A few days ago I took my 91 in for a smog check & it failed due to high hydrocarbon at low rpms. Last night did a full tune up on it & it runs better so I'm hoping that gets me a passed test. It measured 150 @ 15mph & the max allowed is 114. Anybody with any knowledge on this think the tune up will reduce that number? This is the 1st car I owned that failed the emissions test.
Hydrocarbon~California emissions
- Thread starter smccprez
- Start date
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yes, a tuneup will reduce the number.
what I would do is pull the spout connector. it will lock timing at 10* and general experience is that alone will cut emissions roughly in half. only a very careful inspection by the smog tester will reveal the missing jumper.
what I would do is pull the spout connector. it will lock timing at 10* and general experience is that alone will cut emissions roughly in half. only a very careful inspection by the smog tester will reveal the missing jumper.
sperold
Last to Know
Here you go.....
http://www.shoforum.com/showthread.php?t=56278
http://www.shoforum.com/showthread.php?t=56278
sdpatt
Sr. SHO Engr.
The SPOUT (spark output) plug removal will aid in NOx output reduction, but I don't recall it helping the HC numbers. The unburned HC number is a sign of incomplete combustion and is benefited by a tune up as found by the OP.
The non-California 3.0L engine did not come with EGR, which was added to lower the combustion temperatures and NOx production. The 3.0L was not designed for the modern emissions test criteria.
The SPOUT is wired in the same harness as the ECC code reading connector and is the gray, square headed plug located above the CID sensor. I would use medical forceps to pull it. I won't need to touch it next year as the Texas law says 25-year old cars need inspection for safety aspects only. My 25-year old girl was born in January 1991.
The non-California 3.0L engine did not come with EGR, which was added to lower the combustion temperatures and NOx production. The 3.0L was not designed for the modern emissions test criteria.
The SPOUT is wired in the same harness as the ECC code reading connector and is the gray, square headed plug located above the CID sensor. I would use medical forceps to pull it. I won't need to touch it next year as the Texas law says 25-year old cars need inspection for safety aspects only. My 25-year old girl was born in January 1991.
