Date: Wed, 26 Feb 2003 09:10:15 -0600 From: "Walt Kienzle" <wkienzlenospam.net> Subject: Re: emissions problems Re: Help
I don't think that heating the sniffer wand with a space heater would cause a problem, although the heat from your exhaust should have been sufficient to keep everything warm. The emissions test in my area (Chicago) don't seem to have a special calibration cycle that I have noticed, and I have never seen anybody heat the sensors. I have had my cars tested in winter, and it gets below freezing here too. The HC levels seem OK, maybe a little higher than normal. I had to go to an old report where they measured HC in PPM (220ppm is the limit for us), but now all the results are reported in grams. My cars typically put out 5 to 7 PPM. I have one report that showed 63 PPM, so your result might indicate that the car hadn't warmed up fully yet -- another indicator of a potential thermostat problem. I doubt if the low fan switch is causing the problem, unless you hear that the fan is running with the temperature indicator in the low position. Things to try: - Replace the thermostat (air filter and spark plugs too) if that hasn't been done recently (recently being 20K miles for plugs, 40K for the filter, and 60K for the thermostat). They are all relatively low cost and moderately easy to replace. - Get a tankful of gasoline with 10% ethanol (if that isn't what you usually get). If it isn't available in your area, get a tankful of regular gas (even if that isn't what you normally use) and add in two or three bottles of gas line anti-freeze. Try to find ones that have ethanol as the main ingredient instead of methanol, although either will work for this purpose. - Make sure the engine is fully warmed up before testing. Take it for a 15 minute drive on the expressway before testing if that is possible. Good luck. Walt Kienzle "R Ellefson" <ellefson3nospami.com> wrote in message news:3E5C1364.9DF39B37nospami.com... > high speed 1921 rpm 25 > mph low speed 1682 rpm 15 mph > HC(ppm) 77ppm hign speed (168 std) pass > 155 low speed (173 std) pass > CO% 0.60 (std 1.08) > pass .40 ( std 0.98) pass > CO2% > 14.6 > 14.8 > O2% > 0.4 > 0.5 > NOx(ppm) 1269 (1208 std) > fail 2368 (1323 std) fail > Dilution 15.1 (>6.0 std) > pass 15 (> 6.0 std) pass > > Does this help any ? I'm still confussed what can I do to correct this > problem. I should also add that the > ambieant air temp was between 20 - 30 F and the operator had to put the > sniffer wand end into a electric space heater grill to get the machine to > calibrate. The machine wouldnot calibrate until he did this he tried 3 times > before doing this to get the machine to calibrate. Would the difference in the > actual air temp and the calibrated temp give different # based on air density. > ie colder higher emissions readings? Also colder engine higher readings? > > Walt Kienzle wrote: > > > Maybe my memory fails me, but I thought that high NOX readings were either > > from a lean fuel mixture (too much nitrogen rich air) and/or excessively > > high combustion temperatures. The EGR valve is designed to route some > > exhaust gas back to the intake to reduce the combustion temperatures and NOX > > emissions. > > > > Most likely the thermostat is stuck open or partially open and this will > > cause poor gas mileage, but the emissions issue might be a different > > problem. Does your emissions test also measure HC (Hydrocarbons)? That > > would be the high reading if the fuel mixture was too rich. > > > > Walt Kienzle > > 1991 9000T > > > > "R Ellefson" <ellefson3nospami.com> wrote in message > > news:3E5B92C3.8CB36D10nospami.com... > > > I have a 88 16v non turbo, it failed the NOX emissions test. I have > > > noticed the it is using excessive gas in colder weather, I also noticed > > > that when the emissions test was being run it smelled almost as if the > > > car was running rich. I notice that the temp gage never gets to the > > > middle but stayes in the lower third of the gage. Could my problem be > > > excessive richness causeing both the emission problem as well as the gas > > > consumption increase in cold weather, and could this richness be caused > > > by a thermostat and or fan temp switch which are to low for cold > > > weather? > > > > > > Thanks > > > Ron > > > >
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