Hi Eric, Yes, the O2 sensor is brand new. The smog station I go to runs the car at high rpm to get the cat nice and hot immediately before starting the test. The cat appears to be working - HC and NOx levels are low. But the O2 is at 0%, so there's none left to convert the CO to CO2. That's why is suspect the mixture is rich. Maybe the injectors are getting old and leaky so the ECU can't control the mixture tight enough. I'm going to try tightening the air flow spring (per your instructions) to see if I can lean things out a bit. I'll let you know how it turns out.
Cheers, Charlie On Wed, Feb 9, 2011 at 7:30 AM, Eric J Russell <[email protected]> wrote: > Do you know how old the O2 sensor is? Anything more than 60,000 miles is > suspect. 90,000 miles is past its prime. Even if it is 'working', when they > get old they slow down (response time) and the computer may decide to > ignore > a slow response - defaulting to its slightly richer map. > > Was the catalytic converter fully warmed up? Even if the car had been > driven > for a while before the test if it had been parked for a little while before > the test the catalytic converter could have cooled down. Maybe. > > Eric Russell > Mebane, NC > http://home.mebtel.net/~ejrussell > ----- Original Message ----- From: "alfa-digest" < > [email protected]> > > Date: Mon, 7 Feb 2011 00:21:15 -0800 >> From: Charles Slayman <[email protected]> >> Subject: [alfa] Marginally High CO Emission from L-Jet Spider >> >> Dear Alfisti, >> >> I just failed the bi-annual California emissions test on my '89 L-Jet >> Spider for marginally high CO at 25mph. Here are the results: >> >> 2801 @15mph, Max CO Allowed 0.78%, Measured CO 0.78% PASS >> 2870 @25mph, Max CO Allowed 0.66%, Measured CO 0.78% FAIL >> >> The other tests (HC, NOx) passed and actually get better with speed, so >> the >> catalytic convertor is working. This looks like a problem with the >> mixture >> running rich. The O2 sensor is working and the temperature sensors are >> working (so the L-Jet is not running rich intentionally because it thinks >> the engine is cold or the O2 sensor is dead and defaulting to a rich >> condition). >> >> Have any of you experienced a rich condition on an L-Jet that was not due >> to >> a dead O2 or temperature sensor? >> >> Thanks, >> Charlie -- to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi or email "unsubscribe alfa" to [email protected]
