In a message dated 9/17/2007 8:36:03 A.M. US Mountain Standard Time, [EMAIL PROTECTED] writes:
I have a 1993 300E 2.8 with about 122,000 miles on it. It recently went for NJ emissions testing and failed. My HC tested at 150 instead of 100. I am told that the cause of this is not the normal tune up but rather that something is defective. the car had a tune up in the last 12,000 miles and I was wondering if anyone has any suggestions. Also want to mention that for the first 30 seconds or so I get a "tistt, tistt" sound from the air pump. After 20 -30 seconds it just stops making the noise. It is not a gradual fade but an instant turn off of the noise. I'm not sure if one is related to the other. Robb T. South Jersey Robb, Make sure the engine is coming up to design temperature. A bad thermostat, or bad engine temp sensor would leave the engine running rich if it thinks it is still warming up. On cold (rare) days at the smog place, I will request they remove the roll around fan as it can knock temperatures down some. I would consider changing out the O2 sensor, which if original, is probably due. If you have a previous history of the car running very rich, the catalytic converter could be shot too. Never go to an emissions test with a full tank of gas. The purge cannister could be venting raw gas into the engine. Just my .02 Jim Friesen Phoenix AZ 79 300SD, 264 K miles 98 ML 320, 151 K miles ************************************** See what's new at http://www.aol.com _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
