1979 dodge mobile traveler 360cl wont pass emissions

The humor continues.

The OP likely does not have the finances to buy anything newer, thus why they signed up to this forum, just to ask a question on how to get their likely new to them antique RV, that they are intending to live full time within, to pass a smog test.

Seems highly unlikely he she/them are just fans of 1979 vintage RV's.

They likely have confused CO, with CO2, and have little to no ability to work on their own stuff, much less diagnose issues. Changing the Spark plugs and an oil change, could be the near limits of their abilities, and they came here hoping someone with lots of experience with that particular RV/ engine combo could point them in the least expensive direction so they could get that magic legal sticker/ paper, and worry instead, about all the other things that those with limited finances worry about.

But please elaborate more about your multiple antique vehicles and how great you are. I'm sure the OP, if they ever bother returning, is in complete awe.

landyacht318 wrote:
Try and find the humor in your waste of time.

I like the recommendation that the owner of a 40 year old rv just buy something newer, because obviously they have lots of money laying around, and they came to a RV internet forum for help as all the high $$ mechanics in their area were dumbfounded.

Regarding Co vs CO2, how many threads on this forum have had questions or comments about about the parasitic draw of their CO2 detector, and specify it as co2 multiple times?

Nazifornia lists no allowable CO2% parameters, but Utah does?
Seems unlikely.

Not "humor" or even "sarcasm" with my suggestion.

I DO have sever antique autos, one that is 118 yrs young and one that is 46 yrs young.

NEITHER vehicles are practical for EVERY DAY USE, PERIOD..

BOTH vehicles consume HUGE AMOUNTS OF TIME AND MONEY just to keep them is "derivable" condition for OCCASIONAL USE.

I GREW UP working around engines (Hit and Miss oil well engines) and equipment OLDER THAN YOU (unless you are 100 yrs old).

Finding a mechanic that even has a clue what a carburetor is on a automobile and how to adjust it is like pushing a boulder up a mountain WITH YOUR NOSE is pretty much not happening.

Most of those good mechanics which worked on vehicles in the 1970s and before are retired OR DEAD.. The kids of those mechanics sold the business and or scrapped the equipment because they didn't have a clue, didn't understand, didn't care, could be bothered with old technology.

Heck 10 yrs ago, my Dad couldn't even find a mechanic that could work on a 1987 EFI engine with OBD1, most of the mechanics had tossed out the shop manuals AND EQUIPMENT.

Sorry, A 40 yr old MH is not worth much, tossing a lot of money and energy into a 1979 vehicle such as that is pretty much flushing good money right down the sewer system.. Whats the OP going to do in 2 yrs when it doesn't pass AGAIN?

A 1979 engine IS a wimp, it eats fuel like it is going out of style and barely had enough power to make it up steep hills. 1970s was not "kind" to automobile engines with the mandated pollution stuff.. Wasn't until you get into the late 1990s, early 2000 before you started to get engines much, much more powerful (AND FUEL EFFICIENT).

Yeah, I remember when my Dad bought his 1980 truck, 400 CID with 4.10 axle, 11% grade up hill EMPTY it topped out at 40 MPH! Empty mileage was barely 6 MPG with a stiff wind to your back, loaded with a TC was getting 4 MPG!

Don't give me that pity party thing about money, if you can afford the fuel you are feeding it, should not have much of a issue with finding a slightly newer than 40 yr old MH which will get better fuel economy (saving you money) and have considerably better power..

Parts for that old stuff (especially Dodge) is not easy to find nor cheap.. Heck for my 46 yr old antique car I have had to MAKE nearly every body part by hand.. Some mechanical parts I have to MATCH other parts from similar body/chassis of different vehicles..

And forget about finding parts for my 118 yr old antique, those parts are not sold in stores and I must MAKE EVERY THING BY HAND WHEN IT BREAKS..

While I suspect the OP might be able to get the CO2 near the requirements this time, the next time down the road the emissions requires CAN be "tightened up" to the point it will never pass! Seems to me, the OP is buying only a couple more yrs in their state..

You can thank a lot of the green folks for this, it is planned obsolescence via "emission testing/regulations"..

Perhaps take a step back and think of it like computers, 1979 vehicle would be like trying to operate a Commodore Vic 20, Atari 400, Timex Sinclair on the Internet today.. That technology was cutting edge back then, now, not so much..

We need a public nick-name for double-digit IQ questions such as the 21 reasons a battery cannot be removed and tested at a parts store for free. Six pages of exotic permutations.

Try and find the humor in your waste of time.

I like the recommendation that the owner of a 40 year old rv just buy something newer, because obviously they have lots of money laying around, and they came to a RV internet forum for help as all the high $$ mechanics in their area were dumbfounded.

Regarding Co vs CO2, how many threads on this forum have had questions or comments about about the parasitic draw of their CO2 detector, and specify it as co2 multiple times?

Nazifornia lists no allowable CO2% parameters, but Utah does?
Seems unlikely.

The OP abandoned ship. I passed the NIASE test for emissions in 1979. Curing the alphabet stew of emissions complaints had to be studied then tested. As a 6-month stint for MoPar line mechanic I have lots of experience with 360 and 440 engines.

That was 40-years ago.

Are any forum members capable of a factory quality rebuilding of a Carter Thermoquad carburetor? Or emissions test qualification? I had access to Factory Technical Tip Bulletins when the carburetor was brand new.

The OP asked a specific question and he specified CO2 not CO. I responded to that question. He since disappeared. Waste of time, except to folks that actually own and use and register that era's motor vehicles. High CO2 is a CLUE to troubleshoot OTHER emissions problems.

I should have known better than waste my time. Shame on me.

I know this is apples and oranges - BUT

When I had an ole dodge Dakota that thing would never pass emissions, even after dropping money at the stealer and they swore it was OK.

So long comes an idea that is out in left space. it was the time that AMACO was advertising the ultimate grade that you could see thru in the glass full of it.

i drove the vehicle down to as much as I dared towards empty. Even carried a little spare gas if i got empty.

Then drove into the AMACO station and dumped some ultimate in it. Took it out and let her eat on the free way for some miles. Then zipped into the station that was always flunking the test and it passed with flying colors. i did the same for the following years.

just my story and I am sticking to it. good luck with that beast.

BTW at the time they even sold snake oil that was supposed to help, but that didn't work on my Dodge.

Airdaile wrote:
You should investigate the requirements and restrictions if you were to register your motor home as an antique.

That WOULD most likely make the vehicle as designed IMPOSSIBLE to use for its intended purpose of camping.

Antique plates in many states WILL add considerable usage restrictions like a max mileage per yr, no or limited operation at night, only one day per week usage, only allowed to be driven to and from car shows or events, ect.

I suspect the DMV most likely would not accept a motorhome for antique plates..

OP simply needs to find a good quality old school mechanic with some diagnostic equipment to measure CO2 while making carb adjustments.. It should be do able but finding a mechanic now days that doesn't need to plug into OBD ports to fix things is getting to be very rare..

Not sure why the OP hasn't been against this wall before.. New in the state?

For all the hassle in such an old MH, perhaps it's time to move on?

After all, we ARE talking about a 40 yr old vehicle, with 40 yr old emission technology which was totally experimental back then.

Something newer will have considerably more powerful engines with fuel injection much improved emission systems and so on..

You should investigate the requirements and restrictions if you were to register your motor home as an antique.

The OP is in Utah, It would be nice to see a printout of all the things they are testing for, in Utah, to make any guess as to what might be the issue.

In California, which is likely the strictest of any state regarding allowable exhaust emissions:
---CO is measured as a percentage, and my TBI '89 LA 318(5.2l) Dodge is allowed 0.5% at 15mph and 0.64% at 25mph.

----CO2 is given as a percentage, but no maximum or minimum allowable % is listed, mine just measured 13.3% at both 15 and 25mph.

------O2 is listed as a percentage, but no min or max allowable % is listed, Mine measured 2.4 an 2.5% at 15 and 25mph.

It is difficult for me to imagine that Utah has stricter requirements than California in regards to CO2%, and that California does not state the allowable limits clearly, while Utah does.
So I urge the OP to recheck whether the CO2 or the CO is the issue as many people confuse the 'two'.

HydroCarbons, in California, are measured in PPM and the max allowed for my vehicle is 102PPM at 15mph, and 120PPM at 25mph.

NO is measured in PPM, and my vehicle's max allowed is 1010 at 15mph and 870 at 25mph.

Yes, the drive axle is put up on rollers during the test on OBD1( 1996) or older vehicles in my county/zipcode in this state. More rural areas likely are not.

They do visual inspection of the presence all the original smog related components, but they do not test the actual output of the smog pump, or see if the pintle is moving as it should on the EGR valve.

The Intake crossover is designed to heat the carb/throttle body of a cold engine faster, and should have no effect on the smog numbers once it is hot. All vehicles should be at full temperature when smog tested. Note that while the engine coolant might take 10 minutes to read its maximum, the oil takes much longer to warm up and it is much better if it is at full temperature when the vehicle is Smog tested.

The intake crossover is designed to allow better driveability and lower emissions with a cold engine, while it is warming up, and should have zero effect on hot smog numbers. If they were testing for the function of this feature as to the Smog numbers, they would have to start with an overnight cold engine. Obviously they cannot, and do not.

The bimetal spring operated valve on the passsenger side exhaust manifold of my 1989 318, which redirects gasses through the intake manifold on mine is broken, I have clamped it off fully open, and it never redirects any air through my intake manifold. It has been this way for my last 7 California smog tests(14 years), all of which I have passed the first try. It is visually inoperable, with hose clamps compressing aluminum foil on the shaft to prevent it from rattling or leaking.

A well running engine should have little issue passing a smog test.

My Smog test cost 73 dollars yesterday, and they knocked off money to this total, after I told them I would have the engine cover removed when I brought it in. Forcing the smog tech to do this is not going to make them happy, and they might not spend the time to make sure it is as hot as it should be for the sniffer part of test. When smog techs see an RV or a VAN and especially conversion vans with teh frou frou engine covers, they sigh audibly, and most stations charge significantly more for these vehicles because of the engine cover removal and return, can be a tedious and annoying, time consuming process.

There are all sorts of products, Like CRC 'guaranteed to pass' which are primarily designed as fuel and combustion chamber cleaners which should help lower the CO NO an HC's. These fuel add products have high levels of poly ether amine, PEA, which is supposed to clean the intake valves and combustion chamber without leaving any residue of its own. Other Fuel system cleaner type products have PEA, not all of them do. These are said to be most effective in cleaning the combustion chamber and intake valves, when heat cycling the engine, hot and cold, as opposed to a long drive on the highway. They are not add to the tank and then immediately take it to the test facility style of products. One needs to burn them though ~15 gallons of fuel so they have the time to do their job.

Some swear by adding ethanol to the gas to help pass smog tests immediately. DeNatured alcohol is Ethanol, with toxic denaturants added to keep drunks from swilling it, and government from taxing it, yet at ~8$ a liter is hardly inexpensive. One might be able to simply add some E85 to their gas tank and be able to pass the sniffer test.

Lots of people swear by water decarbonization of intake valves and combustion chambers which will help the engine to run cleaner and more efficiently. To do so, One needs to mist distilled water into the intake, while feathering gas pedal to not allow the engine to stall while doing so. One must be careful to not allow it to hydrolock. Obviously there is a huge risk if done improperly. I've never done so.

The smog tests are a bit asinine in some ways, as the smog pump itself injects so little air into the exhaust stream that its intent to help further burn any unburnt hydrocarbons is likely ineffective, and all it does is add parsitic drag to the engine making it less efficient. My spark timing is to be set at 10 degrees before top dead center and needs to be within 3 degrees of this to pass smog. They do test this with a timing light. My engine runs so much smoother and better with timing set at ~16 degreees. I have no proof it is more efficient and makes lower smog numbers at 16 degrees BTDC, but I do bust out the timing light every two years, twice, once before and once after the test.

My Smog pump tends to seize quickly if disconnected, so I just leave mine operable to make extra putt putt noises, and rob my engine of HP and torque, and in general irritate me.

If the old spark plugs you changed had pure white insulators with perhaps blisters on the center electrode then the system is running too lean. That eliminates the ignition system.

Get a can of starting fluid, and if you can find a tip that fits that takes a plastic straw. Set the engine idle to 1000 RPM. CAREFULLY squirt around the base of the carburetor.
bit by bit check the carb throttle shaft bores, Then around manifold fittings.

If there is ANY noise change or RPM stumble from the engine speed, you've found your culprit.

There are a ton of tiny vacuum tubes on the intake manifold and carburetor. Go to the parts store and buy a three feet piece of this hose.

Disconnect one-by-one the hoses that lead to the choke pull of diaphragm, the secondary of the Thermoquad and the vacuum advance on the distributor.

Suck on the hose. No resistance -- is the culprit. That's a vacuum leak.

No push-back on the brake pedal after pumping it several times then holding it down hard and starting the engine is a "tell".

Leaks in the air injection reaction system will cause a lean high CO2 reading.

A tachometer will "tell" when noise is too high to hear subtle engine speed changes.

All of this will take longer than an hour. I vigorously encourage the use of a tachometer. Take your time being meticulous. I used a vacuum hand pump with gauge instead of my mouth to test vacuum components.

Good luck to you.