

| Subject: | Re: Failed emissions testing |
| From: | Todd.Last |
| Date: | Sun, 9 Jan 2011 12:02:04 -0800 |
It is both an idle and 2500rpm test. Thanks for the tips! Todd On 12/30/2010 9:04 PM, Dennis Haynes wrote: > Over the years I have responded to emissions issues many times. There should > be some good info in the Archives. > > I am assuming this is only an idle test. It makes a huge difference if this > is a 2,500 rpm test. > The 1.43 CO tells me the O2 sensor or circuit is not working or so many > other things have been tampered with/miss adjusted that it cannot > compensate. > > The O2 sensor circuit should regulate the mixture around .5 CO even before > the Cat. This alone will also bring down the HC. If the CO was within normal > limits then excessive HC could be the result of an ignition miss, incorrect > timing, idle speed, or a valve/engine problem. If the injectors are slightly > out of tolerance or the engine has some issue a correct overall mixture can > result in one or more cylinders running lean causing what is known as a lean > miss fire. This lean miss will result in excessive CO. > > Test the O2 sensor, a digital voltmeter will do wonders here. > Check timing and idle speed settings. Avoid temptation to advance the timing > to make the engine smoother or more responsive. The advanced timing will > reduce the amount of air/fuel needed for the given idle speed increasing > both the CO and HC. Cheat just a little on idle speed, 950-1,000 rpm no > load. > > To test the cat have the CO measured before and after. With a properly > working cat and all other engine issues CO and HC should be near "0". > > Dennis > > -----Original Message----- > From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of > Todd.Last > Sent: Thursday, December 30, 2010 10:49 PM > To: vanagon@GERRY.VANAGON.COM > Subject: Failed emissions testing > > I went to have my Westy emission tested today, and it failed the test. > The van had been sitting for a number of months, and when I first > started it, It sounded like one lifter was devoid of oil. I let it run > for awhile and the noise went away. > I'm not sure, but it looked like the oil was a bit overfilled as well. > Anyway my numbers were (at idle) > > 270 HC (Max allowed is 220) > 1.43 CO (Max allowed 1) > > Any suggestions on what to adjust to try again? > > thanks, > Todd > '88 Westy > >
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