Toyota carburetor problems

[Stephen Condict]

Does anyone else have this problem: 1987 Tercel, 60k mi.: 1.idle suddenly 200-300 rpm too high
3.engine does not return to idle as readily as before 3. mileage 15-20% worse than before.Thanks.

[Stephen Condict]

[Tina Rust]

Stephen Condict <stephen...@yale.edu> wrote:

>Does anyone else have this problem: 1987 Tercel, 60k mi.: 1.idle suddenly 200-300 rpm too high
>3.engine does not return to idle as readily as before 3. mileage 15-20% worse than before.Thanks.

I have a 1989 Tercel, 110k mi. and have had unending problems with the
carburetor since about 55k mi. Mainly, it won't idle at all after
initial startup. I have to rev the engine constantly at stops in the
morning to prevent stalling in traffic. Finally after about 5 mi. it
will warm up sufficiently to idle.

I've taken it to many different mechanics - the last one was a
carburetor specialist - they cleaned the carburetor thoroughly, said
the idle was too high and adjusted that, and had it running smoothly,
for about a day. Back to the same old routine.

This problem appears to be different from yours, Stephen - your car
idles too fast, mine won't idle at all until warm. Mechanics have
told me to expect carburetor problems with the late 1980s Tercels.
Any suggestions would be greatly appreciated. -Tina

[Ken Bell]

In article <319142EF...@cris.com>, George Bonser <gr...@cris.com> wrote:
>Could be that the EGR valve is working when the car is cold ... it
>should not be.

Also, what about the fuel vapor canister (evaporative emission control
system)? Assuming of course, that a Tercel has such a thing. If that's
allowing vapor into the carb when the car is cold, she'd have trouble
with idle; there is a 3 or 4 way valve on GM systems that is used to
avoid just this, and they sometimes fail (easy to test, cheap to replace).

--
Ken Bell :: ken...@panix.com :: (212) 475-4976 (voice)
======== :: sy...@giss.nasa.gov :: (212) 678-5516 (voice), 678-5552 (fax)

[-Bodnar,B.L.]

In article <4mr3k2$8...@harbour.awod.com>, Tina Rust <tr...@awod.com> wrote:
>Stephen Condict <stephen...@yale.edu> wrote:
>
>>Does anyone else have this problem: 1987 Tercel, 60k mi.: 1.idle suddenly 200-300 rpm too high
>>3.engine does not return to idle as readily as before 3. mileage 15-20% worse than before.Thanks.
>
>I have a 1989 Tercel, 110k mi. and have had unending problems with the
>carburetor since about 55k mi. Mainly, it won't idle at all after
>initial startup. I have to rev the engine constantly at stops in the
>morning to prevent stalling in traffic. Finally after about 5 mi. it
>will warm up sufficiently to idle.
>
>I've taken it to many different mechanics - the last one was a
>carburetor specialist - they cleaned the carburetor thoroughly, said
>the idle was too high and adjusted that, and had it running smoothly,
>for about a day. Back to the same old routine.
>
>This problem appears to be different from yours, Stephen - your car
>idles too fast, mine won't idle at all until warm. Mechanics have
>told me to expect carburetor problems with the late 1980s Tercels.
>Any suggestions would be greatly appreciated. -Tina
>

The *first* place I'd look at for warm idle problems on a carbureted engine
IS NOT the carburetor -- it's the heated air inlet. If cold air is coming in
when the carburetor expects warm air, icing will occur and drivability
problems like yours will certainly occur.

Regards,

Bohdan Bodnar

[David Burns]

>
>>Does anyone else have this problem: 1987 Tercel, 60k mi.: 1.idle suddenly
200-300 rpm too high
>>3.engine does not return to idle as readily as before 3. mileage 15-20% worse
than before.Thanks.
>
>I have a 1989 Tercel, 110k mi. and have had unending problems with the
>carburetor since about 55k mi. Mainly, it won't idle at all after
>initial startup. I have to rev the engine constantly at stops in the
>morning to prevent stalling in traffic. Finally after about 5 mi. it
>will warm up sufficiently to idle.
>
>

Could this be caused by a faulty EGR valve? These valves are supposed to
open up when the engine is warm and dump exhaust gas back into the intake
manifold. EGR stands for exhaust gas recirculation -- if the engine is cold
it will not burn the extra gases. I had a Toyota truck with a bad EGR valve.
It was open all the time and would idle unevenly at times.

Dave

[Rick Jones]

These things have a huge manual on them for drivability only
87-90, also a modification kits too, was yours done? Not that it seemed
to help.
Most common trouble is the air bleed located under the air cleaner
called EBCV or electronic bleed control valve..
Rick

[Mike Skinner]

In article <4ms3ce$l...@panix2.panix.com>, ken...@panix.com (Ken Bell) writes:
|> In article <319142EF...@cris.com>, George Bonser <gr...@cris.com> wrote:
|> >Could be that the EGR valve is working when the car is cold ... it
|> >should not be.
|>
|> Also, what about the fuel vapor canister (evaporative emission control
|> system)? Assuming of course, that a Tercel has such a thing. If that's
|> allowing vapor into the carb when the car is cold, she'd have trouble
|> with idle; there is a 3 or 4 way valve on GM systems that is used to
|> avoid just this, and they sometimes fail (easy to test, cheap to replace).
|>
|> >Tina Rust wrote:
|> >>

|> >> Stephen Condict <stephen...@yale.edu> wrote:
|> >>
|> >> >Does anyone else have this problem: 1987 Tercel, 60k mi.: 1.idle suddenly 200-300 rpm too high
|> >> >3.engine does not return to idle as readily as before 3. mileage 15-20% worse than before.Thanks.
|> >>
|> >> I have a 1989 Tercel, 110k mi. and have had unending problems with the
|> >> carburetor since about 55k mi. Mainly, it won't idle at all after
|> >> initial startup. I have to rev the engine constantly at stops in the
|> >> morning to prevent stalling in traffic. Finally after about 5 mi. it
|> >> will warm up sufficiently to idle.
|> >>

|> >> I've taken it to many different mechanics - the last one was a
|> >> carburetor specialist - they cleaned the carburetor thoroughly, said
|> >> the idle was too high and adjusted that, and had it running smoothly,
|> >> for about a day. Back to the same old routine.
|> >>
|> >> This problem appears to be different from yours, Stephen - your car
|> >> idles too fast, mine won't idle at all until warm. Mechanics have
|> >> told me to expect carburetor problems with the late 1980s Tercels.
|> >> Any suggestions would be greatly appreciated. -Tina
|>

|> --
|> Ken Bell :: ken...@panix.com :: (212) 475-4976 (voice)
|> ======== :: sy...@giss.nasa.gov :: (212) 678-5516 (voice), 678-5552 (fax)

All '87-90 Tercels have an infamous, poorly designed variable-venturi carb and
related
emissions control system which produce a variety of problem symptoms. I've had all
the above-mentioned ones, and worse, with my '88 Tercel. The most common
complaints are severe hesitation, dangerously poor acceleration, low power,
idle stalling, startup flooding, low or varying idle speed, stinky or
overheating catalytics, and sooty exhaust. The problems
have been widely publicized and discussed for years in this newsgroup, in the
Toyota mailing group, in books on 'lemon' cars, and in auto magazines.
Toyota held
a 'silent' recall on the problem while cars were still under warranty, issued
Technical Service Bulletins to Toyota dealerships, published a 'Tercel
Driveability Handbook' for awhile as a separate piece of service literature,
redesigned the carb once and the emissions system annually, produced a
'driveability field installation kit' workaround for awhile, but didn't really
cure the problem until '91, when Tercels all went F.I. Roughly 500,000 Tercels
were produced during this timeframe, and all of these are almost certain to
have carb problems of varying severity. The problems can start at any mileage,
but typically show up in the 60,000-80,000 mile range. The only solution is carb
replacement and head decarbonization, but there have been some claims that the new
replacement carbs sometimes seem to go bad very quickly or are bad coming
right from the carton. Numerous consumer
complaints have been filed with NTSC and with other consumer agencies,
but no federally mandated universal recall was issued because the problem
is not specifically safety related. Numerous lawsuits or threats of lawsuits
have been issued because of the problems, usually resulting in free carb
replacement for vehicles with expired warranties, or for cars within the
warranty period where a service facility claimed no carb replacement
was justified. Toyota service personnel have told me they sell a LOT of these
carbs, and that Toyota disallows their personnel from trying to repair or rebuild
faulty units, both because such adjustments/cleanings/rebuilds either don't
work at all or don't last long. Rebuilts seem to be unavailable and most
independent carb shops won't touch the unit.

The problem is that the fuel-metering needle or metering needle seat has
a thin teflon coating which erodes over time due to friction and gasoline
detergents, changing some critical fuel
metering dimensions, thereby causing progressively richer mixture,
which in turn causes a myriad of richness-related and carbon-deposit-buildup
related problems to eventually appear. There may also be lesser problems
associated with the EBCV control (part of the emissions system) and with the
idle compensator (a unique coolant-temperature-controlled thermostatic
choke function permanently attached to the side of the carb).

Mike Skinner
ski...@aur.alcatel.com

[Rick Jones]

Now for the answer to all these Tercel problems.
It is true as stated abve, all of it, but to get rid of this hesitation
you must remove the head, clean off the big gob of carbon off from back
side of the intake valve caused by leaking stem seals in the valves and
replace seal with the new updated parts.
This acts like a sponge and absorbs fuel and restricts flow.
You wont believe how much carbon is on these valve, and when its done,
you'll think someone put Nitrous in.
Rick Toyota Master/ASE Master/L-1

[rkarl...@gmail.com]

On Tuesday, May 7, 1996 at 12:00:00 AM UTC-7, Stephen Condict wrote:
> Does anyone else have this problem: 1987 Tercel, 60k mi.: 1.idle suddenly 200-300 rpm too high
> 3.engine does not return to idle as readily as before 3. mileage 15-20% worse than before.Thanks.

I have an 89 Tercel, 98000 km, Variable Venturi carb.... bought a few months ago. It sputtered between 80 to 90 kph, and had acceleration weakness. In the past I've worked on a lot of carburetors but never one of these. Good compression but spark plugs looked whitish... clearly running lean, this makes the engine run hot, and is hard on valves and everything else. I took it to different shops, no one could fix it and most didn't want to even try. I was going to put a Weber carb on it, when I thought I would try one more thing. Since this engine is running lean, I will disable all things on it, that make it run that way. When the engine is cold, its made to run "rich." As the car heats up, the computer then shifts to "lean" mode. This is when the trouble begins on my Tercel. First thing I did was unplug that silly electrical carburetor heater.... what the hell is the point of that thing anyway. I've worked on hundreds of carbs and never seen one of those before. Second was to unplug the vacuum lines of the BVSC and connect them up in the "permanent cold" position, thus preventing the carb from going to hot "lean" settings.
I couldn't believe it, car runs great now, hasn't sputtered on me for 2 months now. Plugs look better. I'll know more when I put in new plugs and check them after a couple months. Vacuum is fine. EGR works good... easy to test on this car... just leave it idle, place finger in bottom of EGR valve, reach over and rev engine... you can feel the EGR plate move if its ok. Next step, I'll take it to my mechanic and get an emissions test to check status. I bet its better than before. It barely passed previous inspections. My theory is that Toyota put all this "lean running" junk on it to pass Federal emmisions requirements. The fragile system falls out of spec after a few years, starts running dangerously lean, engine runs too hot, causing burnt out valve seals, stalling, and other issues.