G
Guest
·Okay, here's the juice,
I live in Massachusetts and have a 1984 CJ-7 with a 304 V8 from an older model (circa 1978 or so). I have failed emissions twice now have have a rejection sticker stuck upon my windshield. /wwwthreads_images/icons/mad.gif
RELEVANT HISTORY LESSON ON MY RIDE:
This is what was done to the vehicle by the previous owner(s):
-AMC 304 V8 installed
-headers
-four bbl manifold
-junky 4bbl carburator
-rusty single exhaust (no catalytic converter) /wwwthreads_images/icons/crazy.gif with a SINGLE cherry bomb muffler. (Why they did this after all of the above ....I have no idea)
I rebuilt most of the vehicle over the winter months. Here is what I did to the engine that is related to my topic:
-new Holley 600 4bbl carburator (electric choke)
-Malory Unilite Ignition system upgrade (Unilite conversion part No 501)
I have not touched the exhaust system because I would like to upgrade to a dual exhaust system. I think that time is now. So I went down to my local garage and they preformed an state inspection sticker test. I failed because of emissions. /wwwthreads_images/icons/mad.gif
Now I am not 100% sure of this, but the cutoff year for emission testing on a vehicle here (MASS) is 1983. I miss it by one year. Does this mean that next year my vehicle will be grandfathered in? I am under the impression that I will have to pass emissions this year and after that will be "home free" when it come to emissions testing. Based on this, my goal was to get the vehicle to pass and THEN purchase a dual exhaust system (sans converters) /wwwthreads_images/icons/wink.gif
Here are the results of my emission test:
First Attempt:
Pollutant.....Reading.....Limit..........Pass/Fail
...HC GPM........7.85......3.20..........FAIL /wwwthreads_images/icons/frown.gif
...CO GPM......109.98.....80.00..........FAIL /wwwthreads_images/icons/mad.gif
..NOx GPM........1.73......7.00..........PASS /wwwthreads_images/icons/shocked.gif
..CO2 GPM......654.48
The mechanics couldn't believe that it passed on the NOx GPM because it was missing a catalytic converter. /wwwthreads_images/icons/shocked.gif They advised me that maybe the engine was running too rich and that is why I failed on the other two Pollutant categories.
So I went home, leaned out the carburator till she squeaked /wwwthreads_images/icons/wink.gif filled up with 92 Octane gasoline and added 107 Octane boost with Emission Control ($7.49 for 16 fluid oz /wwwthreads_images/icons/shocked.gif ) and drove around for a few days, then I returned with high hopes of passing, but failed again.
Here are the results:
Second Attempt:
Pollutant.....Reading.....Limit..........Pass/Fail
...HC GPM........7.85......3.20..........FAIL /wwwthreads_images/icons/crazy.gif
...CO GPM.......60.25.....80.00..........PASS /wwwthreads_images/icons/smile.gif
..NOx GPM........1.14......7.00..........PASS /wwwthreads_images/icons/smile.gif
..CO2 GPM......407.78
So I passed on the CO GPM /wwwthreads_images/icons/smile.gif, but still failed on HC GPM /wwwthreads_images/icons/frown.gif
This one exhaust shop offered to install a dual exhaust system with two catalytic converters, but this drove the price up $300.00 /wwwthreads_images/icons/shocked.gif And even after this is done, there would be no guarantee that I'd pass. That would sting and probably leave a mark! If I can, I would rather (space, cost and simplicity reasons) not have to deal with catalytic converters.
Any advice on what should I do? What exactly does a catalytic converter do? Is there any way to adjust timing or something to get it to pass on HC GPM without a catalytic converter? The only adjustments on the carburator are the mixture settings on each side. Or do I need to bite the bullet and spend the extra cabbage for the duals with the cats?
I'm open to any suggestions.
Rejected in Mass.......................
Rawbin /wwwthreads_images/icons/laugh.gif
1984 CJ-7 304 V8
torx: mistake, or did they do it to us on purpose?
I live in Massachusetts and have a 1984 CJ-7 with a 304 V8 from an older model (circa 1978 or so). I have failed emissions twice now have have a rejection sticker stuck upon my windshield. /wwwthreads_images/icons/mad.gif
RELEVANT HISTORY LESSON ON MY RIDE:
This is what was done to the vehicle by the previous owner(s):
-AMC 304 V8 installed
-headers
-four bbl manifold
-junky 4bbl carburator
-rusty single exhaust (no catalytic converter) /wwwthreads_images/icons/crazy.gif with a SINGLE cherry bomb muffler. (Why they did this after all of the above ....I have no idea)
I rebuilt most of the vehicle over the winter months. Here is what I did to the engine that is related to my topic:
-new Holley 600 4bbl carburator (electric choke)
-Malory Unilite Ignition system upgrade (Unilite conversion part No 501)
I have not touched the exhaust system because I would like to upgrade to a dual exhaust system. I think that time is now. So I went down to my local garage and they preformed an state inspection sticker test. I failed because of emissions. /wwwthreads_images/icons/mad.gif
Now I am not 100% sure of this, but the cutoff year for emission testing on a vehicle here (MASS) is 1983. I miss it by one year. Does this mean that next year my vehicle will be grandfathered in? I am under the impression that I will have to pass emissions this year and after that will be "home free" when it come to emissions testing. Based on this, my goal was to get the vehicle to pass and THEN purchase a dual exhaust system (sans converters) /wwwthreads_images/icons/wink.gif
Here are the results of my emission test:
First Attempt:
Pollutant.....Reading.....Limit..........Pass/Fail
...HC GPM........7.85......3.20..........FAIL /wwwthreads_images/icons/frown.gif
...CO GPM......109.98.....80.00..........FAIL /wwwthreads_images/icons/mad.gif
..NOx GPM........1.73......7.00..........PASS /wwwthreads_images/icons/shocked.gif
..CO2 GPM......654.48
The mechanics couldn't believe that it passed on the NOx GPM because it was missing a catalytic converter. /wwwthreads_images/icons/shocked.gif They advised me that maybe the engine was running too rich and that is why I failed on the other two Pollutant categories.
So I went home, leaned out the carburator till she squeaked /wwwthreads_images/icons/wink.gif filled up with 92 Octane gasoline and added 107 Octane boost with Emission Control ($7.49 for 16 fluid oz /wwwthreads_images/icons/shocked.gif ) and drove around for a few days, then I returned with high hopes of passing, but failed again.
Here are the results:
Second Attempt:
Pollutant.....Reading.....Limit..........Pass/Fail
...HC GPM........7.85......3.20..........FAIL /wwwthreads_images/icons/crazy.gif
...CO GPM.......60.25.....80.00..........PASS /wwwthreads_images/icons/smile.gif
..NOx GPM........1.14......7.00..........PASS /wwwthreads_images/icons/smile.gif
..CO2 GPM......407.78
So I passed on the CO GPM /wwwthreads_images/icons/smile.gif, but still failed on HC GPM /wwwthreads_images/icons/frown.gif
This one exhaust shop offered to install a dual exhaust system with two catalytic converters, but this drove the price up $300.00 /wwwthreads_images/icons/shocked.gif And even after this is done, there would be no guarantee that I'd pass. That would sting and probably leave a mark! If I can, I would rather (space, cost and simplicity reasons) not have to deal with catalytic converters.
Any advice on what should I do? What exactly does a catalytic converter do? Is there any way to adjust timing or something to get it to pass on HC GPM without a catalytic converter? The only adjustments on the carburator are the mixture settings on each side. Or do I need to bite the bullet and spend the extra cabbage for the duals with the cats?
I'm open to any suggestions.
Rejected in Mass.......................
Rawbin /wwwthreads_images/icons/laugh.gif
1984 CJ-7 304 V8
torx: mistake, or did they do it to us on purpose?