all of a sudden, it dies at idle...

[Petros]

I can likely find you a used working one here if you can not locate one locally. There are two solenoids on the carb. which one is it, the one above the throttle crank, or the one on the side where the valve cover it? PM me if you can not find one.

But long before I would pay $400 for new carb, I would go weber.

[SethM]

Thanks for the offers/advice Arch and Petros. But.....this afternoon I had more time and repeated the test of the "first" fuel cut off solenoid. At least I think its the "first" which Is FSM-speak for the solenoiid by/under the throttle linkage not the "second" on the side of the carb closest to the valve cover. The FSM is most unclear (to me) as to which is which but I THINK it is as I just described. I can't figure out how to do the test prescribed in the FSM without cutting the wire. This morning I tried to test by inserting a pointed lead through the wire casing and thought the solenoid was no good. But the casing is pretty hard and I wasn't sure I was hitting the wire so this afternoon I cut the wire and toched it to the pos terminal on the battery while grounding the vody of tge solenoid. It clicked so I guess it IS good. Oddly the "first" solenoid on my 85 T4WD has only one wire (as does the "second" while the FSM depicts the ofirst" having two wires and the "second" only one. ?? Guess i'l test the "second" tomorrow but wondering if there is another way besides cutting the wire? And, I'm no nearer to solving the sudden lack of ability to idle than I was when this all started on Saturday.... Sigh...

[Petros]

stab a sharp pin (used in sewing) into the wire insulation, attach your test lead to the pin. Make sure you unplug the connector. First or second, both need to be working. I have found them to be fairly reliable, but they do fail occasionally.

YOU MUST sort out your vacuum lines before you replace any parts. IT will never run correctly if any are leaking or mis-routed. Check and double check. Use carb cleaner to look for leaks (with the engine running spray it over the various lines, gaskets, manifold and other parts, when the engine speed changes you have found a leak that is sucking in carb cleaner). Simple test, works well. But all of the lines have to be routed correctly.

I picked up a "broken" T4wd cheap, I fixed the rear diff and brakes, but when checked the vac lines: I found 9 vacuum leaks, including several hoses just hanging loose, and several cracked lines. It was undrivable and hard to start. Now it runs and starts great.

[ARCHINSTL]

I would certainly echo (and emphasize) Petros' comments about the vac routing/quality of existing tubing and as a first attack on the probs before all else..
Did you check the color-coded diagrams (saved as a Sticky in this Forum)? Note that they are for Federal cars.
Also check for a vac leak around the manifold. I had one of those and it was pretty subtle.
These engines with the OE carb and emissions plumbing have so MANY places for a vac leak... I had a particularly vexing one - see http://www.tercel4wd.com/forums/viewtop ... it=cycling and the quite lengthy http://www.tercel4wd.com/forums/viewtop ... it=cycling.
Note on the solenoids - member 4wdchico has mentioned that the positions of the solenoids are occasionally reversed...Fun!
tom M.

[SethM]

I will keep looking for vacuum leaks. As far as routing errors- I have been driving this car on a daily basis for almost a year now and have always gotten 33 mpg on straight highway driving and 29-30 around town. I don't think there is a routing error and one certainly didn't just develop last Sat at the stop sign. This is a sudden change in this wonderful car's performancevwhich leads me to look for leaks and other failures that could happen suddenly. Wondering now about a second of dirt n the carb in the wrong place.....

[SethM]

PS how do I do the carb cleaner test if I can't keep it running? The fast idle seems so fast (2000 rpm) as to obscure the boost from the carb cleaner.

[ARCHINSTL]

Well - as to routing errors and economy...when I got the car in '05, the TVSV was broken, leading to all sorts of vac leaks - there was also at least one (and possibly two-I forget) routing errors. And while the car ran like crap and 55 mph on the Interstate was the top - it still got 33 mpg on the trip home - which took 7 hours to drive 290 miles, 99% of which was on Interstates.
Tom M.

[takza]

I recently got water in my carb...doing a carbon flush. So I went thru all the vac tubing ends and though none seemed loose to any extent...I put small nylon cable ties on most of them...this solved the problem somehow. Poor to no idle.

Takes PATIENCE! First...do them all...one at a time...don't worry about routing. Then do the routing...being real careful how you LOOK at the diagrams...they look too much like some of those Escher drawings?

If you have the attitude that you don't have a problem...you won't fix it?

http://www.mcescher.net/

[SethM]

If you have the attitude that you don't have a problem...you won't fix it?

Sorry if I gave that impression. What I was trying to convey/stress was that this problem started suddenly, at a stop sign. I am not trying to suggest I don't have a problem. I have a rather big problem.... it won't stay running at stop signs etc. It seemed to me that the emphasis on routing was accompanied by stories that related to cars that had were acquired in poor condition and THEN fixed by paying attention to routing issues. My car ran well (not just economy, but smooth running) and then suddenly couldn't hold an idle. To me, this is not indicative of a routing problem. A hose could crack suddenly but it is not likely to change its routing position. Even if something is mis-routed, that can't explain the sudden appearance of the problem. This is why I have been concentrating on hose connections, solenoids, and wondering about just dirt in the carb. Those kinds of things seem consistent (or possibly consistent) with a sudden change in performance. I do appreciate all the advice and expertise I receive on this forum. It makes owning a 1985 car (mostly) a painless experience!

[dlb]

seth, does it die at idle regardless of being hot or cold? if it first happened at a stop sign in the middle of a drive i imagine it happens even when it's hot but thought i'd ask, just to try to narrow down the possibilities.

[tercel4wdrules]

One of my cars has a similar problem, when I came to a hard stop it would stall. I know it's not exactly the same problem as yours, but somewhat along the lines. Restarting the engine would yield a weak idle sometimes and it needed to be revved a bit, but it wouldn't refuse to idle. It's not driven at all just sits and I work on it whenever I can. I swapped the carb with a known working one from another one of my cars and that cured the problem, no stalling at all anymore. My guess if all of the hoses and everything are correct, then maybe your problem might be within the carb itself, I think it's very possible. With the carb being this old, I wouldn't dismiss the assumption that something could go wrong without any anticipation signs or warnings. I have found that one of the easiest ways to troubleshoot the carb is to swap it with another one (a presumably working one that is), I'm sure xirdneh can vouch for the same answer. However, I know that most of you guys don't have several 3AC carbs lying around like some of us do...

[SethM]

Unfortunately, I do not have a pile of spare carbs laying around... or even one spare for that matter As for the hot vs cold question, good question. It definitely won't idle (at all) when hot. As for cold, that is a bit hard to tell because when its cold, its choked and up on the high idle setting. If I kick it down off of that, it dies but is that because its cold and not properly warmed up or because of this new problem? My guess is that it won't idle when hot or cold. It did seem to idle (well in fact) when cold that one time right after I changed a few hoses and installed a new PCV valve but then it died when warm and has been dying ever since.

[xirdneh]

[quote="tercel4wdrules"]carb is to swap it with another one (a presumably working one that is), I'm sure xirdneh can vouch for the same answer. quote]

Hey, I'm doing a carb swap this morning
"the only way to fly"
i've picked up a few carbs over the years and re-build or dissasemble and clean when i have some spare time (usually on rainy winter days)
these carbs malfunction easily with a little water or dirt
swapping takes about 30 minutes and solves problems

[SethM]

carb is to swap it with another one (a presumably working one that is), I'm sure xirdneh can vouch for the same answer. quote]


i've picked up a few carbs over the years ...
swapping takes about 30 minutes and solves problems

Well, I wish I was in your shoes (or had your spare carb supply). I finally took it to a mechanic I know who I use when I've reached my aptitude limit... He said its definitely a carb problem as its not getting fuel at idle. He also thinks the intake manifold (gasket) is leaking a bit. But on the carb front--- where are you folks picking up all these spare carbs? OR, is there a concise guide to the Weber swap? I did a search and found mention of a write up by Splatterdog but wasn't able to find it.

[ARCHINSTL]

There are a number of threads by splatterdog, alehander, keith, moi, and others. Many have photos. I would suggest performing a Search using "Weber" and then inserting the name of the member in the next box.
Tom M.