1986 Other Suzuki Models Passing emissions, why are my CO le

Tiny
JWBBAZ
  • MEMBER
  • 1986 SUZUKI
  • 4 CYL
  • 4WD
  • MANUAL
  • 148,500 MILES
Have a 86 Suz. Samurai, 4cyl 1.3L trying to get through emissions. First time fail report : HC 4.18 / 3 FAIL, CO 66.17 / 25.00 FAIL, NOX 0.83 / 4.5 PASS. After this test changed Air filter, spark plugs, emptied old gas (car had been sitting for 2 years before I bought it, but was only able to syphon 3/4 of it out), Filled the tank with 87Oct and added Gumout Carb Cleaner & Octane booster, and changed PCV. I went for the second test, extremely improved, but still failed. Fail report #2 HC 2.73 / 3.00 PASS, CO 26.43 / 25.00 FAIL, NOX 1.92 /4.50 PASS. They continue to tell me that I am still running rich, and that is what is causing the problem. Ok. So I go home, replace vacuum lines, replace faulty Vacuum Valve & Mixture Control Valve (ran test and found out they were faulty.) Went to checker to get the parts, and explained my situation, he proceeded to tell me the old try and true method of adding Iso Alcohol to the gas tank & that would help run leaner. Well, I topped of the tank with 91 Oct, added 1/2 pint or so of Alcohol to the tank, ran it all over town and burned up a 1/4 tank of gas, went to the emissions test #3. I went way off the charts again. Fail report #3 HC 3.86 / 3.00 FAIL, CO 69.01 / 25.00 FAIL, NOX 0.93 / 4.50 PASS. I have done repairs for three days now, and on the second test I greatly improved, but cannot understand why I failed again so miserably on the 3rd test. This time instead of telling me I am running rich, and I explained I checked and replaced most of the things that could of been causing that before the 2nd test. They told me it could be my catalytic converter. Is that possible looking at these readings from 3 test that happened with 2 days? How I can go from bad to nearly passing, and then right back to bad? There is black soot & some condensation coming out of the exhaust, which last only a cpl of minutes, but will be fine the rest of the day, usually only happens when the engine is cold. Is there something obvious like the Cat that needs to be replaced, or are the readings showing the problem might lie elsewhere? Thanks for any assistance.
Friday, January 16th, 2009 AT 4:55 PM

5 Replies

Tiny
RACEFAN966
  • MECHANIC
  • 5,029 POSTS
Ok first off you are in the right direction but I would left the alcohol out. Now I must ask how it the power on the car once you get it up to operating temp? Does it lack power under acceloration once warmed up?
Now with the parts you mentioned that you replaced you never mentioned the fuel filter or weather or not you changed the oil. How does the oil look? Now have you ran a test on the O2 sensor? If not then we need to check it all you need a digital multi meter and we can do a simple test to see if it is lazy or hanging up. I was smog tech and a vehicle inpector so I do know something about smog tests. You car could be running rich because the O2 things it is lean and is continuing to correct the problem so. Get back to me and we will go from there.
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Saturday, January 17th, 2009 AT 8:53 AM
Tiny
JWBBAZ
  • MEMBER
  • 3 POSTS
Ok, I checked the oil 4days ago when I bought it, and it seemed to be pretty new, still transparent with little discolor. As far as power after the engine is warm...I'm assuming my power has been increased since I made the changes. The previous owner mentioned to me that he could drive 55 comfortably, and could top out at 60mph. Since the changes I made, I have been able to drive and top out at 70mph without any problem. Car seems to have the power it should have, but it has been almost 15yrs since I owned such an older carburated vehicle, so I really don't know how to base my assumption that I have sufficient power or not.

As far as the O2 sensor, I will check on that. Before I bought the vehicle, I ran a Carfax report, and it noted that the vehicle had failed emissions about 3 - 4 times consecutively in the late 90's and early 2000's. It also mentioned that before it finally passed in 2003, that the O2 sensor had been replaced, as well as the Spark plugs & Wires, Spark controls, PCV system repaired.

One more thing to note, and this may have something to do with the O2 sensor. I noticed when I bought the vehicle (Refer to pictures)


https://www.2carpros.com/forum/automotive_pictures/302995_DSC00238_1.jpg



https://www.2carpros.com/forum/automotive_pictures/302995_DSC00237_1.jpg



This bracket/ring was not even connected to the choke control or spring that regulates the choke, Somehow it had fallen off or became disconnected, leaving the choke on/open 100% all of the time. It was like this when I got it, and I am wondering if this was open all this time and not regulated, would it affect the O2 sensor in anyway?

I noticed this before my first test, but thought nothing of it...wasn't to familiar with the carb or parts, but after the 2nd emissions test that I did rather good on, I saw the round bracket below the assembly, brought it back up, seated it back into it's place and connected the spring. It was after this repair, and changing a vacuum valve that was faulty, that I went off the charts on my 3rd test. The vacuum valve that I replaced and the MCV (Mixture Control Valve) are between the air supply and carb. I didn't have to replace the MCV because I tested it after replacing the vaccum valve and it was working again.

Thanks for your quick response, and I will check the O2 sensor as soon as possible, but if the above mentioned makes any difference or points us in another direction, please let me know, and thanks again for your help.
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Saturday, January 17th, 2009 AT 10:40 AM
Tiny
RACEFAN966
  • MECHANIC
  • 5,029 POSTS
Ok if the chock happens to close a little as the throttle is opened then it will run richer then it should and fail smog. So I would fix the choke problem. Now has this carb ever been rebuilt so that it can be adjusted? If you are not sure then remove the air cleaner and send me a good pic or two of the carb and I will look to see if I can tell.
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Monday, January 19th, 2009 AT 10:51 AM
Tiny
JWBBAZ
  • MEMBER
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As far as the carb being rebuilt...not quite sure, I fixed the choke problem I believe. The following are new pics of the carb, cold, and hasn't been started since yesterday. The choke is closed finally. Before I fixed the linkage it was always open. I did notice something on the carb as I was taking pictures. You'll notice in the first pic, I marked the rubber valve/plunger thing, if you look at the top arrow, you'll notice it is pointing at the very top of the plunger. It seems to be very brittle and torn/cracked. It seems to be leaking, and the plunger itself is wet on the outside, as well as on the carb body. I'm thinking I have just found my problem, but would like to be sure this might have anything to do with running rich or excessive fuel consumption. Thanks again for all your help. But then again, if this seal is broken,wouldn't this cause less fuel getting to the carb?


https://www.2carpros.com/forum/automotive_pictures/302995_Carb_pic1_1.jpg



https://www.2carpros.com/forum/automotive_pictures/302995_DSC00240_1.jpg



https://www.2carpros.com/forum/automotive_pictures/302995_DSC00241_1.jpg

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Monday, January 19th, 2009 AT 11:50 AM
Tiny
RACEFAN966
  • MECHANIC
  • 5,029 POSTS
That is the accelerator pump and that rubber boot is the just that a boot to keep dust and dirt out not fuel in. I would say that this is not going to cause it to fail smog. Now does it look like you can adjust the fuel mixture on it? If so then I would have it smoged then have them adjust it and resmog it. See they can adjust it as they look at the exhaust output and dial it in for you so it will pass. I still think that the carb should be rebuilt if it has not been or if the fuel mixture can not be adjusted. Let me know what you can. Thanks
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Monday, January 19th, 2009 AT 7:31 PM

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