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Discussion Starter · #1 ·
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?
 
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Discussion Starter · #2 ·
do you have the air pump on?i have a 1981 f150 that kept failing due to a faulty pump.replaced the pump and passed.

'78 cj-5 grey primer
 
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Discussion Starter · #3 ·
I'm not sure, but I think you might have to use the factory exhaust manifolds w/ the air injection to use an smog pump. The oxygen entering near the exhaust ports aids in combustion of hydrocarbons and carbon monoxide according to the Jeep Owner's bible. I don't know. I actually have to put all the emissions back on my '78 so I can get smog tested in Denver. I put a catalytic converter on before I moved out here thinking that I would need one. Then I got a hold of the 1978 factory service manuals and 78 CJ's weren't equipped w/ cats. Oh well, I do need to put the smog pump back on. I should pass w/ flying colors at any rate. I hope.
The smog pump & cat are the only things I can think of that would help pass emissions. The test is done at idle, not a dyno, right? That means the EGR valve would not be necessary if you tested at idle.

Hopefully someone else knows of a way to pass w/o putting all that crap back on there.

-Jay
Denver, CO
1978 CJ-5 258 Weber, 'glass body
 
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Discussion Starter · #4 ·
If I remember right I believe the HC is raw gas . Does your engine have a slight misfire?? If not try advancing the timing more ,,when the idle goes up lean the carb even more to bring it back down.

 
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Discussion Starter · #5 ·
First off, if your mechanic is not telling how to correct the problem, or at least giving you some ideas, you should find a new mechanic. $300 is pretty good for a dual system, but if you dont have it - you dont have it. So heres a few things that will most likely help; The cats will definately help. Ive heard of some vehicles that pass without them but they are usually MPI engines with a computer to monitor everything going on in the engine - you dont have that luxury. The EGR (exhaust gas recirculation) valve is a good place to start. This valve, as the name suggests, recirculates exhaust gasses through the intake to be burned again, thus "cleaning" the exhaust. PCV - this one confuses me, but I had a vehicle that failed because of this. Please note: my mechanic told me it was the PCV.Somehow the PCV ties into the vacuum and EGR system???? Maybe??? I wouldnt mess with the octane stuff. The difference between high octane and "regular" fuel is that the higher the octane the slower the burn. In fact, this is pure speculation, but you might have better results with lower octane fuel due to a faster, more complete burn. It might be worth a try. Also, give your engine 4°-6° of advance. This will initiate the combustion or "burn" sooner. If all else fails, Ive seen a new set of plugs and wires and a cap and rotor help a vehicle to squeak by. Good Luck and keep us posted.

Holy sh*t thats a long way down!
 

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http://www.motorage.com/edindex/1200feat1.htm
http://people.ucsc.edu/~kbrandt/mustang/smog.shtml
http://www.asashop.org/autoinc/april/tech2tec.HTM
http://ecep1.usl.edu/ecep/auto/n/n.htm
HC is unburned fuel. Misfire, too rich, one cylinder not completely firing? CO follows HC. NOx is opposite, the more fuel effiecent the more NOx comes out. Thus the need for a cat. conv. A converter will help with HC and CO a little also. An air pump will help with HC and CO. an EGR valve and a cat. fixes NOx. Be carful with the advancing timing trick. What happens is as you advance the timing the idle goes up. Then you close the throttle valves a little to compensate. This restricts the amount of air it gets causing a rich condition. Actually the opposite (retarding the ignition) helps emissions by opening the throttle valves more for more O2. This is where an air pump will also help. In NJ 1981 and newer cars have to go on a dynomometer and get checked at idle and I think 30 mph. Older cars just get an idle check and no NOx. Also the GPM specs are unfamilure. Gallons per mile? Good Luck.
 

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If your engine and carb are not tuned correctly, you will not get an efficient catalyst in a catylic converter. I have an 86 CJ, with a chevy 305 that is carburated, and headers and side pipes. I do have the EGR but that is it. I had a brand new edelbrock carb on a edelbrock intake, and I could not pass emmissions for anything. I went to the local carbs unlimited shop, and they could not get it adjusted to work. So, I switched to a quadrajet carb (easy to adjust), and I passed with flying colors.
With the HC, that can come from having the carb too rich, or also from being too lean. If its too lean, its called a lean missfire. Basically there is not enough fuel in the cylinder to promote efficient burning, so you "missfire", and the unburned fuel goes out and ther you have high HC's.

Hope this helped.
TJ

 
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Discussion Starter · #8 ·
GMC350,

Will try to advance the timing. Thanks for your help.

Rawbin /wwwthreads_images/icons/laugh.gif

1984 CJ-7 304 V8

torx: mistake, or did they do it to us on purpose?
 
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Discussion Starter · #9 ·
blakers,

Will try and give the engine 4- 6 advance. Just so you know the $300 was just for the cats, the whole system was $580 /wwwthreads_images/icons/frown.gif

thanks for your help.

Rawbin /wwwthreads_images/icons/laugh.gif

1984 CJ-7 304 V8

torx: mistake, or did they do it to us on purpose?
 
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Discussion Starter · #10 ·
JimmyZ,

Thanks for the links and the information on retarding the timing instead, I will try both ways I guess, trial and error.

I think GPM stands for Gross parts per million. but I'm not sure..

Rawbin /wwwthreads_images/icons/laugh.gif

1984 CJ-7 304 V8

torx: mistake, or did they do it to us on purpose?
 

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Rawbin, you will NOT be grandfathered in, as I currently understand our MASS law. 1984 and newer will be checked every year from now on. I looked into this, as my Jeep is an 88, and I was hoping also, in a few years.

My advice is to put a general purpose cat in your current single exhaust (like $50) or go to the dual cat exhaust if you want.

I think it's unlikely that you will pass without the cat. Just my opinion.

Give thanks that it is only every 2 years that we have to get smogged.

Goodluck,
Pete,
Central MA.

88 YJ - trails/beach trips only!/wwwthreads_images/icons/smile.gif
79 4WD F250-hauler/tower of my toys
70 Jaguar E-type - the best car England ever made. /wwwthreads_images/icons/cool.gif
90 Honda CRX - Daily pavement-pounder. 42 MPG. /wwwthreads_images/icons/cool.gif
 

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Do they do a visual check also looking for emissions equipment? You should contact the DMV there to find out if you will be exempt next year. If that is the case, then you could probably get away with getting a waiver saying you tried to get it to pass but it didn't. I would be very interested to find out about the exemption since I am looking at moving to MA in about a year.

Jay

 

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There is no visual check in MA right now. (God knows what they will do in future years, but right now no.)

You do have to pass the dyno emissions test, but all that matters is what comes out of the tailpipe, not what's under the hood. /wwwthreads_images/icons/smile.gif

So, my weber carb, removed pulse air system, GM HEI, etc., all live happily in the state of massachusetts on my 88YJ. /wwwthreads_images/icons/smile.gif

I did fail for NOx because I had a bad EGR valve, but after replacing that I passed no problems.

Good luck,
Pete

88 YJ - trails/beach trips only!/wwwthreads_images/icons/smile.gif
79 4WD F250-hauler/tower of my toys
70 Jaguar E-type - the best car England ever made. /wwwthreads_images/icons/cool.gif
90 Honda CRX - Daily pavement-pounder. 42 MPG. /wwwthreads_images/icons/cool.gif
 
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Discussion Starter · #14 ·
jdonato-

Double check our 78 CJ manual. I believe that all 78 304 CJs required cats. I have a 78 304 that requires them.

Kriss

 
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Discussion Starter · #15 ·
Kriss, you're right, 8 cylinder CJ's did come with cats. I have a 258-6, however, which did not require a cat.

-Jay
Denver, CO
1978 CJ-5 258 Weber, 'glass body
 
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Discussion Starter · #16 ·
I feel your pain. I live in Kalifornia, king of smog regulations. Dyno, visual inspection AND tailpipe measurements. Engine swaps have to be the same make as your vehicle and the donor vehicle must be same year or newer, with all smog equipment. Smog regulations then are measured from the donor vehicle year. This means that I would fail if I put a brand new fuel injected 350 with all smog equipment and blew nothing but pure oxygen from the tailpipes or swapped in a V8 from the year before mine and blew nothing but warm sunshine (you have to show proof of the year of your donor vehicle). What a load of crap. We currently have exemptions for vehicles 1973 and older, which the commie bastards in our legislative party are trying to repeal. I kept failing last year (5 times)but luckily the mechanic finally had sympathy on my poor moneyless soul and hooked his 74 j-10 w/360 up to the dyno and passed it for me. Turns out (as I would struggle to find out later) that my ignition control module was crapping out on me. TR upgrade here I come!!

--Laugh and the world laughs with you. Cry and the world laughs at you.
 

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Gmoody, look at those CARB restrictions again... I believe the rules demand that to do an engine swap the donor engine must be from the same Class vehicle, not the same make or make...

 

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Prior to my Bronc, i had a F150 with a 302 that wouldnt pass for $H%T. Had a cam , edelbrock intake and carb, High compression 68 heads and the factory CAT. I would then just RETARD the timing 5 or more degrees, till it ran like total crap, and it would pass with results like a new car.

BUT ,then FLORIDA tests may not be as strict/wwwthreads_images/icons/wink.gif...
 
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