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1986 Tercel 4x4 (3AC Engine)

Hello Everyone:

My Toyota started to lose horsepower and pickup over about a week period. It caught me in a surprise situation, so I was unable to get a diagnosis as the first symptom appeared.

It all started by the car not pulling uphill well. Instead of going uphill and holding 60 mph it was reduced to 45-50 mph. From there it was a continuous degradation of performance.

The only way I was able to get any RPM's out of it was to choke the carburetor by cupping my hands over it and gradually letting air in. After I was able to get RPM's, I had to hold them with the throttle, when the RPM's got bellow 2 thousand the engine seemed to delay when the pedal was applied quickly. When the gasoline pedal was floored the engine non-responsive and wanted to stall.

The Tercel, at idle, was very rough, sometimes it was possible to get the engine to rev when applying the gasoline pedal very slowly and smoothly. When driving the Tercel in this degraded state it would pull out of a complete stop on about half power, like I said, once over 2 thousand RPM's the engine appeared to have some pickup.

When removing the original carburetor I noticed that gasoline was puddling in the intake manifold, I cleaned the gasoline out and applied new mounting gaskets. Same symptoms.

I have tried a second carburetor from the junkyard and the same symptoms appear. With both carburetors the intake manifold was flooded.

Here is what I changed in hopes of fixing the ailment:

1) The majority of the vacuum hoses/tested all hoses 2) Carburetor/Mounting Gaskets

As of now, the Tercel does not want to start on its own.

An unofficial local mechanic checked the timing belt, which was apparently in good condition.

A second unofficial mechanic checked the spark of the spark plugs and said the spark was weak and suggested the coil in the distributor and to disassemble one of the carburetors and check the float level. I have not entered into either venture.

I would sure appreciate and helpful hints/suggestion/insight into this problem. I am unable to drive the Tercel to a shop and would prefer not to have it towed because of monetary reasons.

Thank You.

Reply to
Ken LaCroix
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Hello Everyone,

I have some new progress to report with my Tercel, It is not running yet, but I have been narrowing down the possible culprits.

The Carb sight glass is fine, the gasoline in the sight is about halfway up and down.

The car has new spark plugs and the spark also appears to be fine, all four plugs are firing, and the wires are known to be good.

The Tercel has now had three carbs on it, the most recent which is number three is known to be good, there is still pooling in the intake manifold.

I have done a compression check and the results are as follows:

Cylinder 1:

120 PSI normal and 150 PSI With a teaspoon of oil

Cylinder 2:

110 PSI normal and 150 with oil added

Cylinder 3: 120 PSI normal and 150 PSI with oil added

Cylinder 4: 100 PSI normal and 150 PSI with oil added

I have heard and read that if two consecutive cylinders have at least

20 PSI or more difference there may be a head gasket leak. Can this be the culprit or just a culprit?

Thanks again for anyone who is willing to help me solve this problem.

Reply to
Ken LaCroix

Start looking at something external to the carburetor, like the fuel line leading to the carb. The flared fitting may not be sealing and fuel is leaking and air is getting in. Leaking fuel could account for the pooling fuel in the intake manifold. When the engine is running, if you look down the venturi, is the fuel atomizing or is it dribbling?

A head gasket leak would not cause fuel to pool in the intake manifold. Cylinder 4's compression is low but probably not worth trying to remedy on a car that is close to 20 years old.

Reply to
Ray O

Son of a gun, I just scrapped one of these a couple months ago! I would have GIVEN it to you; it had a great engine...

Reply to
Hachiroku

I have taken a few pictures of the Carb assembly and have recorded the sound of the engine, if it helps. Here it is:

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Reply to
Ken LaCroix

I don't remember... Does this car have a mechanical or an electric fuel pump?

What is the brown stuff all over the stuff around the carb? Did the engine overheat?

Is the mounting plate on the intake still a flat plane?

Reply to
Ray O

A mechanical fuel pump, and when I checked it awhile ago it was fine.

This carb came from Minnesota, and they use salt on their roads, so thats rust.

No the engine never over heated.

Yes, the mounting plate is flat.

Thanks Ray for the help you have given me so far, its appreciated,

Reply to
Ken LaCroix

This was a really long shot, but since the carb and intake were on the side of the block and if the mechanical fuel pump's diaphram or case was leaking somehow, I thought it might somehow get into the intake.

I wasn't sure if the brown was rust or residue from an overheated engine or radiator that sprayed all over the place.

Again, this was a really long shot, but if the engine overheated, then the mounting plate for the intake might have warped, allowing even a good mounting gasket to leak. If it was sucking air, that would account for the need to "choke" the carb to make it run.

Just for grins, it might be worthwhile borrowing or buying a vacuum gauge to make sure you don't have a vacuum leak from some off-the wall place, like a vacuum switching valve. You should have in the vicinity of 18 in.hg. at idle.

Don't thank me yet - I haven't fixed your car yet!

Reply to
Ray O

Man, this is turning into quite the project.......

I dont think I know anyone with a vacuum gauge, and they are pretty expensive I have been told.

But anyway, It looks like the timing is up to specs, it has a known-to-be-good carb on it, new mounting gaskets, the cyl compression also looks to be in specs, I just cant imagine what else is could be.

Could it be the distributor? It would be odd that the distrbutor is sending electricity to all the plugs, but have some internal defect, is that possible? What part(s) could be defecting? If they where.

If anybody has any other suggestions, I am all ears.

Thanks

-Ken

Reply to
Ken LaCroix

Does it start and run OK? After I did a tune up on mine, it ran like shit! (I used aftermarket wires, BTW)

What it was, was a short, large tube under the air cleaner that came off when I replaced the air cleaner. After I replaced the hose we were up and running just fine again...

Reply to
Hachiroku

You should be able to get a Mighty-Vac for under $40. Some auto parts stores rent tools, you might want to check into rental.

Basically, 2 things go wrong with distributors: They don't send spark to the plugs or the O-ring leaks and you get oil in the distributor, which can prevent them from sending spark to the plugs. I can't think of any way that a bad distributor would cause raw gas to pool in the intake manifold.

By the way, Toyotas seem to run better when using genuine Toyota ignition parts, including cap, rotor, wires, and plugs.

Reply to
Ray O

Everyone:

I have solved the problem!

It appears that the timing belt had slipped two notches.

The crankshaft pulley was aligned with the first triangle, not the middle triangle. I fixed that and it started right up.

What is a mystery to me is how there was a gradual loss of power until it completely quite running. I wonder if there was a carb problem that caused the engine to run low on HP, and while attempted to drive the car in low RPMs caused the timing belt to slip?

Should I change the timing belt? Being that it slipped two notches, can it be stretched?

Thanks,

-Ken

Reply to
Ken LaCroix

I would. THis is an interference engine! You're kinda lucky it's still running.

Hey if ya wanna sell it...I miss my '83. I painted it BRIGHT YELLOW!! since I drove it a lot at night in the winter.

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Yellow Topaz, except I added a Pearl Coat top coat. Boy was it BRIGHT!!!

Reply to
Hachiroku

Nah, I don't have any plans to sell it at the moment, but I may at a later date.

But, what the heck where you doing driving around at night in the snow?

Reply to
Ken LaCroix

Work, and I play in a band.

Plenty of traction with my amp and speakers in the rear!!!

We had a weekly gig every Thursday night, and it just so happened it snowed a lot of Thursdays!

We couldn't cancel, so off we went!

That car was amazing! I NEVER got stuck!

But, I had the manual 4WD selector, a lever on the console to shift the linkage by hand. If you saw the pavement was clearing and DIDN'T switch out of 4WD before hitting the dry pavement, God help you! It would stick and the car would squirm like hell.

But it was reliable and comfortable, and handled nicely.

Reply to
Hachiroku

Yea, its funny you should mention the 4WD and dry pavement. Thats how I got the car so cheap. The dealer thought it was stuck in 4WD and he couldnt figure out how to get it out. Luckfully my Dad actually had one of these cars back in 80 something. We took it for a test drive and he was able to get it out.

But that Tercel runs awsome, like you say, on the snow, its like a little "snow speeder". Its fun trying to use all six gears while in

4WD, going from EL to 1st.

I actually can't wait for it to snow, just because its so fun driving it.

What kind of music to you make?

Reply to
Ken LaCroix

Wasn't a Toyota dealer was it? Some of the guys that were working where I was knew a Toyota was a car, and that was about it!

I only used EL when necessary...it was an '83 and I got it three years ago, so it wasn't *quite* 'primo*, but it did run very well after minor work and redoing the body.

Green Day, AudioSlave, Alice in Chains, and a bunch of others. We like playing newer stuff, and the guys I play with on Thursday nights just play for fun, so we play whatever *we* like. The band that plays out plays similar things, but we find 'oldies' (and the older the better, it seems) go over better in the bars!

Reply to
Hachiroku

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