Throttle sticking after carb rebuild

[Notmikeb]

When I had the carb apart I checked both solenoids on the battery and they both clicked.

[xirdneh]

i cut the solenoid wires also and use blade connections to re-connect
one time i could not stop the cycling
found out that some tercels have two wire solenoid on back of carb and some have it on driver side
so i swapped them and the cycling stopped
ya never know

[Notmikeb]

Well I have a broken TVSV valve. The lowest port was not fully attached and is now completely broken off. I don't know if it was the problem but it sure is now

So now the question is do I throw in the towel and buy a weber kit or invest in a new TVSV valve and hope that was the problem? I don't have to pass smog here as I have the car registered as a "Historic Vehicle". After finding that vacuum hose blocked off from a previous owner's attempt to fix something I can only imagine what other goodies are awaiting me throughout the vacuum driven emissions components of this car. Is there a way to temporarily reconnect the lines bypassing the TVSV that will at least let me test the car to confirm if that was it or not?

Any good and cheap(er) source of new TVSV valves? I found a few Toyota parts dealers online but they all want $130 or so for a new one and I haven't seen any junkyard tercels around my area to grab one from.

[Petros]

they were used on all models of Toyotas that had carburetors, not just the Tercels. Usually the junk yard ones are shot as well, unless you get luckly and someone recently replaced theirs before it went to the wrecking yard.

I think they show up on ebay every so often cheap. You can temp repair it with epoxy and perhaps using fine wire to wrap and hold it in place. Or check out what that port does in the FSM, and see if you can either by pass it, or just cut it out of the system if it is only necessary for say cold running.

[Notmikeb]

It was the port going to the AAP. I suppose I can just seal it shut and leave it disconnected for now. I'm really thinking that it wasn't the leak however. The car actually runs pretty well when cold. Cycling rpms don't start until it warms up a bit and the choke starts to open up. I would assume that at that point the TVSV should start to close off that port anyway so if that was the source of my vacuum leak I would most likely have the opposite problem (rough when cold, better once warm) right?

[irowiki]

If it starts when warmed up then the choke breaker or choke opener is probably the culprit unless the electric choke is not working

Unfortunately both the choke breaker and choke opener require a working TVSV

[ARCHINSTL]

You might peruse this old thread which I started and had 65 (!) posts. This may give some further insight.
Eventually I tired of it and installed a Weber after fighting it for two plus years - even with a reman carb.
With the Weber, I ditched ALL of the emissions stuff, save for the cat - and that may go soon, as it is almost rusted through (new in 2005).
viewtopic.php?f=4&t=1372&hilit=cycling
Tom M.

[Notmikeb]

So I was chasing this thing until 4 am last night. Swapped the solenoids as xirdneh suggested. Made it idle worse.

Noticed that the choke opener wasn't doing anything and had no vacuum when warmed up. Chased the vacuum lines on that loop and found that bypassing the egr vacuum modulator brought vacuum back to the choke opener. Tested the modulator and found it was working as it should. When running, there is no vacuum coming from the EGR tube at the bottom of the modulator (is there supposed to be?).

When the EGR system is removed from vacuum and the lines capped or routes into each other (I did both depending on what seemed to make sense given my understanding of how it works) the car stopped having the cycling rpm issue but generally otherwise ran like crap. I'm going to pull the EGR valve next and see if I find an obvious problem and then most likely do the full EGR delete next as at least then I can isolate that system as the source of the problem.

At this point though, if the problems persist, further diagnostics will be purely academic as in a fit of frustration last night I ordered the K740 Weber kit. I figured I'd pull the EGR system anyway for that so I'll keep everything else intact and see how good I can get this car to run on the stock carb if for no other reason than to have that available as an option should I ever want to return the car to the stock configuration. Mostly though, I just really want to figure this problem out regardless of whether it's staying on the car or not.

[ARCHINSTL]

I ordered the K740 Weber kit. I figured I'd pull the EGR system anyway for that so I'll keep everything else intact and see how good I can get this car to run on the stock carb if for no other reason than to have that available as an option should I ever want to return the car to the stock configuration. Mostly though, I just really want to figure this problem out regardless of whether it's staying on the car or not.

Did you ask for the "short" aircleaner? Most show only the "tall" one, which will not work - call to make sure. Not all vendors will swap even for this, however.
Even with that, I had to cut the element down and also remove some of the bracing on the hood.
See viewtopic.php?f=7&t=5857&hilit=air+cleaner
Now, that was because I left the preheater in place under the carb. Getting the supplied adapter to fit was close to being a PITA.
As mentioned, I got rid of all of the emissions, including blocking off the EGR tube from the manifold. Note also comments on the mani studs in last post of previous link.
See The plug for the EGR's pipe-to-exhaust manifold, anyway, should be a 20x1.50 (metric) bolt, with washers; ditto if this pipe hooks into the front of the manifold.
And for linkage: viewtopic.php?f=7&t=4497&p=33319&hilit=+weber#p33319
Tom M.

[Notmikeb]

All looks like good advice. I got the 1 7/8" air cleaner which is the smaller of the two they have listed. I manage a bicycle store so finding a cable anchor bolt shouldn't be a problem (I have a bin with probably 30 of them. I'm a bit of a fastener hoarder.)

Tonight I'm going to dig through my pile of metal scraps and see if I can find a piece to use for an EGR block off plate. I picked up a 20x1.5 drain plug on my way home today. I'm going to start off by removing the EGR and seeing how that changes the idle cycling issue on the stock carb. I've already spent the money so the weber is going on no matter what but I'd like to have the stock carb setup working as best as I can in case I ever have to switch back. My wife keeps talking about wanting to move back to California and I can only keep trying to renew my MD plates from across the country for so long before CARB catches on

[Notmikeb]

EGR valve was as plugged as plugged can be. Carbon deposits were completely clogging the valve and the Intake port. That probably wasn't helping anything... (Annoyingly this meant I had to pull the carb off again to clean the intake out from the inside pushing out so I didn't drop 30 years of carbon deposits down the intake all at once.)

I made a small block off plate out of some scrap 1/8" steel I had in the garage. It's ugly but it will do the trick for now. I may make something nicer looking out of aluminum next time I find a good piece of scrap. I imagine the steel will rust up in no time. I didn't have a new gasket so I used some grey RTV under the plate. I think it will hold up just fine and if not I'll source an appropriate gasket.

I then installed a 20x1.5 drain plug in place of the original pipe fitting.

At this point I'm debating the merits of putting the original carb back on since I had to take it off anyway. We'll see how motivated I feel tomorrow but I'm calling it a job well done for tonight.

EDIT***** I am now wondering if I should have put a copper washer under the drain plug. I'll pick up one of those tomorrow.

[Petros]

my EGR looks like that. I left it in place, it makes a perfect plug and appears to be a "decoy" EGR from anyone looking at it.

[Notmikeb]

I'm not going to put the stock carb back on before the weber gets here. I pulled out all the emissions stuff on the passenger fender wall today and pulled all the vacuum hoses and metal lines. I left the one metal line that runs along the back of the engine to the distributor in case it makes sense to use that for one of the two advance hookups I will need.

At this point, this is no longer relevant to the original problem so I will post any interesting updates or questions in a new thread if necessary.

[ARCHINSTL]

I had to put a couple of washers under the EGR plug; shudda mentioned that - sorry. I also put an EGR gasket under the aluminum blocking plate I made; I figgered it was necesaary, as that hole opens to the carb.
Ditto on the single metal line.
Good on pix of the installation. It seems all of us who've installed the Weber have done things just slightly different.
I figgered you would have some of those old cable anchor bolts from center-pulls laying around!
Are you going to get a fuel pressure regulator and gauge? Some have - some have not. The mech pump puts out too much pressure.
Tom M.

[Notmikeb]

I am going to do a fuel pressure regulator. I picked up a Holley FPR today and attached it to the fender where the emissions stuff used to be. I already pulled the EGR line plug out and put a copper washer inbetween it and the manifold.