Civic '92 throttle response delay, bad idle

Kerozin wrote:
>> bingo! never use liquid gasket dude - this a textbook example of why!
>> either make a new gasket out of an old envelope [if you're desperate] or
>> buy the real deal.
>
> Actually that was a work of professional. It's quite hard to obtain
> parts for older Hondas here in Croatia so improvisation is quite
> common even for dealership workshops.

understand. you can buy parts online from the usa though. if they
won't sell you, i expect one of us can buy and ship to you instead.

> By the manual there should go O-
> ring which is of course not there so I'll have to use liquid gasket
> again.

not ideal, but if you have to, this time let it fully cure before
reassembly. otherwise it'll just squeeze out and block things again.

>
>> probably diode protected, but don't worry about that - just worry about
>> whether it clicks and opens when the correct polarity is applied. and
>> don't worry any more about taking it off - you've found your problem.
>> unplug the ports and everything will now work.
>
> I've just checked and plugged port is actually used by MAP sensor.

it's a while since i've taken one of these apart, but the tandem
solenoid /definitely/ gets its vacuum from low in the throttle body, not
high where the vent pipe goes. i'll check and reconfirm from the manual
when i get home.

> Unless ECU won't open tandem without high vacuum reading from MAP
> sensor

didn't know that, but it makes sense.

> I would still presume dead solenoid.

no, presume it's not getting signal if the map sensor venturi is blocked.

> i just hope it's working
> since I butchered old one really really bad. It's made from one piece
> of injected plastic, had to use dremel tool to take it apart.

between the two bodies you have, you should be able to assemble one
complete unit that works.

>
> I'll put tomorrow everything back together and let you know if problem
> is fixed. Thanks again, without your help I couldn't do a thing.
>

> it's a while since i've taken one of these apart, but the tandem
> solenoid /definitely/ gets its vacuum from low in the throttle body, not
> high where the vent pipe goes. i'll check and reconfirm from the manual
> when i get home.

Bad luck. Both solenoids from "new" and old TB are blown. I'm right
now trying to repair one of them but it'll be really hard to do so.

Btw, tandem vacuum port is actually between two plates, right in the
level with solenoid.

This is what I have to put back together:
http://kerozin.dyndns.org/DSC00877.jpg

Another bad thing is that I'm reading unusually high voltage on ECU
side of solenoid plug. It's over 17 volts and once engine is fully
warmed it's constantly there regardless RPM. Blown ECU would really
really depress me.

I'm gluing with araldite epoxy one of solenoids, so tomorrow after
soldering back coil and diode we'll have another try.

Kerozin wrote:
>> it's a while since i've taken one of these apart, but the tandem
>> solenoid /definitely/ gets its vacuum from low in the throttle body, not
>> high where the vent pipe goes. i'll check and reconfirm from the manual
>> when i get home.
>
> Bad luck. Both solenoids from "new" and old TB are blown. I'm right
> now trying to repair one of them but it'll be really hard to do so.
>
> Btw, tandem vacuum port is actually between two plates, right in the
> level with solenoid.
>
> This is what I have to put back together:
> http://kerozin.dyndns.org/DSC00877.jpg

slight problem!

>
> Another bad thing is that I'm reading unusually high voltage on ECU
> side of solenoid plug. It's over 17 volts and once engine is fully
> warmed it's constantly there regardless RPM. Blown ECU would really
> really depress me.

it's hard to see how you can get 17v on a nominally 12v system. and
it's /highly/ unusual [but frequently misdiagnosed] for an ecu to die.

>
> I'm gluing with araldite epoxy one of solenoids, so tomorrow after
> soldering back coil and diode we'll have another try.
>

you may save yourself the time and effort by just getting another
throttle body. even if you get that thing back together, it'll be
highly suspect. shouldn't really disassemble a solenoid, just replace.n
only reason to try repair is if parts are otherwise absolutely
unavailable.

> you may save yourself the time and effort by just getting another
> throttle body. even if you get that thing back together, it'll be
> highly suspect. shouldn't really disassemble a solenoid, just replace.n
> only reason to try repair is if parts are otherwise absolutely
> unavailable.

Well to be honest I quite enjoyed it despite hours of time wasted.

And guess what - IT WORKS! This is finished product:
http://kerozin.dyndns.org/DSC00878.jpg

I glued the thing back together, threw in 1N4005 diode for coil surge
protection (since I couldn't find old one in solenoid) and tandem is
now working. I'll have to get new solenoid since this one will fail
for sure after some time since it's no longer watertight and I have
doubts how well it holds vacuum.

The question is why two solenoids failed, wouldn't be surprised that
something is blowing them. We'll see over period of few days.

And the car is so much faster now - manual tranny, everything stock
minus rear seats, spare tire and other nonsense... not bad for
something rescued from junkyard.

One the other hand I still have what looks like EACV issues that I
mentioned before. Idle w/o load - 850pm. After turning on lights, rear
defroster etc. - 500 rpm. Shouldn't EACV take car of such things? When
I disconnect EACV connector RPM drops to around 700 rpm w/o load which
should be OK?

Kerozin wrote:
>> you may save yourself the time and effort by just getting another
>> throttle body. even if you get that thing back together, it'll be
>> highly suspect. shouldn't really disassemble a solenoid, just replace.n
>> only reason to try repair is if parts are otherwise absolutely
>> unavailable.
>
> Well to be honest I quite enjoyed it despite hours of time wasted.
>
> And guess what - IT WORKS! This is finished product:
> http://kerozin.dyndns.org/DSC00878.jpg
>
> I glued the thing back together, threw in 1N4005 diode for coil surge
> protection (since I couldn't find old one in solenoid) and tandem is
> now working.

excellent!!! impressive too - that solenoid was munged.

> I'll have to get new solenoid since this one will fail
> for sure after some time since it's no longer watertight and I have
> doubts how well it holds vacuum.
>
> The question is why two solenoids failed, wouldn't be surprised that
> something is blowing them. We'll see over period of few days.

i doubt they did - just that the venturi was blocked.

>
> And the car is so much faster now - manual tranny, everything stock
> minus rear seats, spare tire and other nonsense... not bad for
> something rescued from junkyard.
>
> One the other hand I still have what looks like EACV issues that I
> mentioned before. Idle w/o load - 850pm. After turning on lights, rear
> defroster etc. - 500 rpm. Shouldn't EACV take car of such things?

yes it should. what are the rpm's when starting from cold?

> When
> I disconnect EACV connector RPM drops to around 700 rpm w/o load which
> should be OK?

does it click when you disconnect it? you should hear it clicking as
you take the plug in and out. and revs should change. if no clicking,
the eacv or the electrical connection is shot. if it clicks, take it
off and see if the filter screen is clogged. i removed the screen
completely on my 90 since 89 and earlier civic's don't have one at all -
i figure the 90 can run without.

> yes it should. what are the rpm's when starting from cold?

Just a tad over 1500 rpm.

> does it click when you disconnect it? you should hear it clicking as
> you take the plug in and out. and revs should change. if no clicking,

I just noticed that idle is not always the same. On every stop I get
different idle rpm's which are stable but can be anywhere between 550
and 850 rpm.

> the eacv or the electrical connection is shot. if it clicks, take it
> off and see if the filter screen is clogged. i removed the screen
> completely on my 90 since 89 and earlier civic's don't have one at all -
> i figure the 90 can run without.

Will try that in a few days and I'll send injectors from old TB for
rebuilt since I can get that done for free.

Kerozin wrote:
>> yes it should. what are the rpm's when starting from cold?
>
> Just a tad over 1500 rpm.
>
>> does it click when you disconnect it? you should hear it clicking as
>> you take the plug in and out. and revs should change. if no clicking,
>
> I just noticed that idle is not always the same. On every stop I get
> different idle rpm's which are stable but can be anywhere between 550
> and 850 rpm.

sounds like insufficient air flow on the eacv valve - you're idling
without supplemental control.

>
>> the eacv or the electrical connection is shot. if it clicks, take it
>> off and see if the filter screen is clogged. i removed the screen
>> completely on my 90 since 89 and earlier civic's don't have one at all -
>> i figure the 90 can run without.
>
> Will try that in a few days and I'll send injectors from old TB for
> rebuilt since I can get that done for free.
>
bet you never need to use them!

> sounds like insufficient air flow on the eacv valve - you're idling
> without supplemental control.

Damn, drove a car to work today and throttle response delay is still
present and I can fell slight hesitation around 3krpm but that was
there before TB swap.

I can't think of anything on TB that may cause such behavior. There's
fuel pressure regulator on it and nothing else.

I did change spark plugs and fuel filter at the same time as TB but
engine is working smoothly so I don't think that has anything to do
with it.

Kerozin wrote:
>> sounds like insufficient air flow on the eacv valve - you're idling
>> without supplemental control.
>
> Damn, drove a car to work today and throttle response delay is still
> present and I can fell slight hesitation around 3krpm but that was
> there before TB swap.

check/replace plug leads and distributor cap/rotor. also, be sure the
timing belt is tensioned correctly. if it's slack, there's a lot of
flutter in the timing signals to the ecu and it starts "getting
conservative" with ignition timing. [do /not/ overtension the timing
belt either! google this group for instructions or follow the honda
service manual instructions to the letter.]

>
> I can't think of anything on TB that may cause such behavior. There's
> fuel pressure regulator on it and nothing else.
>
> I did change spark plugs and fuel filter at the same time as TB but
> engine is working smoothly so I don't think that has anything to do
> with it.
>

> check/replace plug leads and distributor cap/rotor. also, be sure the
> timing belt is tensioned correctly. if it's slack, there's a lot of
> flutter in the timing signals to the ecu and it starts "getting
> conservative" with ignition timing. [do /not/ overtension the timing
> belt either! google this group for instructions or follow the honda
> service manual instructions to the letter.]

I still think that reason for throttle response delay and those
strange instant starts from time to time lies in the "new" TB since
those symptoms where simply not there with old one.

So I replaced today fuel pressure regulator - nothing has changed.
Tried revving w/o lambda sensor, delay still present.

Since this is really starting to **** me off, I'll recheck throttle
angle sensor, replace injectors with old ones and well, after that
there's nothing left to repair on TB.

Will post results tomorrow.