What’s next here?

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FriendOfEvanW
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Posts: 28
Joined: Tue Jan 12, 2021 11:50 pm
My tercel:: 1984 Tercel DX Wagon 2WD
Location: Oregon

What’s next here?

Post by FriendOfEvanW »

I’m in the process of tuning up a 1984 Tercel DLX wagon my friend is letting me use for a few months. Given to me with an unstable idle, hard starts, dieseling on shutdown, overdue for oil change, no heat, no A/C, and no power steering.

-went in for a quick-e-lube oil change first thing; they claimed pan gasket was leaking too much to put oil in. Also added power steering fluid, but that basically poured out the bottom immediately. Not an urgent problem, has its own belt and it’s a Tercel so it’s not necessary

-appt. made for gasket job, in the meantime try to adjust carb as he says it seems rich. Find fuel pump spraying gas out as well as no gas cap. Replace those, idle still not ideal and hard to dial in carb adjust. Notice that temp gauge is way too low always.

-replace thermostat and coolant temp sensor; now the heat works and I have an accurate temp on gauge.

-changed oil; mechanic says pan gasket not likely. Points out leaky valve cover and timing belt cover gaskets. He also adjusted the timing as it was +15 and checked plugs (fouled and ancient).

-while being shown leaky gaskets I notice the PCV is loose enough to wiggle around and pull out easily, also the carb mount bolts are visibly loose

-replaced the PCV and grommet and tightened the carb mounts. Now idle is easily adjustable and stable (no tach, but sounds good)


That’s where I’m at. I think I’ve IDed the vacuum leaks that were messing with the mixture causing unstable idle and running lean constantly. Faulty CTS and thermostat hid the problem, and I believe running like that for months has fouled the plugs and likely carbonized the whole system good. Running hotter than normal with all that schmutz and nasty plugs is my guess as to the dieseling issue, and the bad mixture along with the fouled plugs could account for the hard starts. I’ll know for sure once I have new plugs in with my new fuel/air mixture.


I’ve got a fresh oil change, but haven’t installed the new plugs because I want to try and remove some of the crud first so I don’t just foul the new plugs.

What are your favorite ways to clear out after a period of neglect like this? Italian tune up? Seafoam deep soak? I haven’t worked on a carbureted engine since I was 11 so any tips are welcome.


Thanks!
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dlb
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My tercel:: '87 sr5, '83 dlx parts car
Location: bc, canada

Re: What’s next here?

Post by dlb »

Good work so far. The dieseling could have been caused by the timing being too far advanced too.

I have found that soaking things in seafoam didn't do much, if anything. I like to add it to the oil and run it for a tank of fuel and then change the oil. For cleaning combustion chambers, I use water in a spray bottle and squirt it in the air intake while the engine is running and rev it up a bit. I do this until the exhaust turns from filthy grey to white.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: What’s next here?

Post by Petros »

welcome, looks like you are doing some good work there. the unstable idle, and dieseling is typical of a a vac leak causing a lean mixture (too lean makes it run hotter too). you might check for other vac leaks in the many vac lines, easy with a can of carb cleaner or starter spray: squirt bursts of spray at various places around the carb and manifold, and all the vac lines. if the engine speeds up when you spray it at one spot, you found the location of the leak.

it is very unlikely the oil pan gasket will suddenly develop a leak, never trust ANYONE that tells you that. more commonly it is leaking from the valve cover gasket, or the half moon plug at the back of the valve cover, or o-ring round the distributor shaft, sometimes the oil sender or the water pump gasket. less common is the gear main seal. it can not leak out of the timing belt cover, there is no oil there (and no real gasket either), but it can leak from the front seal or the front cam seal, but that is rare. easiest way to located it to steam clean or pressure wash the engine off good, and than watch for the source of fresh oil as you drive it.

if the old plugs are not failing, likely any build up from improper mixture is already burned off. you can try the decarborizing it with a seafoam or gumout soak, sometimes that works well.

BTW, do not run the factory 5 deg BTDC spark timing, it can cause damage to the exhaust valves. it runs best, gets the best economy with spark timing at 10 to 12 Deg BTDC.

You might also go down load a copy of the factory service manual (found elsewhere on this site) and run through the sequence of carb adjustments and simple tests. it will only take about 15 to 20 min to do the adjustments and will make it run and start better.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
FriendOfEvanW
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Posts: 28
Joined: Tue Jan 12, 2021 11:50 pm
My tercel:: 1984 Tercel DX Wagon 2WD
Location: Oregon

Re: What’s next here?

Post by FriendOfEvanW »

I’ve already timed it by ear, just kept advancing until I heard pinging on hard acceleration then backed it off a bit. That plus new plugs, a full can of Seafoam in to the carb, and a tank of premium solved the dieseling.


Now my newest problem is a coolant leak that seems to be coming from the weep hole. I know this means the seals/bearings are ready to go so I have a new pump on order, but it won’t be here until Friday so I’m going to top it off and mark the tank every 10 miles or so to get a picture of how often I’ll need to stop and fill it again. I work 30 miles from home; so that commute is going to make it break it.


Quick question: if the coolant was overfilled would that excess pressure cause the weep hole to leak fluid? Or is it strictly bad bearings and seal that open it up?
FriendOfEvanW
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Posts: 28
Joined: Tue Jan 12, 2021 11:50 pm
My tercel:: 1984 Tercel DX Wagon 2WD
Location: Oregon

Re: What’s next here?

Post by FriendOfEvanW »

Also, the hard starts were just a result of me not knowing how to properly operate and adjust the aftermarket Weber carb. Got that figured out and it starts right up.
xirdneh
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My tercel:: 87 tercel 4x4 wagon w/reringed engine, 83 tercel 4x4 wagon w/salvaged engine and 4.1 Diff's
Location: seabeck, washington, USA

Re: What’s next here?

Post by xirdneh »

The tercel power steering requires automatic transmission fluid. Power steering fluid is not good for these cars.
Love those Tercell 4x4 wagons but they sure suffer from road noise.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
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Re: What’s next here?

Post by Petros »

there is no other reason for coolant leaking out of the weep hole in the water pump other than a leaky seal. either the seal is giving up, or the bearing is wobbly and allows coolant past the seal. if you rock the water pump pulley side to side, and detect any movement in the shaft, it is already bad. best replace it ASAP, because it could suddenly blow out all at once and will not hold any more water. fortunately changing the water pump is easy, it takes me about 30 min with just a few hand tools. Good luck.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
FriendOfEvanW
Member
Posts: 28
Joined: Tue Jan 12, 2021 11:50 pm
My tercel:: 1984 Tercel DX Wagon 2WD
Location: Oregon

Re: What’s next here?

Post by FriendOfEvanW »

xirdneh wrote: Sun Jan 24, 2021 9:56 am The tercel power steering requires automatic transmission fluid. Power steering fluid is not good for these cars.

I don’t think the previous owner knew that either, because when I filled it up with ATF it didn’t just pour out the bottom like before. It’s actually working now (good job Toyota, it ran dry for at least a year), although it’s got a pretty bad leak from the boot at the end. As far as I know the only fix is replacing the rack, so I’ve got it filled with ATF and Lucas Stopleak right now. I figure it can’t make it leak any more, so it’s worth a shot.
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Petros
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My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: What’s next here?

Post by Petros »

FriendOfEvanW wrote: Wed Jan 27, 2021 6:25 pm although it’s got a pretty bad leak from the boot at the end. As far as I know the only fix is replacing the rack, so I’ve got it filled with ATF and Lucas Stopleak right now. I figure it can’t make it leak any more, so it’s worth a shot.
you can replace the seals on the rack without having to remove it as I recall. not too bad a job. but if the stop leak works, no reason to not go with that until the seal needs to be replaced.

usually these power steering units and the racks are fairly durable, though I know of some that managed to trash their racks. I have never run mine dry, but both the rack and the power steering pump still work at 400,000 miles, no leaks. I keep it topped up. I do not think I have ever even changed out the ATF in it.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
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