My 420 SEL Failed VA Emissions - Help Please
 

My 1986 420SEL with 224,762 miles has failed VA emissions. Here are the test results:

15MPH Test
Test Limit Reading Result
HC ppm 65 149 Fail
CO% 0.26 0.23 Pass
NO ppm 857 375 Pass
RPM 1304 Valid
Dilution 14.6 Valid

25MPH Test
Test Limit Reading Result
HC ppm 119 229 Fail
CO% 0.38 0.35 Pass
NO ppm 833 623 Pass
RPM 1240 Valid
Dilution 14.6 Valid

Visble Smoke Inspection Pass


My question is: What would cause high HC readings and what are some things I should be checking for?
Thank you

Ah the power of the SEARCH facility:

http://www.peachparts.com/shopforum/search.php?searchid=456711

What are the search arguments?

If you haven't changed out your O2 sensor in a while, I would start there. When fully warm, the exhaust should smell of nothing but hot air. If it doesn't you probably need a tuneup and/or mixture adjustment.

Also heard that a new air filter and oil change can get a borderline car thru. Make sure the engine is full warmed up when you go.

Oh, I don't know - use your imagination like "emissions" and "emission".

You might even ascertain that a certain individual has written many long, detailed posts on emissions including how emission control systems work, how to analyze test results to determine possible malfunctions, how to properly "condition" your car for emission tests, etc.

Once you determine who that person is, use the above arguments and his screen name to search.

Duke

Go to SEARCH.

In this case, I keyed in "failed+emissions"

The double quotes were not included. I then clicked on "titles only"

If you click in the URL I posted above, you get nothing. I cannot tell you why this now happens. At one time you could scan for all threads that contained a specific data string like the one I just used and if there were any, they would appear. You could then cut-n-paste that URL and post it as I did.

Now at this site, after a short period of time, you get something like "sorry...nothing found" if you click on what I provided above.

I have long been amazed by the numbers of people who frequent this site who appear to have no clue how to use a SEARCH facility.

It's no wonder all the jobs are going overseas.

In closing, I would also look at Duke2.6's signature. Graduate degree in Mech. Engineering with service in an engine facility at a major university. Duke has provided a great deal of insight into engine performance, emissions, etc.
I read everything he writes. Scan for the posts he's participated in.

Pass that Emissions Test!
 

At the auto stores down here, they carry a gas tank additive from CDC called "Pass the Emission Test".

running too rich
 

Runs some TECHRON through it to cleam off the intake valves real good, change the oil, change the air filter, change the spark plugs, Make a 20 mile run at >100MPH to clean off the cats, drive HOT to th inspectionstation. If that doesn't work, adjust the fuel mixture a tad leaner. Next actio is to replace the catalysts (these are oxidation only--not 3 way I think)

OK, OK, OK, you made your point. :)