FAILED Emissions Test at Idle- HC PPM 243 (limit 220)

1989 300E (gasoline) failed the emissions test:
At idle HC is 243 PPM (limit 220 PPM).
At 2500 RPM the HC is 57 PPM (limit 220 PPM)
Any suggestions? Cold Start valve???
The car/engine has about 180,000 miles. It came from California, so it has the CA emissions system. I am trying to get it to pass the Pennsylvania emissions test.
Thanks!
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The original post was from me "Bob" not "News Groups"
The plug wires are cracked, so right now, I'm replacing the wires and plugs. The mechanic thinks that it will only require an adjustment to make it pass since it only fails at idle.
BTW CO is reading .05 % at idle and .10% at 2500 RPM. The limit here in PA is 1.2%. I don't know what "dilution" is, but it reads 15.3% at idle and at 2500 RPM/
I look forward to your feedback.
Thanks,
Bob

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Things that might work.
1) Make sure the car is HOT before testing. 2) Adjust the Idle ever so slightly lower. 3) Replace the air filter and tune it up (ignition wise)!
Marty
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Suggest you add fuel injector cleaner to fuel and check when the spark plugs were last changed. Replace them if more than 15K miles.
There are services that professionally clean gas fuel injectors but only after they're out of the engine - that's probably the next step if the injector cleaner doesn't clear the problem.
The cold start valve only operates for a few seconds when the engine is cold, not otherwise.
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Thanks for the help... tomorrow I'll pick-up an air filter and drop it off at the mechanic (local garage) as Martin Joseph suggested.
I'm wondering if is okay to put the injector cleaner in there now while awaiting the test... or will it cause the hydrocarbon (HC) level at the tailpipe to temporarily increase until it is flushed through the system. If you say that it will temporarily increase the HC, I'll take the car home if it fails again and run through a tank of gas with the injector cleaner in it.
Bob

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Injector cleaner is cheap so why not just do it, drive it for a couple of hundred miles and then test the car?
Another thought: is the engine running at 80 degrees C.? If not replace the thermostat for it's running too cold and THAT will affect emissions.
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