bay.
Tom M.

[irowiki]

Alright, I'll look into mounting it (or another pump) either in the engine bay or under by the tank.