HELP! failed emission inspection with high HC ppm

Hi everyone,

I am living in ontario and need to do emission testing every 2
years.My car is 1994 Hyundai Elentra 1.8L, and it is running fine
except emission testing

Until now I have already failed two times, both of them are one
reason, that is high HC ppm
first time I got report as
40 km/h CURB IDLE
limit reading limit reading
HC ppm 68 78 150 14
RPM 2080 valid
the rest of data are all fine
my mechanic suspect there is problem with RPM, so he changed the
spark advanced(forgive me my spelling) and decrease the RPM

The second report got even worse as
40 km/h CURB IDLE
limit reading limit reading
HC ppm 68 90 150 16
RPM 1845 valid
i suspect there is small problem regarding it, but i dont have any
idea same as my mechanic guy. He told me he is just thinking about why
we changed parts but got even worse result.

Anybody have same problem before, and how you deal with it please
give me a hands because i really need this car to go to work

Thank,
Robert

well I used to have a california smog license. You don't have a
problem with CO (carbon monoxide) or Nox (nitrogen oxide), right? If
you don't then you have to see what a high HC reading is. HC is raw
gasoline. If you have a misfire at high rpm then perhaps wires and
plug change could help. Do you notice the engine shaking or running
rougher at higher rpm, then it could be a bad plug or wire or coil.
Since your HC reading is acceptable at idle I don't think you have an
air leak into your manifold. Check your charcoal canister to make sure
it is not saturated with gas. Also check vacuum lines which are
activated off idle for cracks or leaks or BBs in them (some one may
have plugged them. Lastly it could be a bad catalytic converter, but
that is expensive.Also have someone with an oscilloscope check your
oxygen sensor. Also make sure vacuum lines are routed correctly.
You say car runs fine so we are ruling out jumped timing belt or
something like that. Alot of earlier excels had that big cat in
exhaust manifold that would plug, but I haven't worked on later
Hyundais.

On 28 Mar 2005 19:29:53 -0800, (Robert) wrote:

>Hi everyone,
>
> I am living in ontario and need to do emission testing every 2
>years.My car is 1994 Hyundai Elentra 1.8L, and it is running fine
>except emission testing
>
> Until now I have already failed two times, both of them are one
>reason, that is high HC ppm
> first time I got report as
> 40 km/h CURB IDLE
> limit reading limit reading
> HC ppm 68 78 150 14
> RPM 2080 valid
> the rest of data are all fine
> my mechanic suspect there is problem with RPM, so he changed the
>spark advanced(forgive me my spelling) and decrease the RPM
>
> The second report got even worse as
> 40 km/h CURB IDLE
> limit reading limit reading
> HC ppm 68 90 150 16
> RPM 1845 valid
> i suspect there is small problem regarding it, but i dont have any
>idea same as my mechanic guy. He told me he is just thinking about why
>we changed parts but got even worse result.
>
> Anybody have same problem before, and how you deal with it please
>give me a hands because i really need this car to go to work
>
>Thank,
>Robert


IMHO,

I would just go through the normal tune up proceedure. To stop
sending hc to the cat. Then I would find out why the cat is letting
hc's out.

hth,

tom @ www.ChopURL.com

It could be caused by one of several things, but improper timing and
RPM would not be on the list. I'm concerned because your mechanic
seems to be blindly changing settings and swapping parts rather than
analyzing the problem. I would take the car to a dealer, or somemone
who can hook the car up to the computer, read any fault codes and then
follow the steps necessary to narrow down the cause of the high HC
reading.

I agree with the real tom's post above. Had the exact same problem (high
hydrocarbons) with my 90 Lumina. Changed the cat converter and it has passed
two emmission tests so far with flying colors. Just my 2 cents

Dana S.
Waterloo, ON


"John S." > wrote in message
oups.com...
> It could be caused by one of several things, but improper timing and
> RPM would not be on the list. I'm concerned because your mechanic
> seems to be blindly changing settings and swapping parts rather than
> analyzing the problem. I would take the car to a dealer, or somemone
> who can hook the car up to the computer, read any fault codes and then
> follow the steps necessary to narrow down the cause of the high HC
> reading.
>

If taking it to an emission tech isn't an option or desired, using the
"shotgun" approach is pretty common. By "shotgun" I mean trying many
cheap attempts and taking a chance that it will get you through the
AirCare test. I've used synthetic engine lube, fuel additive, superior
air filter and these have worked but eventually it will catch-up with
issues that need fixing. The last time I had all my bases covered and
the gas cap was the culprit. From then I kept the original in the
glove box and switched it when I got home.