california 60 smog, high CO% low NO no O2 (1 Viewer)

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Anyone have some insight to my test results? I have attached a spreadsheet, yes a spreadsheet of 12 years worth of tests. I do all my own work on the truck for better or worse. I have it running very nice, smooth slow idle but something is not right. Looking at the past tests the two bits of information that stick out are the lack of O2 and the low NO. I have verified the smog pump is working but need to dig into it further, that could be the low O2. Not sure what the low NO means.

Thanks, I question the future of california 60's...
 

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  • CRUISER SMOG LOG 2014-11-08.pdf
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Looks like it's gasping for more/better air. Your total O2 is absent, unless that's an analytic fault. Lower oxygen at detonation yields elevated CO, to varying degrees, lots of variables, but that's the way the plots move.
 
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I agree with more air. The part I am unsure of is at what point, before or after combustion, AI system or valves.
 
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Maybe neither, maybe both, I'm not the expert. Looking at it again, with your total oxides of nitrogen being so low, it almost looks like it's starved for air at the point of combustion, so many of the carbons are not binding to a gas, and they're being blown clear as a particulate, or nearly so.
How's the timing? Can you advance a few degree's without causing pre detonation? If so, how many degree's? If it's more than a couple, that could be the issue. I purposely run a bit rich a few degrees in the interest of saving the engine vs fuel. Here's an example, it's a '62, but the fundamentals are the same, and I can't take mine to a mechanic either.

20141109_15530714955.jpg
 
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Pilfered from the web:

Carbon monoxide results from incomplete combustion of fuel. Incomplete combustion is most likely to occur at low air-to-fuel ratios in the engine.

Some causes of high CO
  • Dirty air filter
  • Incorrect float level
  • Wrong timing
  • Malfunctioning PCV
  • Dying catalytic converter
(for a start)

Here is my last two CA smog tests for reference. '86 FJ60. Same shop. Car has a good Cat but engine had low-ish compression due to leaky exhaust valves.

smog.jpg
 
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Thanks for the advise, I have replaced all tune up parts and the cat only has 6k on it so it is something deeper. I am going through the air injection and am suspecting the top of the ABV. Does anyone know if the top two ports should hold vacuum? I can not get the valve to open (lower port), only just loosen and can tell it is leaking out the other port and somewhere else. This would mean no air in the exhaust and could be the problem.

20141109_162958 (1).jpg
 
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I have been reading that tattered oil stained book all afternoon... I am pretty sure from the diagrams that the top diaphragm on the ABV is supposed to leak but I do not see how to test it. The second test in the emission control manual is "check ABV" I could not get it to burp air when dropping the throttle, I will check the VSV's next.
 
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Since my engine passed it's recent smog test, I assume my AI system is working correctly.
I just checked my ABV/ACV assy. right now to verify your findings. It is off the car at the moment.
This is what my AI ABV/ACV assy does:

  1. When vacuum is applied (using a hand actuated vacuum gauge) to the upper ABV nipple, no resistance is felt, no vacuum is held. Essentially a free flow. No valve can be heard closing.
  2. When vacuum is applied to the lower ABV nipple, the diaphragm can be heard closing for a moment, but the vacuum leaks out after a second or two and the valve closes.
  3. When vacuum is applied to the ACV nipple, the diaphragm closes and vacuum is held. No leaks.
 
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Output Shaft, Thanks much for the confirmation. The FSM has what looks like a small hole in the diaphram in the drawing but was not sure. Mine tests exactly like yours. I have cleaned out the insides and will move on to the other components...
 
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Whatever the culprit, elevated CO is specific to insufficient oxygen, and low (non existent) nitrogen = insufficient total air throughput, at the point and time of combustion. It would be nice to know other analytes, but with what you've got, and without a clear indication with the way it's running; starting, idle, high rpm or load misfire, I think the air flow volume must be there, but it's not getting flamed at the right time.
Other stuff, like lousy fuel or fuel metering, I think would present performance you'd notice.
 
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I wish the old SUN engine analyzer from high school shop was still around... It actually runs very nice but I feel like it does not smell right on occasion. The idle is steady at around 700rpm vacuum at steady 17.5, easy driving even with the EGR connected. My suspicion at this point is the air is not going to the right places at the right times.
 
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Your problem really is all of ours with FJ60s here in CA, because something like this is bound to happen to all of us eventually. So it is in our best interest to find out the cause of your smog test failure.. if for no other reason than to save our own butts in the future.

The smog pump (via a properly functioning AI system) is supposed to inject air into the air injection manifold at the speeds that are tested during a smog test (below 35 mph).

Air flows through the AI manifold at these speeds except during deceleration, when it is then bypassed to the exhaust pipe… but you don't care about deceleration during a smog test and neither do they.

It seems like a lot variables within AI system could be ruled out at the next smog test by simply routing the smog pump outlet hose directly to the check valve on the air injection manifold. That way you would know that air was definitely being blown directly into the exhaust ports at all times during the test.

While you have the hose disconnected from the air injection manifold, you might want to make sure that you can blow air through the check valve with lung power. If it is difficult to blow air, replace the check valve as a precaution. They are relatively cheap.

At the next smog test, you might need to explain to the technician that you are trying to pinpoint the problem with your bypass hose because a smog technician would not normally pass the car based on visual inspection with a jury rigged hose.

If the engine still failed with this jury rigged setup, then you would know that the problem is not with the AI system and you could then rule it out as the cause.

If the engine passed, then the cause of past failures was due to something in the ai subsystem…. ABV assy. VCVs etc. but not the smog pump specifically.

At least that is how I would take the next step without spending a boatload of cash. Maybe others have a better idea.
 
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Excellent insight. I keep over thinking this and forget that the test is actually very limited. I am pretty sure I can set it to always send air to the exhaust ports with the vacuum lines and that may be the next step. As systems fail and parts become extinct "tuning for the test" may become the norm for California 60's.
 
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I had similar problems, but the AZ test is much simpler - they just look to see there is a non-venting gas cap, an air pump, an EGR valve and a catalytic converter...but then you have to blow clean at idle and at 35mph...

It seems like a lot variables within AI system could be ruled out at the next smog test by simply routing the smog pump outlet hose directly to the check valve on the air injection manifold. That way you would know that air was definitely being blown directly into the exhaust ports at all times during the test.

I did this too and it worked.

My 87 had High CO at 35mph (the loaded test) and I think my computer was fubared and not letting the VSV (2) open - letting air to the top of the ABV valve - allowing the vacuum to pull the ABV open. I tricked the ABV into staying open all the time, injecting air into the exhaust pipe all the time, by letting the top port of the ABV vent to atmosphere without hooking it up to the VSV (2). If you want a stock looking system, you can keep the hoses hooked up in the stock locations, drill a small hole in the vacuum hose between VSV (2) and the ABV allowing venting to the atmosphere 100% of the time. This bypasses the emissions computer. It also won't let the ASV work at low speeds but I think my air rail is plugged up with carbon so no loss there. Besides, more air on the back end can't hurt. Unless you think this might cause the CAT to overheat? I only run it this way to pass the test. Your results may vary ...

upload_2014-11-12_9-39-27.png


Saludos

Geoeng
 
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I had a chance to go through this a little more.

1. I disassembled the ABV, tested all of the valves and reassembled. It functions and redirects the air as it should.

2. The Emission control manual shows five options for the air from the pump, per Output shafts observation I only need it to pass the test so make it work there.

3. The california test is for 15 and 25 mph steady, the deceleration fuel cut system should not come into play.

4. The only options left are injected to exhaust ports and bypassed to air cleaner, based on the OC temp.

5. I would assume during the test there should always be air flowing into the exhaust and per the manual it should go to the exhaust ports.

based off of these thoughts I have diagrammed what should be the only mode that it should run in during the test and how I think all of the other variables can be removed without alerting the smog tech (for once all of those hoses will come in handy as switching those two would never show)

Any thoughts? Could this be a way around the computer and some of the difficult switches and valves?
 

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Dynosoar

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A standard .177 BB works perfectly to block the stock vacuum lines. Your plan looks solid just don't run it that way all the time or you will overheat the cat.

Dyno
 
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It looks like you have thought through the details more than any of us have so far. Double check you logic to be sure. To confirm, you could remove the hose going to the check valve on the air injection manifold to make sure that air is at least getting pumped out that hose from idle to 1800 rpm... Then give it another whirl. Make sure your rear tires are filled to max psi before the test. That will lower their rolling resistance so the engine won't need to work quite as hard = lower emissions.

By the looks of it, your cruiser has 31" tires installed.
If your cruiser was tested running 225/75R15 tires (the original 28.3" tires installed from the factory), your RPMs would increase approximately 9.1% to about 1850 RPM during the test… which is the sweet spot for maximum torque. Right now your engine is lugging it during the entire test at those speeds with your tires = higher emissions.

Testing an engine at 1560 RPMs is moronic and criminal and certainly below the normal cruising RPM of the engine. No one cruises at 1560 RPM…What a ridiculous test!

Here is a LINK to some good pre-smog-test tips. I bet you know most all of them already.
& don't be discouraged if it fails again.. The problem may not lie with the ai system after all. But at least then (if it fails) you will have ruled out the ai without $pending 2 much $.

Keep us posted..
 
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Output Shaft, Your observation on the RPM is spot on. The tires are 33 x 10.5 and it has an H55 transmission. The transmission helps a bits with the ratio but I can tell the low RPM is right at the point where the EGR starts to kick it at it's worst... A few years back I actually borrowed some stock wheels for the test and I think it helped.

I adjusted the valves today, a little tight but close. Will change the oil next.

The linked article did have a few good tips on testing when it is cool / damp outside and running premium, not sure I can do much with the clean and shiny part.

So far I am avoiding making my own ethanol
 

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