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FAILED emisions (California) on 1988 COLT

It's fine (way below average) at 2500 RPM, but fails at idle. Compression is fine. Jet valves are fine.

Did change oil, spark plugs, wires, cap and rotor.

Still fails at idle (HC a little too high) reads 170 ppm, max allowed is 120, average is 20.

At 2500 RPM, it is near average!

I'm thinking raising the idle speed by about 50 RPM, and either partially shunting the CTS, or putting a resistor in series with the MAF sensor.

I just added a bottle of CRC "Guaranteed to Pass", will run the tank almost empty, refuel, and re inspect. But I am skeptical of any "snake oil". It's probably just Stoddard Solvent, and maybe a little Techron. But what the hell...

There might be an ECM hack, too. Anybody?

Any other ideas? I just want to get the damned thing to pass! I really need to make this vehicle pass!

Reply to
~^Johnny^~
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You might have one of 3 problems.

1.A dirty air cleaner will do this.
  1. A dirty throttle body will do this. Get some throttle body cleaner, hold or jam the throttle butterfly open all the way, spray all inside liberally, and wipe it out with a cotton rag, and do it all a second time or more till the rag comes out clean. You will notice the engine will run smoother at idle. This is caused by the breather tube which is piped into the throttle body depositing oil vapor which accumulates behind the butterfly and messes up the idle airflow.
  2. Your EGR valve might be worn out at the valve tip face, maybe needs a new one or at least a good cleaning. The carbon particles that accumulate here over the years are abrasive and then wear out the valve tip or the seat, and it leaks too much at idle. 4. It is always a good idea to run fuel injector cleaner in your gasoline every third tank of gas, because the oil companies put varnish in the fuel to plug up your fuel injectors so you will get worse mileage. It is in their best interest to make you buy more of their product, kind of like the ciggarette manufacturers adding stuff to get you addicted to their product so you will buy more. A clogged injector makes large droplets of gas which do not burn as completely and you get more emissions and worse mileage.

Good Luck.

Reply to
fastcarface

Interesting, but methinks bullshit...

Phillip Morris comes to mind. There was a big lawsuit a while back. They were accused of "adding extra nicotine" to their tobacco. Well, it was debunked.

So, I find this a little far-fetched. Crazy, in fact. For instance, Chevron adds "Techron" to their fuel, to keep your injectors clean. Is that to make up for the varnish they allegedly add to their gasoline? :-)

Your mileage may vary.

Gasoline or Vaseline? ;->

Reply to
~^Johnny^~

The TB was clean, as was the MAF wire. Plugs looked good, with no foulng and slight normal wear, but I changed them out anyway with NGK (Autolites were in there before).

I did an oil change, using Valvoline 10W30, with a new Penzoil filter, dumped a bottle of "Guaranteed To Pass" into the tank, then took the car out on the open road for a good old fashioned "Italian Tune-up". I gave it hell. Burned pert near the whole tank near rev limit.

Two tankfuls of petrol later, took it in for re-inspection, and it passed with flying colors.

Thanks to all who offered advise.

Reply to
~^Johnny^~

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