YACT: Holy Hell in a handbasket. Update: Compression check done. Results; Dismal. Update: Engine is alive.

[Eli]

So... I own the venerable 1990 Toyota Tercel. They're OK cars.. bottom of the barrel econoboxes. Good MPG is about the only thing good about them.

The stock, 1 barrel, variable venturi, half-computer controlled catastrophe that Toyota(Actually, it was made by Aisan) called a carburetor had been giving me problems for a while, so I decided to replace it with an upgrade; A double barrel Weber 32/36 DGEV.

Installation was relatively straight forward... Remove old carb, remove all unnecessary vacuum lines, hoses, switches and check valves, and bolt on new carb. Install vacuum advance, PCV, etc. Install choke wire. Loop old carb's water choke lines... Probably the hardest part was getting the stock throttle cable bracket to work, which amounted to drilling a new bolt hole in the bracket. Also installed an adjustable fuel pressure regulator, since the Weber doesn't like over 3.0PSI and the stock fuel pump puts out 4.0PSI.

Old carb off

New carb on

It started right up and ran great, only required a little bit of idle adjustment to get it running smooth with good throttle response.

I also changed the plugs, which were pretty bad after only 10,000 miles.

All of the models with the 3E(E) engines suffer from a chronic problem; after a while the valve stem seals get hard and no longer seal anymore, causing the engine to smoke like a freight train.

It's only bad under certain conditions. Prolonged idling or engine braking down a hill allows the oil to "load up", and when you step on the gas again - poof - big cloud of blue smoke. It isn't noticeable while cruising the highway, though.

My plugs fouling after only 10,000 miles sucked, so I decided to get plugs two heat ranges hotter than the stock specified ones.

This turned out to be a huge mistake, the magnitude of which I don't quite know yet and frankly am a little afraid to find out.

I was cruising along at 90, tailing this nice Mustang GT(speed limit was 70). As some of you probably know, 90 in a Tercel is pretty much top speed. With the new carburetor, I should have about 86HP(The carb adds about 10 over stock). It doesn't have a tach, but I'd estimate it to be around 5,000RPM @ 90.

Suddenly, I lost power.. could barely keep it at 60. Fortunately, as this was occurring, I was comming to a rest stop exit, so I pulled off. The engine would idle, but very rough.. was only running on 3 cylinders.

I got my tools out and checked things out as best as I could.. I took the distributor cap off and examined it.. all cylinders appeared to be getting spark. I couldn't figure it out, so I drove the rest of the way home on 3 cylinders, about 100 miles. Ouch.

I suspected that it could be something to do with the plugs while I was checking things out, but for some stupid reason I didn't have a spark plug socket on me. :frown:

When I investigated further, what I found both shocked and horrified me. I've only pulled one plug out, and I'm afraid to even look at the others.

Spark plug from Cylinder #1

:shocked::frown::brokenheart::Q

What do you think the chances are that the practically missing center electrode made it out the exhaust port with the pistons traveling at 47.572 feet per second?

Another shot

::head desk::

Update: Well, I examined the rest of the plugs and ran a compression test. The results are dismal.

Plug #2 was the same as plug #1. Plugs #3 and #4 were OK, although the ceramic was white so they were getting too hot.

Cylinder #1: 65PSI
Cylinder #2: 45PSI
Cylinder #3: 165PSI
Cylinder #4: 160PSI

:shocked:

RIP Toyota 3E engine. :heart:

Actually, believe it or not.. it still drives OK. It does idle like sh!t, but it still has more power than it did with the stock(but malfunctioning) carburetor :laugh:

It seems that cylinders #1 and #2 run much hotter than #3 and #4. Could be intake manifold design. Do you think it's possible that they designed these two cylinders to run lean on purpose, because those two cylinders are the two closest to the EGR port? I didn't hook it back up, figured it was worthless emissions crap. It would help lower combustion chamber temperatures while "cruising", but I'm pretty sure the EGR is closed during WOT.

Those two plugs got so hot, the metal casing has a blue tint to it! :Q Holy sh!t.

It probably ran away. Since I was going so fast, I couldn't hear any preignition. As soon as the ground electrodes started glowing, I'm sure the cylinders started preigniting, increasing overall heat... I bet the first time I let off the throttle, the rich mixture cooled the plugs off quickly and shattered the center ceramic.

LOL.. Man. I guess I'll be getting a new head sooner than I thought. I'm going to assume that the valves in those two cylinders are toastier than toast itself. If I'm lucky.

If I'm not lucky, ceramic pieces lodged between the piston and cylinder walls meaning engine rebuild time! YAY!

I left the two plugs that were OK in the engine, and richened it back up.. I'll drive it for a while, and see if the plugs are still white as a ghost. If they are, I'll know that the heat range was definitely a factor.

The engine runs noticably cooler with two practically dead cylinders though, so it might not be a fair test.

Overall, I'm fairly upset at myself, because to me this is akin to someone killing an engine because they haven't checked the oil in a year. Stupid. I should have been more careful.

Update2: It sat around for a while, but I've got a job lined up now.. so I began to work on it the last few days.

Pulled the head off to check things out and for core exchange. Have Cylinder Head Specialists here in Portland building me a new one. These guys know their stuff, and their machine shop is immaculate. I went with them mostly because of their 1 year, 12,000 mile warranty, but after seeing their operation and talking to some folks, I was even more impressed. New valves, springs.. 3 angle valve job, viton valve stem seals.. Engine could be good for another 150,000 miles.

Anyway.. The cylinders look OK, so fortunately none of the shattered spark plug ceramic tore anything up. Amazing, considering I was spinning an estimated 5,000RPM when the head gasket blew and gave my sparkplugs a nice cool bath.

The exhaust valves were indeed toasty, though. :Q I'm thinking that even the main jet in my carburetor is too lean.. I'm going to have to richen the idle mixture up and drive it gently until I can look into it, especially considering my new job will involve driving about 140 miles a day.

Here are some pics.. Nothing really much to see, but hey.. pics are good.

Engine pr0n

Toasty exhaust valves :Q

Obviously the two cylinders on the left were the leaky ones.

My sparkplug just saw a ghost. :Q

Cam looks good, at least.. bit of varnish is all. No scoring, pitting or burning visible.

Although none of that really matters since I'm not having this head rebuilt..


Update3:

Well, I got the remanufactured head on.

pic of head

It started right up and seems to run great. I let it warm up and took it for a quick spin. Letting it cool off now, then I'm going to look at the plugs and check the compression just for reference.

I sure do hope it ends up being reliable. I'm driving 150 miles a day for work now.

Compression check is in:

Cylinder #1: 160PSI
Cylinder #2: 160PSI
Cylinder #3: 160PSI
Cylinder #4: 165PSI

wewt.

Plug porcelain is still white though. Damnit. I'm not sure what to do. I don't want to drive it lean. I took it for a few runs, both WOT and never going past 2/3rds.. and yeah, still lean.

I can get it very rich while idling, but it doesn't appear that the idle jet affects anything past... idle. Even cruising in 4th at 35mph and my plugs were still white. Damn.

I'm going to check and double check for intake manifold leaks, but this sucks.

 

[jhayx7]

Ouch!

I guess you didn't hear any funny noise coming from the engine?

Just disconnect the opposite spark plug and everything will even out

Just don't turn on the AC.

 

[Greenman]

That ain't good. That electrode if prolly stuck in the top of the piston, unless it went all the way through.

 

[Eli]

Oh.

Another part of the story is that I leaned the carburetor out slightly before the trip, hoping that it would improve my MPG a little. It only seemed to affect drivability when cold, so I didn't think I was doing any harm, but it could have easily contributed to the problem.

Damn. I'm going to take the other plugs out and do a compression check.. *cowers*

 

[sierrita]

It probably melted, rather than falling off as a "chunk".

Look at the spark plug analysis photos in a haynes/chilton's/etc., they always show the burned off electrode in one of them.

Not great, but not a major disaster, hopefully.


If you're lucky, anyway....

 

[tasmanian]

Umm...

 

[Eli]

Originally posted by: sierrita
It probably melted, rather than falling off as a "chunk".

Look at the spark plug analysis photos in a haynes/chilton's/etc., they always show the burned off electrode in one of them.

Not great, but not a major disaster, either.

Most of the center electrode, including the ceramic, is gone. Ceramic doesn't melt at temperatures seen inside an engine AFAIK. It broke probably because of heat stress. There were definitely pieces of foreign material floating around in at least 1 cylinder.

Originally posted by: tasmanian
Umm...

Are you confused? Was I not clear enough?

 

[sierrita]

Originally posted by: Eli

Originally posted by: sierrita
It probably melted, rather than falling off as a "chunk".

Look at the spark plug analysis photos in a haynes/chilton's/etc., they always show the burned off electrode in one of them.

Not great, but not a major disaster, either.

Most of the center electrode, including the ceramic, is gone. Ceramic doesn't melt at temperatures seen inside an engine AFAIK. It broke probably because of heat stress. There were definitely pieces of foreign material floating around in at least 1 cylinder.







I didn't notice the extent of porcelain missing...you're right...my bad... nightmare.

 

[Eli]

Originally posted by: sierrita
I didn't notice the extent of porcelain missing...you're right...my bad... nightmare.

Yeah, I rearranged the pics... it was kinda hard to get a good perspective with the 1st pic, without seeing the 2nd.

 

[sierrita]

Originally posted by: Eli

Originally posted by: sierrita
I didn't notice the extent of porcelain missing...you're right...my bad... nightmare.

Yeah, I rearranged the pics... it was kinda hard to get a good perspective with the 1st pic, without seeing the 2nd.

So what's next? Replace the plugs and see how it runs? It did get you home on 3, and the damage (to whatever extent) is already done.

Or do you pop off the head and get a look inside...meanwhile replacing those stem seals?

edit: I see you mentioned compression check, that's always a good place to start.

 

[Agentbolt]

If you've lead a good, clean life the electrodes will have melted instead of falling off in a big chunk into your pistons. I'm pullin' for ya.

At least you had the stones to post it here for our amusement. It's always great to be able to laugh at your own stupidity. Of course, this is coming from someone who destroyed a 1500 dollar computer less than a month ago because he was swinging it around like a retarded Little Red Riding Hood swinging around her basket for granny.

Anyways, lesson learned, right?

edit: Oops, I missed the second picture as well. Yeah, there's a big chunk of ceramic in there, that doesn't melt at any temperature you're going to find inside an engine. Sorry bro The pieces are gonna crunch up and chew up your seals. You could always sell it before disaster strikes.

For Sale: 1990 Toyota Tercel. New spark plugs!!

Then again, Toyotas made between about 1985-1994 are pretty much indestructible. Someone called into Car Talk one time trying to get ideas for how to make the car die so she could feel okay about getting a new one. Ray suggested draining the oil, to which the caller immediately replied "Oh, I did that months ago" Those cars are BEASTS.

 

[BUTCH1]

Try a new set of plugs and see what happens, and your driving habits are going to have to change.
Your car is now 17 years old and must be driven in a more moderate fashion if you wish to continue
driving it..Also it's not uncommon for ANY 17 year old engine to have problems with valve stem seals.
The GT @ 90 was barely breaking a sweat while your ride was @ warp 9 on the edge of a warp core
meltdown, just drive it as intended and enjoy the MPG as gas gets insane again. Installing a great stereo
is a good diversion, I did that when I had my Escort, it helped....

 

[Zenmervolt]

Wow, Eli, you're usually more with it than that as far as engines are concerned.

Learned though, didn't you.

THe problem was almost certainly running it that lean at 90 mph for a long time. You're lucky you didn't melt through a piston or burn a valve running it lean.

ZV

 

[Eli]

Originally posted by: sierrita

Originally posted by: Eli

Originally posted by: sierrita
I didn't notice the extent of porcelain missing...you're right...my bad... nightmare.

Yeah, I rearranged the pics... it was kinda hard to get a good perspective with the 1st pic, without seeing the 2nd.

So what's next? Replace the plugs and see how it runs? It did get you home on 3, and the damage (to whatever extent) is already done.

Or do you pop off the head and get a look inside...meanwhile replacing those stem seals?

Yup. I still have the old plugs, I'm going to clean them up a little and pop them in - and drive to the auto parts store.

It did get me home on 3 cylinders, so the damage, if any, probably isn't completely disabling.. Still sucks, though. A compression check should tell me more.

I've been planning on putting a remanufactured head on it, as I don't think it will be able to pass DEQ in about 4 months.

I'm feeling like I should just start putting together a whole new engine at this point. But what the hell is the point? The car is only worth like $1,500.. lol

I could put a 4E-FTE turbocharged engine into the car, making 135HP, which would make the 2,100lb Tercel pretty fun to drive.. but.. WHY? lol

 

[Specop 007]

Originally posted by: Eli
Another part of the story is that I leaned the carburetor out slightly before the trip, hoping that it would improve my MPG a little.

I think I found your initial problem.
Running engines lean and hard is a really bad idea.

But I dont suppose we need to tell you that now

 

[Eli]

Originally posted by: Zenmervolt
Wow, Eli, you're usually more with it than that as far as engines are concerned.

Learned though, didn't you.

THe problem was almost certainly running it that lean at 90 mph for a long time. You're lucky you didn't melt through a piston or burn a valve running it lean.

ZV

You think the leanness contributed more than plugs being "too hot"?

The only air:fuel mixture adjustment on the Weber is the idle circuit. The main jets are fixed(you have to change them to change the setting).

I'll have to reference my book, I'm not sure if the idle jets still meter at full throttle or not.

It is obvious that the jetting is a little lean, though. I have to have the idle screw out about 2.5 turns, which is the limit. Any more than that, and you're supposed to re-jet. I adjusted it about 1/8 a turn in. It didn't seem to affect the O2 sensor reading, but that was just at idle.. I should run it's wire into the cabin and install an A/F ratio gauge... lol

 

[BUTCH1]

Originally posted by: Eli

Originally posted by: sierrita

Originally posted by: Eli

Originally posted by: sierrita
I didn't notice the extent of porcelain missing...you're right...my bad... nightmare.

Yeah, I rearranged the pics... it was kinda hard to get a good perspective with the 1st pic, without seeing the 2nd.

So what's next? Replace the plugs and see how it runs? It did get you home on 3, and the damage (to whatever extent) is already done.

Or do you pop off the head and get a look inside...meanwhile replacing those stem seals?

Yup. I still have the old plugs, I'm going to clean them up a little and pop them in - and drive to the auto parts store.

It did get me home on 3 cylinders, so the damage, if any, probably isn't completely disabling.. Still sucks, though. A compression check should tell me more.

I've been planning on putting a remanufactured head on it, as I don't think it will be able to pass DEQ in about 4 months.

I'm feeling like I should just start putting together a whole new engine at this point. But what the hell is the point? The car is only worth like $1,500.. lol

I could put a 4E-FTE turbocharged engine into the car, making 135HP, which would make the 2,100lb Tercel pretty fun to drive.. but.. WHY? lol

I had to replace the head on my Escort@155K mi., the valve seat fell off and into the #4 cylinder, sounded like a food processor with
lug nut in it. Quite a long job as I had to replace the #4 piston as well. The carb install looked nicely done but let's face it Eli,
your gonna need a bigger boat...

 

[Eli]

Originally posted by: Specop 007

Originally posted by: Eli
Another part of the story is that I leaned the carburetor out slightly before the trip, hoping that it would improve my MPG a little.

I think I found your initial problem.
Running engines lean and hard is a really bad idea.

But I dont suppose we need to tell you that now

I know.. I'm well aware, I just didn't think it was that lean. It was probably a combination.. the plugs I got are the hottest available. Oops.

 

[Eli]

Well, I examined the rest of the plugs and ran a compression test. The results are dismal.

Plug #2 was the same as plug #1. Plugs #3 and #4 were OK, although the ceramic was white so they were getting too hot.

Cylinder #1: 65PSI
Cylinder #2: 45PSI
Cylinder #3: 165PSI
Cylinder #4: 160PSI

:shocked:

RIP Toyota 3E engine. :heart:

Actually, believe it or not.. it still drives OK. It does idle like sh!t, but it still has more power than it did with the stock(but malfunctioning) carburetor :laugh:

It seems that cylinders #1 and #2 run much hotter than #3 and #4. Could be intake manifold design. Do you think it's possible that they designed these two cylinders to run lean on purpose, because those two cylinders are the two closest to the EGR port? I didn't hook it back up, figured it was worthless emissions crap. It would help lower combustion chamber temperatures while "cruising", but I'm pretty sure the EGR is closed during WOT.

Those two plugs got so hot, the metal casing has a blue tint to it! :Q Holy sh!t.

It probably ran away. Since I was going so fast, I couldn't hear any preignition. As soon as the ground electrodes started glowing, I'm sure the cylinders started preigniting, increasing overall heat... I bet the first time I let off the throttle, the rich mixture cooled the plugs off quickly and shattered the center ceramic.

LOL.. Man. I guess I'll be getting a new head sooner than I thought. I'm going to assume that the valves in those two cylinders are toastier than toast itself. If I'm lucky.

If I'm not lucky, ceramic pieces lodged between the piston and cylinder walls meaning engine rebuild time! YAY!

I left the two plugs that were OK in the engine, and richened it back up.. I'll drive it for a while, and see if the plugs are still white as a ghost. If they are, I'll know that the heat range was definitely a factor. I really don't think it was that lean, but I really wish I would have checked the plugs out before going out of town.

The engine runs noticably cooler with two practically dead cylinders though, so it might not be a fair test.

 

[iamaelephant]

Hhhmm I don't want to sound like a wanker but I LOL'd at the first spark plug picture...

 

[Eli]

Originally posted by: iamaelephant
Hhhmm I don't want to sound like a wanker but I LOL'd at the first spark plug picture...

So did I, and I'm the one that pulled it out of my engine. :Q



lol

 

[iamaelephant]

Originally posted by: Eli

Originally posted by: Zenmervolt
Wow, Eli, you're usually more with it than that as far as engines are concerned.

Learned though, didn't you.

THe problem was almost certainly running it that lean at 90 mph for a long time. You're lucky you didn't melt through a piston or burn a valve running it lean.

ZV

You think the leanness contributed more than plugs being "too hot"?

The only air:fuel mixture adjustment on the Weber is the idle circuit. The main jets are fixed(you have to change them to change the setting).

I'll have to reference my book, I'm not sure if the idle jets still meter at full throttle or not.

It is obvious that the jetting is a little lean, though. I have to have the idle screw out about 2.5 turns, which is the limit. Any more than that, and you're supposed to re-jet. I adjusted it about 1/8 a turn in. It didn't seem to affect the O2 sensor reading, but that was just at idle.. I should run it's wire into the cabin and install an A/F ratio gauge... lol

It's doubtful that higher heat-range plugs would cause such a meltdown, I'm inclined to agree that the lean carb is more likely. What throttle position were you at on that highway at 90? If you were cruising at close to closed throttle then the cruise circuit of the carb would be pulling a fair amount of fuel from the idle jets, and if you leaned them out too far it could cause the engine to run lean.

Even that seems unlikely in my opinion though. Are you sure there wasn't a blockage in the carb? How long had you been cruising at 90? It takes times for an engine to get that hot unless it is really quite lean. I assume the cooling system was in good condition before the carb switch?

 

[Eli]

Originally posted by: iamaelephant

Originally posted by: Eli

Originally posted by: Zenmervolt
Wow, Eli, you're usually more with it than that as far as engines are concerned.

Learned though, didn't you.

THe problem was almost certainly running it that lean at 90 mph for a long time. You're lucky you didn't melt through a piston or burn a valve running it lean.

ZV

You think the leanness contributed more than plugs being "too hot"?

The only air:fuel mixture adjustment on the Weber is the idle circuit. The main jets are fixed(you have to change them to change the setting).

I'll have to reference my book, I'm not sure if the idle jets still meter at full throttle or not.

It is obvious that the jetting is a little lean, though. I have to have the idle screw out about 2.5 turns, which is the limit. Any more than that, and you're supposed to re-jet. I adjusted it about 1/8 a turn in. It didn't seem to affect the O2 sensor reading, but that was just at idle.. I should run it's wire into the cabin and install an A/F ratio gauge... lol

It's doubtful that higher heat-range plugs would cause such a meltdown, I'm inclined to agree that the lean carb is more likely. What throttle position were you at on that highway at 90? If you were cruising at close to closed throttle then the cruise circuit of the carb would be pulling a fair amount of fuel from the idle jets, and if you leaned them out too far it could cause the engine to run lean.

Even that seems unlikely in my opinion though. Are you sure there wasn't a blockage in the carb? How long had you been cruising at 90? It takes times for an engine to get that hot unless it is really quite lean. I assume the cooling system was in good condition before the carb switch?

Top speed, wide open, full tilt, secondary 100% open. I wasn't gaining any appreciable speed anymore. I followed the GT for at least 2-3 miles.. but it could have been more like 5-6, I wasn't paying much attention overall.

Along with the carburetor work I replaced the radiator and thermostat, the cooling system was in top order. As soon as I noticed the power loss, my first instinct was to look all over the gauge cluster, but everything was nominal. I thought maybe my oil filter popped off or something at first.

Nah. Was just my valves succumbing to the heat. Losing the oil filter would've probably been better.. LOL.

I think I was wrong, the plugs I got are three heat ranges hotter than the stock plugs.

NGK uses a number from 1 to 10 to define heat range. 10 = coldest and 1 = hottest.

Stock plugs are a "5". They had "4" and "2" in stock. I thought 4 would probably be too close to stock to make any appreciable difference, so I went with "2".

Dunno....

 

[iamaelephant]

Hhmm well then it certainly wasn't the idle circuit. I wouldn't have thought plugs a couple of heat ranges up could be so disastrous, but I suppose you thought the same thing when you put them in there Better you than me I guess!

 

[Eli]

Originally posted by: iamaelephant
Hhmm well then it certainly wasn't the idle circuit. I wouldn't have thought plugs a couple of heat ranges up could be so disastrous, but I suppose you thought the same thing when you put them in there Better you than me I guess!

The idle jetting being slightly lean could mean that the high speed circuit is also lean. I don't know. I should have done more proper testing, especially in light of changing the plug type.

The Weber carburetor is a conversion kit. The kits are put together by some company, can't remember the name off hand. It's very likely that they jet the carburetors slightly lean in the interest of fuel economy or simply because they didn't do thorough enough testing.