E Test ownage!

[VTEC_Inside]

I'm tickled pink over this so I have to share.

My '89 has been on a conditional e test pass since Jan 2004. Left with the impression that the cat was the culprit, I changed it prior to this years first run.



From first to second test I:
-replaced the 02 sensor which brought the CO down to .46% on the ASM test in 3rd gear
-replaced the distributor seal to stop it from leaking.
-tightened up the boosters (only ever so slightly budged under pressure)
-RECONNECTED the Coolant temp sensor which had come off.

Final test was done in 2nd gear. I had them run it on the analyzer prior to the actual test. CO barely squeaked above .04 during acceleration and then dissapeared.

[Run Away]

Congrats.

Glad we don't have that here, or elese I'd have to find a shady shop and pass them $200 each year at inspection.:P

[VTEC_Inside]

Congrats.

Glad we don't have that here, or elese I'd have to find a shady shop and pass them $200 each year at inspection.:P

Thanks, heheh...

If mine was fuel injected, the CEL would have tipped me off to the disconnected coolant temp sensor. I don't think you'd have any trouble with your Prelude.

[Run Away]

Carbs are a bitch plain and simple.
Especially the setups on late 80s economy cars, there are millions of vacuum lines that  go everywhere. An old carb'd V8 wouldn't be as bad.

My car would not pass due to no cat, plus it burns a quart of oil per tank.

[VTEC_Inside]

Carbs are a bitch plain and simple.
Especially the setups on late 80s economy cars, there are millions of vacuum lines that  go everywhere. An old carb'd V8 wouldn't be as bad.

My car would not pass due to no cat, plus it burns a quart of oil per tank.

Vacuum lines you say? You mean THESE!!!


Which go into here:


Lol...

I have printed pages from the service manual for my car. There are exactly 20 different items under the hood that are part of the "feedback control system". The fuel injected version in comparison has like 8 items. Makes me seriously wonder why they continued the carb model after 87 when they introduced the majority of the shit under my hood.

In your case, yeah, I'd imagine that you'd need a cat :), but I wouldn't be too concerned with the oil consumption. Mine uses a bit of oil as well. After seeing these results I'm inclined to think that the majority of it is just leaks. I replaced my distributor seal last week. I'm going to retorque the valve cover to see if I can stop/slow the hemmorage I have from there at the moment.

[Tom]

Good job

When I read "E Test" I though you were referring to getting the gas gauge needle as far to the left as possible  I've been pretty broke lately and putting in a few bucks worth of gas at a time, so I've had some close calls.  Of course, some people (Kramer) do it for fun :D  

[mazda6er]

Good job

When I read "E Test" I though you were referring to getting the gas gauge needle as far to the left as possible  I've been pretty broke lately and putting in a few bucks worth of gas at a time, so I've had some close calls.  Of course, some people (Kramer) do it for fun :D

It's actually a sport in Europe.    

[Run Away]

Kinky europeans. ^_^

[VTEC_Inside]

Good job

When I read "E Test" I though you were referring to getting the gas gauge needle as far to the left as possible  I've been pretty broke lately and putting in a few bucks worth of gas at a time, so I've had some close calls.  Of course, some people (Kramer) do it for fun :D

It's actually a sport in Europe.  

lol....  

[280Z Turbo]

Carbs are a bitch plain and simple.
Especially the setups on late 80s economy cars, there are millions of vacuum lines that  go everywhere. An old carb'd V8 wouldn't be as bad.

My car would not pass due to no cat, plus it burns a quart of oil per tank.

Did you ever try some of that engine restore stuff that comes in a can? It may help alleviate some of that oil consumption for a while. Although, I don't know how it would pan out for you in the long term. :ph34r:

The coolant temp sensor is an important part of an old Bosch EFI system! (Is that a Bosch system?) It must have run quite rich without it.

[VTEC_Inside]

The coolant temp sensor is an important part of an old Bosch EFI system! (Is that a Bosch system?) It must have run quite rich without it.

If that was directed at me, the answer is no. It is Carbureted. Its a Keihin 2bbl.

[280Z Turbo]

The coolant temp sensor is an important part of an old Bosch EFI system! (Is that a Bosch system?) It must have run quite rich without it.

If that was directed at me, the answer is no. It is Carbureted. Its a Keihin 2bbl.

Oh that's right! I didn't read it closely at first.

What the heck does it do with the data obtained from the 02 sensor and coolant temp sensor? :blink:

[Run Away]

Carbs are a bitch plain and simple.
Especially the setups on late 80s economy cars, there are millions of vacuum lines that  go everywhere. An old carb'd V8 wouldn't be as bad.

My car would not pass due to no cat, plus it burns a quart of oil per tank.

Did you ever try some of that engine restore stuff that comes in a can? It may help alleviate some of that oil consumption for a while. Although, I don't know how it would pan out for you in the long term. :ph34r:

The coolant temp sensor is an important part of an old Bosch EFI system! (Is that a Bosch system?) It must have run quite rich without it.

Sean: Yes I tried a can of restore. Pretty sure it did Jack Chit.

I'm done with snake-oil additives, it's smarter, cheaper, and easier to buy quality oil in the first place.


I don't know what a carb'd engine would do with an 02 sensor, but the coolant temp sensor would probably work with the choke for cold starts.
Disconnected temp sensor= runs rich because it thinks the engine is stone cold I would guess.

[VTEC_Inside]

The coolant temp sensor is an important part of an old Bosch EFI system! (Is that a Bosch system?) It must have run quite rich without it.

If that was directed at me, the answer is no. It is Carbureted. Its a Keihin 2bbl.

Oh that's right! I didn't read it closely at first.

What the heck does it do with the data obtained from the 02 sensor and coolant temp sensor? :blink:

The above diagrams show the majority of the "basic" vacuum system on an '86-'87 model.  Its missing 2 critical items that are part of the "feedback system" that was added in '88.

The carb on my car is set up to run rich plain and simple on my car. There are two "Air Contol Valves" on the intake manifold that introduce the air required to reach the magical 14.7:1 mix.

As much as I've learned I still don't understand exactly how it meters in the additional air.  It is those valves that are ultimately controlled by the "data" received by the 3 major sensors (Intake temp, coolant temp, O2)

Suffice it to say that its an absolute nightmare to troubleshoot which has made my success incredibly rewarding. I've been passing out copies of my etest results to everyone I know, lol....

Here is a diagram listing all the emissions controls components featured on the '88-'89 carb models. The EFI version of the car has like 8 items instead of the 20 here, which really makes me wonder why they continued to make the carb model. Between all the vacuum lines and individual components I find it hard to believe that the EFI system could have cost that much more to produce.

[VTEC_Inside]

I don't know what a carb'd engine would do with an 02 sensor, but the coolant temp sensor would probably work with the choke for cold starts.
Disconnected temp sensor= runs rich because it thinks the engine is stone cold I would guess.

The choke is actually a 100% independent entity from the emissions system on my car.

Its partially controlled by thermovalve A and primarily by an independent heated bimetallic "spring". Ignoring all vacuum the choke will completely open after about 2-5min (depending on outside temp) as the spring uncoils, assuming of course that there is power to the spring. :)

At idle the feedback system is ignored. There is an idle air/fuel mixture screw on the back of the carb. (It is capped off and can only be accessed by removing the carb and then the cap.) You'll note that idle emissions were never really an issue, most likely improved when I cleaned up the distributor and replaced the seal.

Correct about the assumption that no temp sensor = car thinking its -40c though.

I didn't mention it above, but all said and done, I had the car on the exhaust analyzer 3 times. The first after the o2 sensor replacement.

The 2nd after I replaced the IAT sensor with one from an '87. This was a mistake in that the '87 sensor was just a switch that went open at 21c.  With that sensor on it the car thought that the intake air was also -40c and the CO emissions went over 3-4% when run in 2nd. Needless to say, I did some more reading and then discovered how different the later years systems were and put the original sensor back on after checking it.

The 3rd was just prior to the final "official" test. What a difference though. When run on the analyzer you get to see a real time measurement of the gasses. On that final run CO never went over .03% and that was only on the acceleration up to 40kph.