Emission HELP- fail HC at idle!

[MrSamson]

Hello.

I am hoping to get some ideas on what i might be able to do to help pass emissions.

I live in Vancouver, WA.

I have a 1988 5speed accord LX carberated.....200K miles on engine

Today I tried to pass emissions and failed the HC limit at idle. I DID pass the cruise limit.

ALSO- this car passed 2 years ago previously.

Earlier today the car was NOT starting. I replaced the rotor and rotor cap on the distributor and the car started up!

My next guess is to maybe try changing the spark plugs as well as a first, next attempt.

Anyway, here are my readings:

IDLE numbers:

HC = 1372, pass is 220
CO% = 0.16 (limit is 1.2 so this did pass)
CO + CO2 (%) = 7.96
O2% = 9.77
RPM = 1070

Cruise numbers:

HC = 106
CO% = 0.09
CO + CO2 (%) = 12.29
O2% = 3.86

Like I stated previously my first, cheap guess attempt would be to change the spark plugs. I pulled one spark plug previously and it was covered with DARK, BLACK soot.

This is frustrating because I think this is, ironically, the last emission test it will have to pass given that emissions at this time is not required for vehicles older then 25 years.

Is there any dope I can put in the gas to help get this baby to pass!

When I move some day, one of the requirements for new residence will be NO more emissions testing.

Hopefully I can get some ideas here on what I might want to attack. It seems like there is something funny going on here...perhaps a sensor or something?

Thanks in advance for any responses that might be provided on here and have a good day!

MrSamson

[Dr_Snooz]

I suspect you will be having carb trouble in the near future. For the test though, the idle mixture adjustment screw controls the mixture at idle. Someone else will have to tell you where that is on the carb. If it were my car, I'd just turn down the idle mixture screw. Once you pass, turn it back. That is the easiest way to get yourself past the test, but won't fix what's going wrong with the carb.

[MrSamson]

Good advice and I am going to play with that tomorrow I little more.

If I can get past this stupid emissions test...i have a 2 year window to have fun with car.

The new carb is sitting on the counter in the garage - Weber 32/36.

If I fail - there is a waiver form that requires money towards remediation through a qualified shop as well as an under-hood inspection at that point, and the Weber would get me revoked at that point.

I am just hoping to and trying to jump through this paperwork/emissions hoop.

Good times.

[ecogabriel]

I may be talking nonsense, but is there an O2 sensor in the carbed cars? I have seen O2 sensors listed for carbed cars in Rockauto.com, and I also remember reading that the carbed cars have some kind of "ecu" for the carb.

Anyway, look down the exhaust manifold to the side pointing to the engine mount (the one at the front of the car).... it should be there. If there is a O2 sensor, replace it

Finally, don't they test for NOx? If it is running rich the NOx should read low - the extra fuel cools down the combustion chamber.

[nswst8]

Old school trick, is to run one gallon of laquer thinner with a half full tank of gas for 150 miles. Or you can sea foam it. This will help to remove excess HCs. A basic tune up is in order as well.

Then when you retest, you must get the catalytic converter up to operating temperature. This is either driving it for 40-60 miles before the test and let it idle while your waiting for the test.

[MrSamson]

I am going to install the weber since I found a work around for one year.

Should be interesting and I will probably start another thread for it.

Thanks for the ideas tho!

[Oldblueaccord]

That HC was at 1050 rpm that might be a little high. You might be getting into the main circuit a little at that RPM. Lower the RPM to the correct idle speed to stay on the idle circuit.


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