85 T4 carburetor Ok on an 83 T4?

[DanT]

I think I can do this, but thought I better check. Both SR5 cars have stock 3A engines and stock carburetors. I was planning to just mark the hoses when I pull the carbs and then match up the letters when I swap them. (The 85 runs better and I want to see if the carburetor will help out the 83.) If someone could confirm that this is ok... or not ok... that would be great. Thanks. Dan T

[Petros]

You can make it work, there were a few slight differences over the years, mostly in the vacuum routing. If you have a difference you can often use T connectors, or something similar, to reroute the vac from the same source.

There were also several different jet sizes used from year to year, likely due to changes in the emissions requirements. But this should not affect the swap.

Just inspect everything carefully before you pull it so you know where they are different before you take it all apart.

[tercel4wdrules]

There are a few differences between the carburetors. The biggest one on the carburetor itself is is that the 83 doesn't have a port on the bottom part of the body of the carb and so instead of the yellow "jet" being hooked up to this vacuum port, it hooks up to one of the metal lines. The vacuum routing is a bit different as well. The "gas filter" on the intake manifold only has one port on the '83 models instead of two on the '84 and later models. This said, it can be made to work with some workarounds. I've always used the appropriate carb, but I have bought vehicles with the wrong carb on them.

[DanT]

I had a mechanic look at my carburetor today. He said that the current carb is full of vacuum leaks and is not worth working on and recommended that I get a new carburetor. I am thinking about doing this rather than pulling the carb off the other car. Has anyone done business with Guaranteed Carburetors? Web site and prices look good.

http://importcarburetors.com/contents/en-us/d25.html

It appears that I could install a carb from these guys by myself with only minor adjustments?

Other suggestions would be great also.

Thanks.

Dan T

[dlb]

if the problem is purely vacuum leaks, which could very well be the case, they are easy to sort out on your own and for very little $$$. just pick up a can of carb cleaner and 15' of vacuum hose. first off, simply carefully inspect all of the vacuum hoses for cracking, tears, or being disconnected altogether and trim the bad ends, replace the whole hose, or just plug it back on to wherever it's supposed to go. once that's done, start the car up and spray the carb cleaner all around the hoses and base of the carb. if there is a vacuum leak, it will suck the cleaner in and the revs will increase (or drop, i can't remember which offhand).

the FSM has good instructions for checking each component of the emissions control systems so you could also go over each of those to make sure all are functioning, which you should probably do even if you do go with buying a new carb.

the prices in that link are certainly not bad but i would try the above first and see where it gets you. it will take time but it will save you $$, and more importantly it will increase your knowledge of how the carb works. i think that's the invaluable part of it.

[DanT]

Very helpful advice. I will do that today. (My experience with carburetors is a weak spot for me as I have only set the idle screws before. I did pull a carb once and slap it on another car, but I only matched the hoses when I did that ... and never got any further into the operational parts.)

I am taking this car on a 2,400 mile round trip to Minnesota leaving on Sunday morning, so there is no way to get a new carb here by then anyway. I would really like to get this one running better before I leave if at all possible. Hesitant to pull the carb off the 85... as it does not match up exactly, and that does not solve the problem for both cars to have a carb anyway.

It idles poorly, and I am not able to adjust it with the idle screws. Runs too low after starting, and then if I set the idle screw higher it runs too high after warming up. When idling it "farts" a lot. Not actually popping, but it is not smooth like the 85... or as smooth as this car use to be. Seems ok at driving speeds, but I cannot tell what is going on inside at those speeds. Guy at Autozone looked at the plugs and said it is running too lean as the plugs are very white. I think it will make it to Minnesota (?), and I was thinking of putting a new carb in there... if I need to... as I will be there for 2 weeks.

"if there is a vacuum leak, it will suck the cleaner in and the revs will increase" This is what the mechanic at the shop did and he told me there were a lot of vacuum leaks. (inside the carb and maybe outside also) He said it needed a new carb and it would be about $300 in labor to put it in. So a new carb for $190 that I could slap in myself appeared a much better option! By the way, they were so impressed with the car that I did not get charged for the diagnostics. Needed an alignment, which they did, and that is all they charged for.

I was at Autozone pricing a new/rebuilt carb. They could get one through National for $250. Just found the National site and see they sell direct for $149. Same rebuilt carb without the markup I would think? If I need the carb this appears to be a good name and a good price?

http://nationalcarburetors.com/cat-toyotacar.html

Thanks again for the advice. I was wondering what to do with the current situation. Definitely a good place to start with the hoses and a can of carb spray. (I would replace all of the hoses with a new carb anyway.)

Dan T

[dlb]

i admit that carbs are not my strong point either but i've learned a few basics about them so far.

definitely sounds like vacuum leaks by what you describe. follow my advice above and see where you get, and if it still idles low when cold then it sounds like your choke needs adjusting, which is no big deal, but all the vac leaks need to be sorted out before changing any settings. a lot of the other components need to be checked too though, like the TVSV (the little tree-like thing attached to the intake manifold with 6 ports on it) and your vac advance canisters (located on the bottom of the distributor). these things can all malfunction and wreak havoc so it's best to check them all out along with the vac lines. once you are satisfied that all the vac leaks are taken care of and all the various components are in good working order, then re-check the timing and put in new plugs. if it's still running too hot (as indicated by the white spark plugs), get new plugs that are one heat range colder and pull them after driving for a few days to check their colour. ideally, they should be a milk chocolate brown colour. here is NGK's explanation of spark plug heat range:

http://www.ngk.com/charglossary.asp?kw=Heat+range

i don't think there will be any internal vac leaks in the carb. could be, due to gasket failures, but from what i've gathered here that's extremely unlikely. the hoses are the usual culprit due to the rubber breaking down after 25+ years of heat exposure.

good luck, and happy new year!

[DanT]

OK. I printed off your post and will go to work on this today. I have an 85 parts car with an extra TVSV and vac advance canister... that might be good. (One-owner car with 110k with a shot body/frame. Motor ran fine before being parked 15 years ago.) Not sure how to tell yet if my parts need to be replaced? I will check the manual. Thanks for the tip on the plug temps. I did not know about that... and it makes a lot of sense now. Seems like part of the performance issue might even be addressed with plug temp. Have a ton of other things that need to get done today before I leave in the morning. Will see what I can do with the carb. THANKS!

Dan T

[dlb]

plug temp won't make a huge difference but it will keep the metal posts on the plugs from literally melting away. i checked mine and they had melted to tiny little points. i couldn't believe it ran fine regardless.

parts cars rule! it's so great to have all that stuff at your disposal. just check the FSM for testing all the different stuff, each component only takes a few minutes.

off to party!

[ARCHINSTL]

That is a great price on a reman carb from National! I got one from them in the Fall of '05 for $165!
I was happy with their work. I did have a prob after 8-9 months with some clogging and bad AAP diaphragm. I sent it back, they cleaned it, and sent it back via air at N/C. You will have to do some fiddling with the adjustment, but nothing taxing.
If you go with plugs, go with the NGK G-Power (word?). That seems to work the best for us. Do a Search here on the right NGK plug - am not at home and memory is being affected by age (although a little Heinekens may be playing a part as well; dang son-in-law does not stock Bass or any of our fine STL microbrews - at least it ain't Busch...).
Tom M.

[DanT]

Tom,

Very helpful to hear that you are running the National rebuilt carb. Thanks. A guy at AutoZone recommended NGK #7634 plugs. I bought a set of 4 plugs but have not installed them. I just looked up the G-Power plugs. Part #7082 for the 83 tercels. I will go with the experience of the group on this one. Should be easy to swap the plugs.

I checked my notes and this carb was actually taken from my first tercel. I put the carb on this car myself. It has tons on miles on it... and nothing has ever been done with it to make it run better. If I cannot get it to run well enough I think the path of least resistance is to go with a rebuilt carb from National. They say I should be able to bolt it on and go. I do not see a need to involve a shop for installation. The last few pages of the FSM should give me what I need to adjust the choke, slow idle and fast idle... if anything is needed. (National says all of the should already be set correctly.) I will install all new vacuum lines... even though the rubber on these looks very good.

Please correct me if I am fooling myself?

Thanks again for the advice.

Happy new year to all!

Dan T

[Petros]

you are likely on your way by now but for what it is worth, not likely you need a new carb (possible but not likely). Check for vac leaks, that is your problem with both the rough idle and lean run (white spark plug deposits). A vac leak will make it run lean and cause the overheat condition on the spark plugs. Check your gaskets at the manifold as well, the bolts and nuts work loose with the expansion and contraction from the heat of the exhaust manifold. Just tight them as much as practical (some are easy to reach, some you can get to by bending the heat shield a bit, and some you can reach from under the manifold with an open end wrench-takes a mirror and flash light).

IF you do go with a rebuilt carb I would NEVER pay a shop $300 to replace it. IT is only about a 20 min job, even if they are so slow and incompetent to take an hour it should still not cost anywhere near $300 in labor.

Replace it your self if you do get a reman. carb, but it does not sound like you need one. check vac hoses, the vac components, and the manifold gasket for leaks. Also if you run some fuel system cleaner through your fuel system on your trip it might help clean any sludge out of the carb. You can also carefully take the top off the carb (without removing the carb from the engine) and clean it out. Watch out for the tiny parts and gaskets, but that is all I have ever done with my carb (replaced diaphragms and the accelerator pump, but neither requires removing the carb).

Good luck on your trip. Even with vac leaks it will not leave you stranded, it is just annoying.