Mike's 85 FWD 5dr Tercel

[Notmikeb]

Good suggestion on the paper. I have about 10 small parts bins that I've been using to categorize small parts I take off so I can keep systems together. I had thought about using loctite in those bolts too so after your recommendation I absolutely will.

[Notmikeb]

Well the carb rebuild didn't go so well. I don't know if I bungled the process and missed something crucial or if I somehow awoke the vacuum leak demons living in this car but it just wouldn't run right after I reinstalled. Something in one of the systems that comes online after the car warms up.

viewtopic.php?f=4&t=11479

The TLDR version of the above thread is that I hooked the vacuum lines up the way they are supposed to be routed and I think I undid whatever "fix" a previous owner had done to bypass some leaking systems. I threw in the towel and ordered a Weber carburetor. Because I like documenting things I'll do a full photo walk through of my install process even though this has been covered already many times on this site.

[irowiki]

Why did you rebuild it in the first place again?

[Notmikeb]

Rough idle and a flat spot in the acceleration. It definitely needed it. The carb was really filthy inside and the accelerator pump plunger had dried and cracked up.

[Petros]

if you put the carb together properly the problem in likely not in the carb. Best to actually isolate the problem to make sure you do not go to a lot of trouble and expense trying to fix it, and find out you still have the problem.

It is important to ALWAYS diagnose the problem BEFORE you try and fix it.

[Notmikeb]

I agree, the problem was not likely in the carb but in one of the vacuum driven components. It was the broken TVSV that made the decision for me. I didn't want to invest in a replacement just to change the carb anyway. And yes, I know they can be fixed sometimes.

I also just really wanted a Weber since the first time I read one of the install guides on this forum. I think the look is better and there's less clutter to the engine compartment.

In short, the more practical approach would probably have been to finish diagnosing and fixing the issue but maybe I was looking for a reason to change it anyway. This car is not my only mode of transportation and was intended to be a hobby car.

I see it all the time at my job in the bike shop. Someone comes in with a problem with some part and all they want you to do is give them a reason to upgrade even though all they really need is some adjustments done. For some people, the modification of the machine is half (or more) of the fun.

Anyway, Enough self psycho-analysis for one day

[Petros]

the weber is not a cure-all, it has its own set of issues. I think the stock induction system actually has better driveablity, and it is better for extreme cold and hot start ups. Fuel economy is similar between the two once you get the jetting sorted out properly on the weber.

A lot of those vacuum operated stuff on the factory induction system is not just for emissions, but also improves fuel economy, and drivablity when it is very hot and every cold, and also has altitude compensation. The old carburated engines ran like crap at high attitude, perhaps not a problem where you live, but the first six cars I owned were uncompensated traditional carb engines, every time I went to the mountains to go climbing or skiing, it ran like crap, not just down on power but clearly it ran too rich. The later more complex compensated carbs, and than the EFI, are such an improvement over the old set up that I think most are not even aware it was ever an issue. The weber takes you back to the old simple carb set up.

Some claim the weber improves performance, but it is not much if at all, I have own Tercel4wd with both stock and weber setups, and driven them both cross country. One benefit perhaps, besides the simplicity, is if you do attempt to tweak the engine to get more power, there are a lot more jets and information available on how to optimize the carb to the non-stock engine configuration.

[Notmikeb]

Not sure if power increasing mods are in my future. Seems like this is the wrong car for the power hungry. Maybe do the delta cam re-grind if I ever have to do a head service anyway. The sales guy I ordered the weber from said that they custom jet the carbs for each kit and it should be fine as it is for my application and altitude but time will tell. It looks like there are some good parameters to be able to tell if it is jetted appropriately depending on how the idle mixture screw is set. I am saving all of the Aisin carb related parts and storing them carefully in case this doesn't work out and I want to switch back.

[Petros]

If it comes jetted for the car that would be great. Some have had good luck with that, but there still could be something to be gained by fine tuning the various jets further. Some on this forum has had to change them, as I did, and some have found the ones that came in it good enough.

That was one of the selling points to the webber way back when they were popular to install on your stock VW or Datsun or whatever (back when I was in high school). They had jet kits that came in small increments to allow you to fine tune all parts of the operating range. There are high speed jets, low speed jets, and air emultion jets, plus the idle mixture screw. The idle mixture screw is only for when the throttle is at idle, and just slightly off idle, after than the other fuel supply jets take over, I do not see how the idle is going to tell you much about the other end of the operating range. Best way to tell is fuel economy and acceleration, short of a dyno test or an exhaust analyzer.

There used to even be carb shops that specialized in weber conversions, using CO meters to get the jets set properly, not likely many of those kind of shops around anymore. But there is a lot more information available over the internet, so you can DIY without having to be an expert.

[Notmikeb]

Got the weber installed today. Only hiccup was figuring out a good linkage system for the kickdown rod but that is all worked out now. I took it for a short drive and it's amazing how much faster it sounds!! Note that it doesn't actually feel any faster but boy does it sound cool!

The other thing that seems a mystery is where to hook up the charcoal canister. The instructions that came with the carb point to a port on the carburetor but label it optional and near as I can tell there is no vacuum at that port nor threads to attach a fitting. There's a hole but it doesn't seem to go anywhere and it looks blocked off on the inside. Can I tee into the breather line or should I have it attached to manifold vacuum? The other option is to route it under the car somewhere as I've seen done here but I would prefer to play by the rules as much as possible and don't really enjoy gas fumes.

[dlb]

re: the charcoal can and the weber, see #14 in the faq:

viewtopic.php?f=2&t=7442

[Notmikeb]

Well. Bitter sweet end to the day. I figured out what the original problem was. Vacuum leak at the distributor advance. The line that runs off manifold vacuum does nothing.

I had replaced my distributor awhile back with a used one and nothing changed so I made the assumption that both distributors must be good and the problem lay elsewhere. Nope. Both are bad in the exact same way. Neither vacuum advance units hold vacuum from either of the top ports (ported vacuum holds fine and advances the timing as it should). I confirmed this by taking off the cap and attaching a line to both of the fittings while capping the other and sucking on it. Wouldn't hold and the distributor did nothing.

I really should have caught this much earlier but I didn't follow the procedures for checking. I just assumed that if changing the whole distributor did nothing then they both must be good and moved on.

I feel like smacking my head repeatedly against a brick wall.

Oh well. I've got both the upper ports capped and the manifold gas filter capped as well. I left the bottom port connected since it's doing what its supposed to. I'll replace the vacuum advance unit someday.

The car runs unbelievably well now. I have power I never knew I had. Smooth idle, no hesitation, no pinging. Perfect.

Now on to the cv axles .......... Next month I think.

[Notmikeb]

After finding a few broken a/c lines (twisted off at the fitting I'm assuming during a PO attempt to fix), I decided I was never going to bother fixing the a/c as I generally prefer windows down driving in my cars where it does work. I pulled out all the a/c components as it was just useless clutter and weight.

One thing concerns me though, there is a big empty space where the condensor was. It seems like any kind of road debris that makes it past the grill is going straight into the engine compartment. Also it seems like all the electronic goodies (alternator, starter, fuse box, distributor etc..) are on that side of the engine compartment. Do non-a/c cars have anything there to block that or am I just over thinking this?

On that note, anyone need any a/c parts? It seems like the compressor clutch at least attempts to turn on so it probably works but no promises on anything.

[rer233]

Non a/c cars had a plastic block-off plate in place of the condensor (you can prob make one out of a piece of plywood- don't think you'll find a factory one- very rare.)

[Notmikeb]

Hmmm... I might just put it back in there then. Maybe I'll flush it out and turn it into an oil cooler for the transmission.