At the helm by dave helms


The Colorado Emissions Test.


The sheer mention of this can raise the hair on any Ferrari owner’s neck. But, there are ways that you can prepare yourself for this, and make the experience a little less terrifying. 

In a word, MAINTIANCE.  In The past 5 years, there has only been 2 Ferraris that I have not been able to get through the test blowing adequately low numbers to get the cherished window sticker.  Now don’t get me wrong, these were not all “show room perfect” cars!  Most have had various emission related components mysteriously misplaced over the years, but in good running condition will still blow good numbers.  The key words here are “good running condition”.  Properly maintained, the Ferrari engine is very efficient power plant.  Even at that only 20% of the fuel taken in is used to make power, with 80% going towards cooling and and losses.

Bringing back ones Ferrari to a point where it runs clean enough to pass the emissions test can be a humbling experience, but the residual benefits of a properly set up engine are why you purchased the car in the first place- PERFORMANCE! 

Lets first describe what you are looking at when you inspect the sheet handed to you with the highlighted “FAILED” responces.  There are two basic things that we are looking at, CO and HC.  If we get those in the range all the others will follow in line.  To simplify things, CO is the measure of how much fuel is going into the engine, and HC is the measure of how efficiently the engine is burning it.  When the CO numbers are too high, the fuel system is metering in too much fuel.  When the HC numbers are too high, this shows there is a large amount of “unburned hydrocarbons”, or unused fuel still in the exhaust.

This is were the maintenance issue comes in.  There is a specific order in which things must be done to get everything working correctly.  First, the engine must be in good mechanical condition.  The compression in all of the cylinders must be fairly near spec and evenly balanced.  The components that are used in most of the engines are incredibly reliable.  It has been over 10 years since I have had to do a valve job because of a burnt valve on a V-8 Ferrari engine.  There have been some problems with the 95’ 355 engines relating to valve guides (Oops!), but Oh what a feeling when they are done and things work right!  Second in line is the ignition system.  If you don’t get a good spark at the proper time, even the best of engines with a perfect air / fuel ratio won’t run correctly.  The last to do is often the first to be tinkered with, the fuel system.  In a perfect world the ratio of air to fuel should be approximately 14 to 1, which is what all of the sensors in the computer controlled cars are striving to obtain.

Now, with a basic understanding of what the numbers mean, on to the “What can I do, and how will it help me” question. Lets take things in the order that I spoke about before and look at the most common problems I find.

Mechanical:  Valve adjustment.  If valves are not set to their proper clearances, compression losses will result.  All cars prior to the 355 have adjustable valves that have to be adjusted every 15,000 miles.  Worth mentioning at this point is the valve guide problems with the 355.  Even though it has hydraulic cam followers that do not require adjustment, when the guides go bad, carbon build up on the valve face from the resulting oil leak mimics an out of adjustment valve, and results in a compression loss. 

Ignition:  As most of the cars that require the emissions test are no longer using points, I will stick with the most common problems on the electronic ignition cars.  Consider the working conditions the spark plug extensions endure.  At roughly 4” long and made of a molded plastic resin, the extension is expected to transfer some 30,000 odd volts from the plug wire to the spark plug.  Now if that is not bad enough, put it in a valley, cover the top with the plug wire valley boot and turn up the heat to roughly what you cook a roast at.  Hear a miss? This is a good place to start looking!  Now, how hard did you have to tug on that plug wire to get it off the spark plug?  The conductor wire that carries the 30,000 volts is only about twice as thick as a human hair, with the rest of the thickness of the plug wire being used for insulation to guide the spark to where it belongs.  Ever set your hand on a plug wire where the insulation was no longer up to its task?  Now, this will change your day!  Spark plugs are the last of the common problem areas. Deposits that build up on the plug can have a great effect on how well it will shoot that perfectly timed spark across the gap.

Fuel system:  Assuming everything else is in good order, this should be your last hurdle.  First a word about gasoline.  Fresh is good!  When left to sit for months, a large portion of the volatile portion of the fuel will evaporate and leave you with a marginally flammable mixture.  The gas available at the pump now a days is just barely flammable as it is.  Octane is a measure of the fuels ability to prevent pre-ignition, also known as knock or ping.  A higher-octane fuel will burn slower than a low octane rated fuel.  To get that “gold ring” window sticker, faster burning fuel is better.  Once the trophy is displayed in the window, fill it up with the highest-octane fuel available at the pump!  Alcohol makes a good Scotch much more fun, but is a real pain in a carbureted car when trying to pass the test.  Alcohol boils at a much lower temperature than pure gasoline and is the reason your carbureted car starts to die at idle when caught in traffic or is a real pain to start after a short stop at the store. A blended mix of alcohol and gas will burn cleaner than pure gasoline, BUT the car must idle to pass the test!  Clean injectors/jets are a must for the Ferrari engine to perform at its peak, and to “blow good numbers”.  Both need cleaning on an occasional basis to stay in peak form.  Rejetting the carburetors should only be needed when a car is brought to this area from a much lower altitude.  Remember that 14 parts of air to 1 part of fuel?  The fuel settings have not changed when the car was brought here (assuming it is not computer corrected) but, oxygen is a good thing, and we have less of it here than at sea level, resulting in a ratio closer to 10 to 1. With this in mind imagine what the ratio will change to if you add to the mix a dirty air filter, and cut the air portion of the ratio down farther. Resetting the basic jetting on carb cars, and the base fuel injection settings is a must do when cars are brought here from much lower altitudes.  One final word on fuel is in order.  Remember that 80% of fuel that was not used to make power in the engine?  Some of it has found its way past the piston rings in the engine and is diluting the oil in the crankcase.  By way of the crankcase breather system the engine is burning these fumes as well as the fuel going in via the carbs or the injection system.  Changing the oil prior to going in for the test can have a great effect on the  “CO” numbers your car will show at the tail pipe.

For a great many people the Colorado emissions testing is a blessing in disguise. With out it many people would never realize how a finely tuned Ferrari really runs.