Diamond in the Rough - my 1985 Toyota Tercel build

I have a collector/antique plated 1992 Tercel. I'm more of a Corolla fan, but i really liked the condition of the Tercel I found. What are the rules aroumd your antique plates? Here in BC, the car must be bone stock with zero rust, and no mods unless it is a period correct stereo.
The 4wd Tercels were always pretty neat. I remember the manual transmissions had a 6th extra low gear that could only be engaged if 4wd was engaged.

 

No, it's a part-time 4WD system. It functions similarly to a vehicle with a "transfer case" to send power to the other set of tires that isn't typically driven.

 

They weren't too fussy with me getting my historic vehicle title. I believe there are some stipulations about it remaining a mostly stock vehicle, but there was no inspection to speak of.
Yes, the manual Tercels certainly were better off in the way of their extra low range transmission with 5 standard highway gears, far better than my 3 speed automatic. But I must say, as someone who drives in and out of the city quite often, having an automatic transmission has been great.

 

Every few months when I see a clean one pop up on craigslist out here, I must resist the urge

 

Do it! If you have the room in your "stable", I say go for it. These things aren't going to be around much longer. Scoring a clean one is a rarity, and even if you aren't doing it for the money, the value of these are bound to increase.

Most parts are readily available, with some small exceptions.
The Tercel4WD community is tight-knit. Members help each other out scoring parts & vehicles, assisting with tasks etc. I am active on their FB page and forums.

They are great economical, fun lightweight vehicles. Engines are not powerful, but they are very easy to work on.

 

Hey man I recently pretty much gutted my 83 Dlx motor compartment out. Ac compressor , factory carb and all the emissions junk. If you need parts let me know.

 

Oh wow, thank you for that offer! I appreciate it. I think at the moment I will hold off, but I will keep this in mind in the future.
I have all my original emissions gear and factory carburetor boxed up for future use, should I decide to swap back from the Weber carb.

 

I actually may have a request. Did you keep the intake manifold vacuum port installed on your Tercel (the one circled in purple), or did you gut that too? If you've removed it and it's still in decent condition (the two ports aren't broken), I may purchase that from you.

 

Let me look through my extra parts bag lol, because I still used a single on that port for my vacuum advance sine the Weber did not have two vacuum ports. Also I see you couldn’t get that egr out of the exhaust manifold either.

 

I'm guessing you're referring to this older picture of my engine bay I posted a while back. Yeah, I just left the EGR alone on the manifold. Since I'm not 100% certain what my long term plans are, as far as keeping the Weber vs. going back to stock, some things like this and the metal spaghetti monster between the carb and valve cover I've just left alone. I will probably start removing these sort of things over time but I'm not sure yet. I have also debated connecting the EGR with the Weber but I'm not sure if I have a good enough reason to do this yet. Thanks to the classic collector's insurance loophole for classic cars in Arizona, I've no worries about smog inspections any time soon.

Yes that makes sense about your vacuum port - referring to this same photo above, you can see I had my vacuum routing incorrect. I just got it fixed earlier today, with one vac line going from the intake to the vacuum advance, and a second separate vac line from the Weber to the vacuum advance.

Part of the reason I haven't posted in a while here though, other than being swamped with college, is that I've been battling a drivability issue with the Tercel for some time. I've got a bit of sputtering/backfire/hesitation under medium acceleration and I haven't seemed to crack the code just yet.
After getting my vacuum routing set up correctly earlier and taking a short test drive around the neighborhood, it feels better but the hesitation and sputter is still there under medium throttle, once I get into second gear. Unfortunately I haven't daily driven the Tercel for quite some time due to this.

I want to get to the bottom of it but my time has been quite limited. Next on my list is confirming proper ignition timing, then double checking that I've got a decent fuel mix setting at the carburetor.

This engine is not the stock 3A that came in the Tercel, but actually the 3A-SCV, a JDM variant with a "swirl control valve" on the back of the valve cover. After discussing with others on the Tercel forum I think that there may also be parts associated with this that could be malfunctioning, and causing my drivability issues, possibly. I have bypassed the valve, but there may be some moving parts associated with the SCV under the valve cover after seeing a picture of an SCV engine someone shared with me. I have yet to confirm this. I don't remember seeing this when I replaced my valve cover some time ago but who knows. Another thing to check for sure.

 

Now Ive gotta ask... Whats the insurance loophole?

 

If you (1) register your vehicle with a historic title, and (2) maintain collector's car insurance, you can be granted exemption from smog inspections in Maricopa county or any other counties requiring smog inspection. It is a bit of an unknown procedure - I knew more about the process than the person at the MVD I spoke to. Eventually they talked to their supervisor and I was granted exemption, and was able to register my Tercel for the next 5 years for ~$100.

Another little nugget of knowledge I learned from an older gentleman at a carb tuning shop here in Phoenix... holding collector's car insurance doesn't prevent you from also keeping traditional car insurance. If you plan to still daily drive your older car, this is key. Your collector's insurance company would laugh at you if you told them you got into a fender bender on the I-10 on a Wednesday morning. Having both insurances means you reap the benefits of no smogging and can still receive compensation should you need it while commuting. Your mileage may vary & I am by no means an expert on the matter, but this is what I've learned about the process thus far.

 

This is roughly what I was thinking, great information thanks for sharing. I know most collector insurance has some mileage clause but I imagine that null and void if you need to make a claim on the primary policy. Ive added old cars to mine which has actually bought my overall policy down.

This is one thing Maricopa does an OK job at.

 

Okay, I had a chunk of time today so I made some progress on the poor running situation.
Despite backing out & rotating the distributor a tooth to a few different locations, timing is still off and I cannot get the #1 spark plug to fire at 10deg BTDC. So it seems that my cam gear is off a tooth.
I also had bad spark plug wires. Earlier I saw the plug wires arcing across the top of the distributor - and I got zapped by them before I realized what was happening, when I tried to rotate the dizzy & set timing.
Ah well - lessons learned, I made it out unscathed, and $27 & a trip to Autozone later I've got new non-externally-arcing spark plug wires. This also definitely helps explain the erratic behavior and inconsistent running condition.

I don't have the Tercel running right just yet but I'm on the right track. Tomorrow I should be able to get it sorted out. Made a lot of progress today, and I learned a great deal after using my timing light and vacuum gauge to adjust running conditions.

 

She's alive!!!


After much frustration and further disassembly, I've got my Tercel back to good running order.
I removed the radiator, valve cover and upper timing cover in order to properly inspect and set ignition timing.
After a bit of frustration, I realized that a previous owner had chipped the crank pulley where the timing mark was meant to be, so after verifying I was indeed at TDC on the compression stroke, I added my own series of timing marks to the crank pulley.


Using the timing marks on the upper timing gear, and after removing the #1 spark plug and looking for the piston surface in the hole, I was able to ensure TDC on the compression stroke.


Once at this position, I rotated the distributor until the rotor pointed "northwest", towards the #1 spark plug.


After reassembling the Tercel, it fired right up and sounded much happier! I set the timing to 10 degrees BTDC, and then used my vacuum gauge to set a proper lean mixture at the Weber 32/36 carb. I was able to get 22 inHg of vacuum at idle which is fantastic!


I took the Tercel for a test drive, the first it has had since January (notice the layer of grime ). It drives GREAT! It's snappier and more responsive than it's ever been. No more throttle lag, hesitation, backfiring, sputter etc. and I am certain to see an increase in fuel economy. The spark plugs were coated in carbon deposits when I was inspecting them while setting timing. Based on the increased performance I see and feel after setting my timing and carb mixture, I'm certain that the car will burn its fuel more efficiently.
I am so very happy to have this back on the road, and I learned a great deal over the course of the past couple of days.

 

Back to daily driving the Tercel, and I'm loving it.
I'm pretty well caught up on maintenance, just have a few things to chip away at. As some of you have seen in my post about replacing lots of major suspension parts, the front brake rotors are looking pretty rough. Hopefully sooner than later I will get these rotors turned once more. Brake fluid needs flushed too.
I need to add another can of R12 to my AC system but it's still blowing reasonably cold for now (I don't have a freon leak, the manifold gauge I used when I initially filled my AC last summer was old and an o-ring blew out while I was filling the system).

When I was setting my timing and checking things over, I realized that my distributor cap and rotor are likely original parts.
It's not shown in the photo, but they are marked "ND", for NipponDenso, which was/is OEM for most of the electronics & associated components for Toyota. They just go by Denso now.

There's certainly nothing wrong with Denso parts, but I bring this up because these parts are surely ancient and deteriorating. Maybe this distributor cap still had life in it, but I didn't want to chance it.


The new one looks much better. If you look at the bottom two distributor cap posts, I also like that they are separated from the plastic housing, so I believe this distributor cap will give less problems as the posts wear down.


Nothing like new parts in the engine bay. Not a very exciting repair but a repair nonetheless. Initial impressions with the new parts are good. Throttle response/ignition seems improved, but likely just placebo.

Here's to many more miles with my wagon!

 

nice work! Setting timing on an older engine is a lost art

 

Thank you! I definitely agree, after going through this procedure and seeing what a difference it made, I feel a bit foolish not looking into this sooner. I am still learning a lot about how to maintain this old car, and things such as engine timing have just been out of my realm of experience so far.

Hopefully sooner than later, I'll get the valve cover back off and take a look at my valve clearance - another task that I have yet to learn. I'm sure it's been a minute since this engine has had its valves adjusted.

 

Cool project, love seeing it coming back to life.

 

Thank you! It has been a real pleasure slowly restoring this car. I had no idea what I was getting into when I bought it, or how much attention it would get. It makes me happy that others enjoy seeing this car kept alive.